Oracle® OLAP DML Reference 10g Release 1 (10.1) Part Number B10339-02 |
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The SQL command passes instructions written in Structured Query Language (SQL) to the relational manager from Oracle OLAP. Using the SQL command, you can insert and update data in relational tables, retrieve data from relational tables into analytic workspace objects, and execute stored procedures.
To use the SQL command, you must be familiar with SQL syntax and with the data structures in your relational database. SQL*Plus Worksheet and Oracle Enterprise Manager can be useful tools for browsing through your database.
This entry describes the SQL command in general, and subsequent entries discuss the use of the OLAP DML SQL command for specific SQL statements:
Syntax
SQL sql-statement
Arguments
For sql-statement you can specify most SQL statements that can be executed dynamically, as well as several associated non-dynamic statements.You can also specify PROCEDURE for a stored procedure as described in SQL PROCEDURE.
You cannot specify the following SQL statements for sql-statement :
COMMIT
-- To commit your changes, issue the OLAP DML COMMIT command.
ROLLBACK
-- You cannot rollback using the OLAP DML. When you specify SQL ROLLBACK
, you receive an error message stating that ROLLBACK
is not supported as an argument to the OLAP DML SQL command.
Important: When you use the OLAP DML SQL command to request a rollback in some other fashion (for example, using SQL EXECUTE), Oracle OLAP issues a system error message, abnormally terminates the OLAP DML program that issued the command. Oracle OLAP also detaches, in an indeterminate state, the analytic workspace that contains the OLAP DML program that made the rollback request and any other attached analytic workspaces with uncommitted updates. |
Oracle OLAP evaluates some SQL statements before sending them to the relational manager. For example, Oracle OLAP evaluates SQL PREPARE and SQL EXECUTE, and SQL statements that copy data from relational tables into analytic workspace objects (See "Copying Relational Data into Analytic Workspace Objects" for a list of these statements).
Notes
You can copy relational data into analytic workspace objects using either an implicit cursor or an explicit cursor:
To copy data from relational tables into analytic workspace objects using an implicit cursor, use the SQL SELECT command. You can use this OLAP DML command interactively in the OLAP Worksheet or within an OLAP DML program.
To copy data from relational tables into analytic workspace objects using an explicit cursor, use the following commands within an OLAP DML program in the order indicated:
SQL DECLARE CURSOR defines a SQL cursor by associating it with a SELECT statement or procedure.
SQL OPEN activates a SQL cursor.
SQL FETCH and SQL IMPORT retrieve and process data specified by a cursor.
SQL CLOSE closes a SQL cursor.
SQL CLEANUP cancels all SQL cursor declarations and frees the memory resources of an SQL cursor.
Oracle OLAP evaluates all of these statements before sending them to the relational manager.
For the syntax of these statements, see the individual topics. For the syntax of other SQL statements, refer to the Oracle Database SQL Reference.
A number of options are available to you when embedding SQL. These options are listed in Table 22-1, "Embedded SQL Options".
Table 22-1 Embedded SQL Options
Statement | Description |
---|---|
SQLBLOCKMAX |
An option that contains the maximum number of records retrieved from an Oracle relational database at one time. |
SQLCODE |
(Read-only) An option that contains the value returned by the Oracle RDBMS after the most recently attempted SQL operation. |
SQLERRM |
(Read-only) After the Database reports an error and SQLCODE has a nonzero value, an option that contains the text that explains the problem. |
SQLMESSAGES |
An option that determines whether error messages are sent to the current output file. |
Before you use the SQL command, ensure that you have access rights to the tables that you want to use.
In this topic, OLAP DML is the "host language," an OLAP DML program is a "host program," and an OLAP DML variable used within a SQL statement is a "host variable." There are two types of host variables: input host variables and output host variables. Host variable names must be preceded by a colon (for example, :MYVAR).
Input host variables are values supplied by Oracle OLAP as parameters to a SQL statement. They specify the data to be selected or provide values for data that is being modified.
You can use input host variables in SQL WHERE
clauses, parameter list for procedures, UPDATE
statements, and the value clause of INSERT
.
When you specify a dimension or a dimensioned variable as an input host variable, the first value in status is used; no implicit looping occurs, although you can use a FOR or ACROSS command to loop through all of the values. An input host variable can be any expression with an appropriate data type. The value of an input host variable is taken when a cursor is opened, not when it is declared. See Example 22-1, "Inserting Data in a Table".
To update or insert relational CLOB and NCLOB data, you use WIDE
in the host variable for the OLAP DML expression as described in "Inserting Large Text Values into a Table" .
Oracle OLAP can detect some syntax errors in the arguments to the SQL statement, but most errors are detected by the Oracle RDBMS. Error codes and messages are returned to Oracle OLAP. You should check the value of SQLCODE after each SQL statement to determine when it resulted in an error. When it does cause an error (that is when SQLCODE EQ -1
), check the value of SQLERRM for information about the cause of the error.
SQL
UPDATE
statements can contain a WHERE
clause, which specifies a particular search condition. In addition to the search conditions typically used in SQL, the phrase WHERE
CURRENT
OF
cursor
is supported for single tables and views that include columns from only one table. The cursor must have been defined with the FOR
UPDATE
clause.
Refer to the notes for SQL PREPARE and SQL EXECUTE.
A SQL statement cannot exceed 128K bytes including the values of all non-text input host variables.
Examples
Example 22-1 Inserting Data in a Table
You can use SQL statements such as the following to create a table and add rows to that table. The SQL INSERT statement adds a row to the sales
table using values from the dimension salesperson
and the variable dollars
. It adds one row using the first value of salesperson
that is in status.
SQL CREATE TABLE sales (name CHAR(12), dollars INTEGER) SQL INSERT INTO sales VALUES (:salesperson, :dollars)
The SQL CLEANUP command cancels all SQL cursor declarations and frees the memory resources for all SQL cursors. After you have cancelled SQL cursors, you cannot use them again unless you issue new SQL PREPARE, SQL DECLARE CURSOR, and SQL OPEN commands.
Syntax
SQL CLEANUP
Notes
You use the SQL CLEANUP command in combination with other SQL commands to copy data from relational tables into analytic workspace objects as outlined in "Copying Relational Data into Analytic Workspace Objects".
Examples
For an example of the use of SQL CLEANUP, see Example 22-11, "Fetching Data into a Concat Dimension".
The SQL CLOSE command closes a SQL cursor. After you have closed a cursor, you cannot use it again unless you issue a new SQL OPEN command.
Syntax
SQL CLOSE cursor
Arguments
The name of a cursor previously opened with a SQL OPEN command.
Notes
You use the SQL OPEN command in combination with other SQL commands to copy data from relational tables into analytic workspace objects as outlined in "Copying Relational Data into Analytic Workspace Objects".
You can change the result set associated with a cursor by closing the cursor, setting the value of an input host variable, and issuing a new SQL OPEN command. You do not have to free the cursor and redeclare it.
The SQL DECLARE CURSOR command defines an explicit SQL cursor by associating it with a SELECT
statement or procedure. The SELECT
statement specifies the scope of the data (the rows and columns) selected by the cursor.
Two pseudo procedures, SQLTABLES
and SQLCOLUMNS
, allow you to obtain information about tables and columns.
Syntax
SQL DECLARE cursor CURSOR FOR {select-statement [FOR UPDATE]|table-info}
where table-info can be used only when declaring a cursor for use by the SQL FETCH command and is one of the following:
PROCEDURE SQLTABLES [owner, table]
PROCEDURE SQLCOLUMNS [owner, table, column]
Arguments
The name of the cursor you are defining. See "Cursor Names".
A SQL SELECT statement that identifies the data you want to associate with the cursor. For the syntax of an SQL SELECT statement, refer to Oracle Database SQL Reference.
Indicates that SQL FETCH will be used to write data to the table. This clause is required when the cursor will be used in an UPDATE
statement with a WHERE
CURRENT
OF
cursor
clause. The names of the columns to be updated can be listed in an OF
clause (for example, FOR
UPDATE
OF
COL1,
COL2,
COL3
).
When declaring a cursor for use by SQL FETCH, calls the pseudo procedure SQLTABLES
, which returns information about tables. When declaring a cursor for use by SQL IMPORT, you cannot use this clause.
When declaring a cursor for use by SQL FETCH, calls the pseudo procedure SQLCOLUMNS
, which returns information about columns. When declaring a cursor for use by SQL IMPORT, you cannot use this clause.
Literal text or the name of a host variable whose value specifies one or more owners. This expression acts as a filter to limit the results to only tables belonging to the specified owners. The keyword NULL or a host variable with an NA
value causes all table owners to be included in the results.
The expression can be specific, such as 'SCOTT'
, or it can contain wildcard characters such as 'S%T'
(all owners whose name begins with S
and ends with T
). The value retains its case when it is passed to the database, so be sure to enter the value with the appropriate use of upper- and lowercase letters. For example, Oracle relational databases by default store all values in uppercase and will not match 'scott'
or 'Scott'
with 'SCOTT'
.
Literal text or the name of a host variable whose value specifies one or more tables. This expression acts as a filter to limit the results to only tables with the specified names. The keyword NULL or a host variable with an NA
value causes all tables to be included in the results.
The expression can be specific, such as 'PAYROLL',
or it can contain wildcard characters such as '%ROLL'
(all tables whose name ends with ROLL
). The value retains its case when it is passed to the database, so be sure to enter the value with the appropriate use of upper- and lowercase letters. For example, Oracle relational databases by default store all values in uppercase and will not match 'payroll'
or 'Payroll'
with 'PAYROLL'
.
Literal text or the name of a host variable whose value specifies one or more columns. This expression acts as a filter to limit the results to only columns with the specified names. The keyword NULL
or a host variable with an NA value causes all tables to be included in the results.
The expression can be specific, such as 'SALARY'
, or it can contain wildcard characters such as 'SAL%'
(all columns whose name begins with SAL
). The value retains its case when it is passed to the database, so be sure to enter the value with the appropriate use of upper- and lowercase letters. For example, Oracle relational databases by default store all values in uppercase and will not match 'salary'
or 'Salary'
with 'SALARY'
.
Notes
You use the SQL DECLARE CURSOR command in combination with other SQL commands to use an explicit cursor to copy data from relational tables into analytic workspace objects as outlined in "Copying Relational Data into Analytic Workspace Objects".
The following restrictions apply to the SQL DECLARE CURSOR command:
You can use it only in a program.
It cannot contain ampersand substitution.
When declaring a cursor to be used by the SQL IMPORT command, you can only use the following simplified syntax.
SQL DECLARE cursor CURSOR FOR select-statement
where select-statement is a SQL SELECT
statement that identifies the data you want to associate with the cursor. You cannot use the FOR
UPDATE
clause or the table-info
clause.
Cursor names can consist of 1 to 18 alphanumeric characters or the symbols @
, _
, $
, or #
. A name that contains symbols @
, $
, or #
must be enclosed in single quotes. The first character cannot be a number or an underscore. Cursor names are internal to Oracle OLAP. Unless you have issued a SQL CLEANUP statement, when you try to declare a cursor with the same name as a previously declared cursor, but with a different SQL SELECT
command, an error is signaled.
A cursor's result set is determined at the time it is opened, and it is not updated later. Therefore, when you change the value of an input host variable after you open its cursor, the change does not affect the cursor's result set. A cursor remains open until a SQL CLOSE command is executed for that cursor or until a SQL CLEANUP command closes all cursors. A cursor is not automatically closed at the termination of the program in which it was opened.
When fetching values into a multidimensional input variable, list the columns that correspond to the dimensions in an ORDER BY clause in the select-statement argument of the SQL DECLARE CURSOR command, with the slowest-varying dimension first. This will optimize performance.
The select-statement argument of a SQL DECLARE CURSOR command can include a WHERE clause. Since both OLAP DML syntax and SQL syntax allow you to use AND and OR, you should construct the clause clearly so that Oracle OLAP can identify the end of an input host variable. For example, the following WHERE clause is ambiguous, because the first host variable could be either ":MARKET AND PRDCODE" or simply ":MARKET."
... SELECT ... WHERE mktcode = :market AND prdcode = :product
Use the following construction instead.
... SELECT ... WHERE :market = mktcode AND :product = prdcode
You can also use parenthesis to clarify the syntax, particularly when using a SQL operator that is unknown in Oracle OLAP.
... SELECT ... WHERE (mktcode = :market) AND (prdcode LIKE :product)
SQLTABLES is a pseudo procedure that returns the following values for each table that matches the search criterion. See Example 22-3, "Discovering Information About Relational Tables".
tableowner -- A text value identifying the owner of the table.
tablename -- A text value identifying the name of the table.
tabletype -- A text value identifying the type of table using one of the following: TABLE, VIEW, SYSTEM TABLE, ALIAS, SYNONYM, LOCAL TEMPORARY, GLOBAL TEMPORARY, or NA
(indicating an unrecognized type).
SQLCOLUMNS is a pseudo procedure that returns the following values for each column that matches the search criterion. See Example 22-4, "Discovering Information About the Columns of a Relational Table".
tableowner -- A text value identifying the owner of the table.
tablename -- A text value identifying the name of the table.
colname -- A text value identifying the name of the column.
coltype -- A text value identifying the data type of the column.
olaptype -- A text value identifying the data type that most closely matches coltype.
length -- An integer value identifying the length of column values.
precision -- An integer value identifying the precision of numeric column values.
scale -- An integer value identifying the scale of column values.
nullable -- A text value of Y
or N
indicating whether the column can contain null values.
Examples
Example 22-2 Testing for the Value of SQLCODE
Cursor c1
is declared for three columns in the table mkt
, which is owned by user sqldba
. Values from the three columns are fetched into three analytic workspace objects. The first host variable is the market
dimension, which is temporarily limited to the retrieved value. Because of the temporary status of market
, the other column values are assigned to the appropriate cells of the other host variables.
This example tests the value of SQLCODE in two places. A more complete program would do more error checking.
DEFINE market DIMENSION TEXT DEFINE mkt.desc TEXT <market> DEFINE mkt.abbrev ID <market> DEFINE sql.market PROGRAM PROGRAM TRAP ON ERROR SQL DECLARE c1 cursor FOR - SELECT mktcode, mktabbrev, mktdesc FROM sqldba.mkt SQL OPEN c1 IF SQLCODE NE 0 THEN SIGNAL SQLERR 'open cursor failed.' WHILE SQLCODE EQ 0 SQL FETCH c1 INTO :APPEND market, :mkt.abbrev, :mkt.desc SQL CLOSE c1 ... RETURN error: ... END
Example 22-3 Discovering Information About Relational Tables
The following program fetches information about all tables owned by Scott
. Notice that the value of the ownername variable is set after the SQL DECLARE cursor command; it can be set any time before the SQL OPEN command. The tablename variable is not set, but is initialized automatically to NA
, which is passed as a null value.
DEFINE ownername TEXT "Search criteria DEFINE tablename TEXT "Search criteria DEFINE tblowner TEXT "Search results DEFINE tblname TEXT "Search results DEFINE tbltype TEXT "Search results SQL DECLARE c1 CURSOR FOR PROCEDURE sqltables(:ownername, :tablename) ownername = 'Scott' SQL OPEN c1 WHILE SQLCODE EQ 0 DO SQL FETCH c1 INTO :tblowner, :tblname, :tbltype ... "Process fetched values DOEND
Example 22-4 Discovering Information About the Columns of a Relational Table
The following program fetches information about all columns in the employee
table owned by Scott
. Notice that NULL
(and not NA
) is used for the value of the third argument to SQLCOLUMNS
since it is processed by the relational manager, not Oracle OLAP.
DEFINE tblname TEXT "Search results DEFINE tblowner TEXT "Search results DEFINE colname TEXT "Search results DEFINE coltype TEXT "Search results DEFINE olaptype TEXT "Search results DEFINE length INTEGER "Search results DEFINE precision INTEGER "Search results DEFINE scale INTEGER "Search results DEFINE nullable TEXT "Search results SQL DECLARE c1 CURSOR FOR PROCEDURE sqlcolumns('Scott', - 'Employee', NULL) SQL OPEN c1 WHILE SQLCODE EQ 0 DO SQL FETCH c1 INTO :tblowner, :tblname, :colname, :coltype, - :olaptype, :length, :precision, :scale, :nullable ... "Process fetched values DOEND
The SQL EXECUTE command executes SQL statements that have been compiled using SQL PREPARE. Typically, the SQL statements that you precompile are statements that will be executed repeatedly, particularly those involving input host variables, such as INSERT
, UPDATE
, and DELETE
.
Syntax
SQL EXECUTE statement-name
Arguments
The name that you assigned to the executable code when you prepared it using SQL PREPARE.
Notes
The SQL PREPARE and SQL EXECUTE commands can only be used within the same DML program.
Examples
Example 22-5 Updating a Relational Table Using Analytic Workspace Data
The next example shows a simple update of a table using data stored in Oracle OLAP. The market dimension is limited to one value at a time in the FOR loop. The SQL phrase WHERE s.market=:market
specifies that the sales value in the row for that market is the value that is changed.
FOR market SQL UPDATE mkt SET sales=:mkt.sales WHERE s.market=:market
An UPDATE statement should be used in a SQL PREPARE command and executed in a FOR loop.
SQL PREPARE s2 FROM UPDATE mkt - SET sales=:mkt.sales WHERE s.market=:market FOR market DO SQL EXECUTE s2 IF SQLCODE NE 0 THEN BREAK DOEND
The SQL FETCH command retrieves and processes data specified by a named SQL cursor. SQL FETCH assigns the retrieved data to OLAP objects. When you include a THEN clause, SQL FETCH may perform processing on the retrieved data.
Syntax
SQL FETCH cursor [LOOP [loopcount]] -
INTO :targets... [THEN action-statements...]
where:
targets is one or more of the following:
[MATCH] dimension|surrogate
APPEND [position] dimension
ASSIGN surrogate
variable | qualified data reference | relation | composite
position is one of the following:
AFTER dimension-value
BEFORE dimension-value
FIRST
LAST
Arguments
The name of a declared and opened cursor.
Specifies that Oracle OLAP should implicitly loop over the rows obtained from a relational table. For each row, Oracle OLAP copies the data in individual fields to objects specified as target analytic workspace objects. When you include a LOOP clause, SQL FETCH will continue processing rows until it reaches the end of the active set specified by the cursor, or an error occurs, or loopcount is satisfied. In most cases, you should use the LOOP clause to improve the performance of SQL FETCH.
When you do not specify a LOOP clause and the cursor contains more than one row in its active set, you must code the SQL FETCH command within a WHILE loop. This loop must be based on the value of the SQLCODE option, which returns a nonzero value to indicate the end of the data or an error.
Optional integer argument to the LOOP keyword. Loopcount controls how SQL FETCH will loop over the rows from a relational table. Loopcount can be a literal value, a host variable, or NA
. When loopcount is less than or equal to zero, no looping occurs and no data is fetched.
When you specify a LOOP clause without a value for loopcount, SQL FETCH will continue reading rows and copying their contents to target analytic workspace objects until there are no more rows or an error occurs. Internally, each row is processed until SQLCODE is nonzero.
When you specify a literal value for loopcount, SQL FETCH will process the number of rows specified by loopcount or until SQLCODE is nonzero.
When you specify a variable for loopcount, it must be in the form of a host variable (preceded by a colon). This variable acts as both an input and an output host variable. The initial value of loopcount specifies the number of rows that SQL FETCH will attempt to process. Upon completion of the SQL FETCH, loopcount contains the number of rows actually processed.
When you specify NA
for loopcount, SQL FETCH will process rows until SQLCODE is nonzero. However, upon completion of the SQL FETCH, loopcount will contain the number of rows actually processed.
Identifies the analytic workspace objects in which you want to store data that is retrieved from a relational table. This list of target analytic workspace objects must correspond in number and data type with the list of table columns specified in the select-statement argument of the SQL DECLARE CURSOR command that declared cursor. A target can be a variable, a qualified data reference, a relation, a dimension, a composite, or a conjoint.
Important: The order in which you specify the target analytic workspace objects effects dimension status. For each dimension value, Oracle OLAP temporarily limits the status of the dimension to the fetched value. Values are assigned to subsequent analytic workspace objects according to this temporary status. See "Conjoints as Target Analytic Workspace Objects" and "Composites as Target Analytic Workspace Objects". |
A target must be preceded by a colon. When the target is a dimension, it can include the MATCH and APPEND keywords to specify dimension handling; in this case, the colon precedes the keywords.
Oracle OLAP does not perform dimension maintenance on the target dimension or surrogate. It uses the incoming values to align data that is being fetched into dimensioned objects. When a value from the relational database does not match any value in the dimension or surrogate, an error is signaled. (Default)
Oracle OLAP performs dimension maintenance on the target dimension, adding new values to the dimension. It uses both old and new dimension values to align data being fetched into dimensioned objects. By default, new values are added to the end of a dimension or surrogate. The position can also be used to control how dimension values are processed in action statements.
Any new values are added after dimension-value in the status list.
Any new values are added immediately before dimension-value in the status list.
Any new values are added to the beginning of the status list.
Any new values are added to the end of the status list.
Assigns the values to the specified surrogate.
You may optionally include a THEN clause to specify any number of action-statements to be performed each time a row of data is fetched and assigned to target analytic workspace objects. An action-statement can be one of the following:
assignment-statement
IF statement
SELECT-statement
ACROSS statement: action-statement
<action-statement-group>
Refer to the SQL IMPORT command for a complete description of the syntax of action-statements.
Notes
You use the SQL FETCH command in combination with other SQL commands to copy data from relational tables into analytic workspace objects as outlined in "Copying Relational Data into Analytic Workspace Objects".
For each dimension value, Oracle OLAP temporarily limits the status of the dimension to the fetched value. Values are assigned to subsequent analytic workspace objects according to this temporary status.
SQL FETCH and SQL IMPORT both copy data from relational tables into analytic workspace objects. Although SQL FETCH offers the most functionality, SQL IMPORT offers improved performance when copying large amounts of data from relational tables into analytic workspace objects.
You can use a conjoint dimension as a target analytic workspace object, but you must ensure that you select the same number of columns from the relational table as there are simple base dimensions. When Oracle OLAP executes a SQL FETCH command for a target that is a conjoint dimension, it uses the dimension order that was specified when the conjoint was defined.
You can specify analytic workspace objects for composites just as you would for dimensioned variables. For example, to fetch data into a variable var1
dimensioned by dim1
and dim2
, you would specify the following list of target analytic workspace objects.
:dim1 :dim2 :var1
To fetch data into a variable var2
dimensioned by a composite whose dimensions are dim1
and dim2
, you would specify the following list of target analytic workspace objects.
:dim1 :dim2 :var2
A null value in SQL is equivalent to an NA
value in Oracle OLAP, so null values fetched into target analytic workspace objects are given NA
values. Since Oracle OLAP handles null values in this way, the SQL command does not support INDICATOR
variables in the INTO clause of a SQL FETCH command. When fetching null values into a dimension, however, Oracle OLAP discards the values for the entire row.
Table 22-2, "RDBMS Data Type Conversion to OLAP DML Data Types" shows which Oracle RDBMS data types can be automatically converted into Oracle OLAP data types. You must explicitly convert or cast other data types in the SELECT statement within the SQL DECLARE CURSOR command.
You can use Boolean variables as input and target analytic workspace objects for OLAP SQL commands. In input host variables, Oracle OLAP treats Boolean values as integers with a value of 1
(TRUE
) or 0
(FALSE
).
As target analytic workspace objects, Boolean variables can receive values from any numeric (or bit) column in a relational table.
When fetching text data into a DATE variable, the current setting of the DATEORDER option is used to interpret the value. For example, a text value of 12-08-96
could be interpreted as December 8, 1996, or August 12, 1996, depending on the setting of DATEORDER.
You cannot transfer data with the following data types: RAW, LONG RAW, ROWID, UROWID, BLOB, and BFILE.
Examples
Example 22-6 Fetching Data From Relational Tables -- A Simple SQL FETCH
he following program fragment shows the basic steps of declaring and opening a cursor, and fetching the data. Relational data from the Prod_ID
and Prod_Name
columns of the Products
table are fetched into the prod
dimension and prod_label
variable. The variable prod_label
is dimensioned by prod
. Notice that the SQL FETCH command in this example does not include a LOOP clause; it therefore retrieves a single row of data each time it is called.
VARIABLE set_price SHORT set_price = 20 ... SQL DECLARE highprice CURSOR FOR SELECT Prod_ID, Prod_Name - FROM Products WHERE suggested_price > :set_price SQL OPEN highprice WHILE SQLCODE EQ 0 SQL FETCH highprice INTO :prod, :prod_label
Example 22-7 Fetching Data From Relational Tables with a THEN Clause
The following program fragment shows the SQL FETCH command from the previous example with the addition of the LOOP keyword and a THEN clause. Because of the LOOP keyword, this SQL FETCH command does not need to run within a WHILE loop. The action statement following the THEN keyword copies any product names stored in prod_label
that start with the letter A
into a multiline text variable called a_product
.
SQL FETCH highprice LOOP INTO :prod, :prod_label - THEN IF UPCASE(EXTCHARS(prod_label, 1, 1)) EQ 'a' - THEN a_product = JOINLINES(a_product prod_label)
Example 22-8 Populating with Relational Data While Maintaining a Conjoint Dimension
In this example, a conjoint dimension (named mpt
) is used as a target analytic workspace object. To populate a conjoint dimension, you must select values from the relational database for each of its base dimensions. Here, the three base dimensions are market
, product
, and time
. Therefore, the SELECT
statement specifies the three corresponding columns (Mktcode
, Prdcode
, and Percode
). The program assumes that the market
, product
, and time
dimensions are already populated with up-to-date values; Oracle OLAP does not update the base dimensions unless you explicitly specify them as target analytic workspace objects.
DEFINE mpt DIMENSION <market product time> DEFINE sql.mpt PROGRAM PROGRAM ... SQL DECLARE c1 CURSOR FOR - SELECT Mktcode, Prdcode, Percode FROM Sqldba.Data IF SQLCODE NE 0 THEN SIGNAL sqlerrm SQL OPEN c1 SQL FETCH c1 LOOP INTO :append mpt SQL CLOSE c1 ... END
Example 22-9 Populating Data While Maintaining Base and Conjoint Dimensions
To retrieve current values for the base and conjoint dimensions, or to retrieve the values for the first time, you can fetch the values for the base dimensions immediately before you fetch the values for the conjoint dimension. In the following example, the SQL DECLARE CURSOR and SQL FETCH commands have been edited to fetch both base and conjoint dimension values. Notice that the number of columns selected from the relational table must match the number of base dimensions fetched. There are six column specifications in the SELECT statement. The first three match the three base dimensions, and the last three match the conjoint dimension itself.
SQL DECLARE c1 CURSOR FOR - SELECT Mktcode, Prdcode, Percode, Mktcode, - Prdcode, Percode FROM Sqldba.Data ... SQL FETCH c1 LOOP INTO :APPEND market, :APPEND product, - :APPEND time, :APPEND mpt
Example 22-10 Populating Variables with Relational Table Data while Maintaining Dimensions
In the next example, variable dollars.mpt
is dimensioned by the conjoint mpt
, and its values are populated in the same SQL FETCH command with the dimension values. The SQL DECLARE CURSOR and SQL FETCH commands have been edited again with the new column and target analytic workspace object added.
DEFINE dollars.mpt DECIMAL <mpt> SQL DECLARE c1 CURSOR FOR - SELECT Mktcode, Prdcode, Percode, Mktcode, Prdcode, - Percode, Dollars FROM Sqldba.Data ... SQL FETCH c1 LOOP INTO :APPEND market, :APPEND product, - :APPEND time, :APPEND mpt, :DOLLARS.mpt
Example 22-11 Fetching Data into a Concat Dimension
Assume that a relational table has four columns of product data and that you decide to create a Product hierarchy with four levels in your analytic workspace to hold this data. The levels in the hierarchy (prod_id
, prod_subcategory
, prod_category
, and products_all
) map to columns in the products
tables. The lowest level of the hierarchy is prod_id
and the highest level is products_all
. There is also a column with supplier information in the table.
To hold the data in the analytic workspace you define a dimension was defined for each level of the Product hierarchy, a concat dimension for the hierarchy itself, and a child-parent relation between the values in the hierarchy. You also define a dimension for the supplier data and a relation that holds the relationship between suppliers and products with the following definitions.
DEFINE aw_prod_id DIMENSION NUMBER (6) DEFINE aw_prod_subcategory DIMENSION TEXT DEFINE aw_prod_category DIMENSION TEXT DEFINE aw_products_all DIMENSION TEXT DEFINE aw_products DIMENSION CONCAT (aw_products_all - aw_prod_category - aw_prod_subcategory - aw_prod_id) DEFINE aw_products.parents RELATION aw_products <aw_products> DEFINE aw_supplier_id DIMENSION NUMBER (6) DEFINE aw_prod_id.aw_supplier_id RELATION aw_supplier_id <aw_prod_id>
Assume that you write a program named get_products_hier
that consists of the following code.
' get_products_hier Program ALLSTAT " Fetch values into the products hierarchy SQL DECLARE grabprods CURSOR FOR SELECT prod_total, - prod_category, - prod_subcategory, - prod_id - FROM sh.products SQL OPEN grabprods SQL IMPORT grabprods INTO :APPEND aw_products_all - :APPEND aw_prod_category - :APPEND aw_prod_subcategory - :APPEND aw_prod_id SQL CLOSE grabprods SQL CLEANUP " Update the analytic workspace and make the updates permanent UPDATE COMMIT " Fetch values into supplier_id SQL DECLARE grabsupid CURSOR FOR SELECT supplier_id - FROM sh.products SQL OPEN grabsupid SQL IMPORT grabsupid INTO :APPEND aw_supplier_id SQL CLOSE grabsupid SQL CLEANUP " Update the analytic workspace and make the updates permanent UPDATE COMMIT " Populate self-relation for concat dimension " and relation between aw_prod_id and aw_supplier_id SQL DECLARE makerels CURSOR FOR SELECT prod_total, - prod_category, - prod_subcategory, - prod_id, - supplier_id - FROM sh.products SQL OPEN makerels SQL FETCH makerels LOOP INTO :MATCH aw_products_all - :MATCH aw_prod_category - :MATCH aw_prod_subcategory - :MATCH aw_prod_id - :MATCH aw_supplier_id - THEN aw_products.parents(aw_products aw_prod_id) - = aw_products(aw_prod_subcategory aw_prod_subcategory) - aw_products.parents(aw_products aw_prod_subcategory) - = aw_products(aw_prod_category aw_prod_category) - aw_products.parents(aw_products aw_prod_category) - = aw_products(aw_products_all aw_products_all) - aw_prod_id.aw_supplier_id = aw_supplier_id SQL CLOSE makerels SQL CLEANUP " Update the analytic workspace and make the updates permanent UPDATE COMMIT
The get_products_hier
program copies the data from the dimension tables into the base dimensions of the aw_products
concat dimension using SQL FETCH
commands with the APPEND
keyword. As the base dimensions of aw_products
are populated, Oracle OLAP automatically populates aw_products
, itself. As the THEN
clause of the SQL FETCH
command executes, Oracle OLAP fetches data into the child-parent self-relation for aw_products
. This program also populates the aw_supplier_id
dimension and its relation.
The SQL IMPORT command retrieves and processes data specified by an explicit SQL cursor. SQL IMPORT assigns the retrieved data to OLAP objects. When you include a THEN clause, SQL IMPORT may perform processing on the retrieved data SQL IMPORT is particularly effective in copying fact data from relational tables into analytic workspace variables.
Syntax
SQL IMPORT cursor INTO :targets... [THEN action-statements...]
where:
targets is one or more of the following:
[MATCH|MATCHSKIPERR [[position]] {dimension|surrogate|valueset|relation}
APPEND dimension
ASSIGN surrogate
{variable|relation|qualified data reference}
action-statements is one of the following:
assignment-statement
IF-statement
SELECT-statement
ACROSS-statement: action-statement
<action-statement-group>
Arguments
The name of a declared cursor.
Identifies the analytic workspace objects in which you want to store data that is retrieved from a relational table. This list of target analytic workspace objects must correspond in number and data type with the list of table columns specified in the select-statement argument of the SQL DECLARE CURSOR command that declared cursor. A target can be a variable, a qualified data reference, a relation, a dimension, or a composite.
Important: The order in which you specify the analytic workspace objects effects dimension status. For each dimension value, Oracle OLAP temporarily limits the status of the dimension to the fetched value. Values are assigned to subsequent analytic workspace objects according to this temporary status. |
Oracle OLAP does not copy values from the corresponding relational table column into the target dimension or surrogate. It merely uses the values to align data that is being fetched into dimensioned objects. When a value from the relational database does not match any value in the dimension, an error is signaled. (Default)
Oracle OLAP does not copy values from the corresponding relational table column into the target dimension or surrogate. It merely uses the values to align data that is being fetched into dimensioned objects. When a value from the relational database does not match any value in the dimension, the value is ignored and processing continues without signaling an error.
The one-based logical position of the value.
Oracle OLAP performs dimension maintenance on the target dimension, adding new values from the corresponding relational table column to the dimension. It uses both old and new dimension values to align data being fetched into dimensioned objects. New values are added to the end of a dimension.
Oracle OLAP assigns the corresponding relational value to the specified surrogate.
The name of the analytic workspace dimension.
The name of an analytic workspace surrogate.
The name of the analytic valueset.
The name of the analytic workspace relation.
The name of a variable.
A QDR is a qualifier that limits one or more of the dimensions of a variable or a relation to a single value. Oracle OLAP evaluates QDRs in a SQL IMPORT command, as follows:
When the QDR includes an expression, the expression is evaluated only once before the data is retrieved. In other words, the expression is, in essence, a constant.
When the QDR includes a relation, the values of the QDR vary depending on the status of the dimensions of that relation.
You may optionally include a THEN clause to specify any number of action-statements to be performed each time a row of data is imported and assigned to analytic workspace objects. Action statements may contain simple assignment statements, conditional assignment statements, and assignments across dimensions.
Action statements allow you to examine and manipulate the fetched data on a row-by-row basis. For example, you may want to specify temporary objects as analytic workspace objects and only update your permanent objects once you have performed certain actions on the row of fetched data. However, action statements do not have to reference the imported data. For example, one of your action statements might be an assignment statement that executes a user-defined function (that is, a program) that performs complex processing and then simply increments a counter.
A THEN clause can improve SQL loading performance by eliminating the need for postprocessing upon completion of a SQL IMPORT.
Note: The syntax of an action statement within SQL IMPORT is essentially the same as the syntax of an action statement within FILEREAD. Exceptions are in the syntax of an assignment statement and the use of the VALUE keyword. In SQL IMPORT action statements, assignments must be explicit; they must include a source, target, and equal sign. In FILEREAD action statements, assignments may be implicit and specify only the target. The VALUE keyword is supported in FILEREAD action statements, but not in SQL IMPORT action statements. When you have already specified action statements for use with FILEREAD, you can reuse the code with SQL IMPORT by simply adjusting the assignment statements and eliminating the VALUE keyword (if necessary). Most of the attributes listed in FILEREAD (with the exception of the attributes that control dimension processing) are not meaningful for SQL loading and are ignored when executing within SQL IMPORT.For best performance, within a THEN clause reference only the data within the imported row. |
In your list of action statements, be sure to process dimensions before variables. Oracle OLAP processes each action statement from left to right for each row in the relational table. When an action statement performs dimension processing, the resulting status remains in effect for subsequent action statements. When you do not first specify action statements that limit a variable's dimensions, Oracle OLAP uses the first value in status to target a cell in the variable. Unless you specify an ACROSS phrase, Oracle OLAP assigns a single value from a row to a single cell in an Oracle OLAP variable. By default, Oracle OLAP does not loop over a variable's dimensions when assigning data to the variable.
An assignment statement (SET) that assigns a value that is the result of an expression to an Oracle OLAP object.
An IF...THEN...ELSE statement that performs some action depending on whether a Boolean expression is TRUE
or FALSE
.
A SQL SELECT statement lets you perform some action based on the value of an expression. A SELECT statement has the following form.
SELECT select-expression
[WHEN expression1 action
[WHEN expression2 action . . .]
[ELSE action]
SELECT evaluates the SELECT expression and then sequentially compares the result with the WHEN expressions. When the first match is found, the associated action occurs. When no match is found, the ELSE action (if specified) occurs.
An ACROSS statement causes the following action statement to execute once for every value in status of the ACROSS dimension. When you want the looping to apply to more than one action statement, enclose the action statements in angle brackets. An ACROSS statement has the following form.
ACROSS dimension [limit]:
action-statement
limit temporarily change the status of dimension, as long as you are not in a FOR loop over dimension. The new status is in effect only for the duration of the SQL FETCH command. The format of limit is as follows.
[ADD|COMPLEMENT|KEEP|REMOVE|TO] limit-clause
To specify the temporary status, insert any of the LIMIT command keywords (the default is TO) along with an appropriate list of dimension values or related dimensions. You can use any valid LIMIT clause (see LIMIT command for further information). The following example limits month
to the last six values, no matter what the current status of month
is.
ACROSS month last 6: units
You can group several action statements together by enclosing them in angle brackets. An action-statement-group has the following form.
<action-statement1 -
[action-statement2 . . .]>
A typical use for action statement groups is after an ACROSS statement. With the angle bracket syntax, you can cause more than one action statement to execute for every value in status of the ACROSS dimension.
Notes
You use the SQL IMPORT command in combination with other SQL commands to copy data from relational tables into analytic workspace objects as outlined in "Copying Relational Data into Analytic Workspace Objects".
For each dimension value, Oracle OLAP temporarily limits the status of the dimension to the fetched value. Values are assigned to subsequent analytic workspace objects according to this temporary status.
SQL FETCH and SQL IMPORT both copy data from relational tables into analytic workspace objects. SQL IMPORT offers improved performance when copying large amounts of data from relational tables into analytic workspace objects.
For the syntax to use when declaring a cursor for use by SQL IMPORT see the notes for SQL DECLARE CURSOR.
Table 22-2, "RDBMS Data Type Conversion to OLAP DML Data Types" shows which Oracle RDBMS data types the SQL IMPORT command automatically converts into Oracle OLAP data types. You must explicitly convert or cast other data types in the SELECT statement within the SQL DECLARE CURSOR command.
Table 22-2 RDBMS Data Type Conversion to OLAP DML Data Types
Oracle RDBMS Data Type | OLAP DML Dimension Type | OLAP DML Variable Data Type |
---|---|---|
CHAR, NCHAR, NVARCHAR2, VARCHAR2 | TEXT [WIDTH n], ID, NTEXT | TEXT, NTEXT |
NUMBER | NUMBER, INTEGER, SHORTINTEGER, LONGINTEGER | NUMBER, INTEGER, BOOLEAN, SHORTINTEGER, LONGINTEGER, DECIMAL, SHORTDECIMAL |
CLOB (only within SQL FETCH and SQL SELECT statements) | TEXT | TEXT |
NCLOB (only within SQL FETCH and SQL SELECT statements) | NTEXT | NTEXT |
DATE | - | DATE, DATETIME |
You can use Boolean variables as input and target analytic workspace objects for OLAP SQL commands. In input host variables, Oracle OLAP treats Boolean values as integers with a value of 1 (TRUE) or 0 (FALSE).
As target analytic workspace objects, Boolean variables can receive values from any numeric (or bit) column in a relational table.
When importing text data into a DATE variable, the current setting of the DATEORDER option is used to interpret the value. For example, a text value of 12-08-96 could be interpreted as December 8, 1996, or August 12, 1996, depending on the setting of DATEORDER.
You cannot transfer data with the following data types: RAW, LONG RAW, ROWID, UROWID, BLOB, and BFILE.
Examples
Example 22-12 Simple Import
The following program fragment shows the basic steps of declaring a cursor and importing the data. Values from the Prod_ID
and Prod_Name
columns of the Products
relational table in the Sales -History (sh
) database are fetched into the prod_id
dimension and prod_label
analytic workspace variable. The prod_label
variable is dimensioned by prod_id
.
SQL DECLARE productcur CURSOR FOR SELECT Prod_ID, Prod_Name FROM sh.Products SQL OPEN productdur SQL IMPORT productcur INTO :prod_id, :prod_label SQL CLOSE productcur SQL CLEANUP
The SQL OPEN command activates an explicitly-declared SQL cursor. When the cursor is opened, SQL examines any input host variables used in the definition of the specified cursor, determines the cursor's result set, and leaves the cursor in the open state for use by SQL FETCH or SQL IMPORT. The cursor is positioned before the first row of the result set.
Syntax
SQL OPEN cursor
Arguments
The name of a cursor previously declared in the same program. You cannot use ampersand substitution.
Notes
You use the SQL OPEN command in combination with other SQL commands to copy data from relational tables into analytic workspace objects as outlined in "Copying Relational Data into Analytic Workspace Objects".
Examples
The following program fragment declares and opens a cursor named geolabels
.
SQL DECLARE geolabels CURSOR FOR - SELECT Store_ID, Store_Name, City FROM Stores IF SQLCODE NE 0 THEN SIGNAL dclerror 'SQLERRM' SQL OPEN geolabels IF SQLCODE NE 0 THEN SIGNAL operror 'SQLERRM'
The SQL PREPARE command precompiles a SQL statement for later execution using SQL EXECUTE. Typically, you use SQL PREPARE in programs to optimize the processing of SQL statements that will be executed repeatedly, particularly those involving input host variables, such as INSERT, UPDATE, and DELETE.
Syntax
SQL PREPARE statement-name FROM sql-statement [insert-options]
Arguments
A name that you assign to the executable code produced from sql-statement. You can redefine statement-name just by issuing another SQL PREPARE command.
The SQL statement that you want to precompile for more efficient execution. It cannot contain ampersand substitution or variables that are undefined when the program is compiled.
The following options are optional when sql-statement is an INSERT
statement:
DIRECT=YES|NO specifies if the insert is a direct-path INSERT
. This option must be the first option specified right aver the values phrase of the INSERT
statement. Setting this option to YES
specifies that the insert will be a direct-path INSERT
. Direct-path INSERT
enhances performance during INSERT
operations and is similar to the functionality of Oracle's direct-path loader utility, SQL*Loader. The default value is NO
which specifies a normal INSERT
.
NOLOG=YES|NO specifies if logging occurs. Setting this option to YES
specifies that the redo information is not recorded in the redo log files which makes load-time faster. The default value is NO
which specifies logging mode.
PARTITION=(sub)partition-name specifies that only the segments related to the named partition or subpartition are locked. When you specify this option, another session can insert data to unrelated segments in the same table. When you do not specify this option (the default), other sessions cannot insert data into the same table.
Notes
The SQL PREPARE and SQL EXECUTE commands can only be used within the same OLAP DML program.
When performing a direct-path INSERT
, data is written directly into data files, bypassing the buffer cache, free space in the existing data is not reused, and the inserted data is appended after existing data in the table
Direct-path INSERT
is subject to a number of restrictions. When executing a direct-path INSERT
using the OLAP DML, transactions in the session issuing the direct-path INSERT
must be committed for the INSERT
to execute successfully. (You can use the SQL or OLAP DML COMMIT to commit transactions.)
Additionally, the general restrictions that apply to using direct-path INSERT
in SQL apply to preparing a direct-pathINSERT
using the OLAP DML PREPARE command:
The target table cannot be index organized or clustered.
The target table cannot contain object type or LOB columns.
The target table cannot have any triggers or referential integrity constraints defined on it.
For more information on restrictions when using a direct-path INSERT, see the discussion of the INSERT
statement in Oracle Database SQL Reference.
Table 22-3, "Automatic Data Type Conversion During Direct-Path Insertion" shows the automatic data type conversion performed during direct-path insertion.
Table 22-3 Automatic Data Type Conversion During Direct-Path Insertion
Oracle RDBMS | Oracle OLAP DML |
---|---|
CHAR(n), VARCHAR(n) | TEXT |
LONG | TEXT with WIDE option |
CHAR(8), VARCHAR(8) | ID |
DATE | DATE |
NUMBER(x,x) | DECIMAL (SHORTDECIMAL) |
INTEGER (or NUMBER(38) | INTEGER (SHORTINTEGER) |
NUMBER(1) | BOOLEAN |
When inserting text data from Oracle OLAP into a column with a DATE data type, you must use the default date format of DD
MMM
YY
. You can use slashes (/
) or hyphens (-
) as separators, as well as spaces. When the data is in a different format, you can use the Oracle TO_DATE
function in the SQL INSERT
command.
To insert more than 2K bytes of text data from Oracle OLAP into a CLOB or NCLOB column, use the WIDE keyword before the name of the input host variable. When the input host variable is TEXT
, then the target data type is CLOB. When the input host variable is NTEXT, then the target data type is NCLOB.
The following is the syntax of an input host variable with the WIDE keyword. See Example 22-15, "Using the WIDE Keyword" for an example.
:WIDE input-host-variable
See Example 22-15, "Using the WIDE Keyword" for an example.
Note that the target table must conform to these guidelines:
Any number and combination of CLOB and NCLOB columns
No LONG columns
The RDBMS imposes some restrictions on large data types. Oracle OLAP will not signal an error when you violate these restrictions. However, you might get unexpected results. Refer to the Oracle Application Developer's Guide for restrictions on large data types.
You can calculate the number of characters that will be sent to the database from an input host variable by using the following formula.
NUMCHARS(variable) + 2 * (NUMLINES(variable) - 1)
For example, the following statement shows the number of characters that will be sent using bigvar
as the input host variable.
SHOW NUMCHARS(bigvar) + 2 * (NUMLINES(bigvar) -1)
This formula counts the extra carriage return and line feed characters that Oracle OLAP inserts between lines when passing the text to the database.
Examples
Example 22-13 Preparing a FOR Loop
To automatically add all the sales people from the salesperson
dimension to the relational table, you could write a program and put the SQL INSERT
command in a FOR loop.
FOR salesperson SQL INSERT INTO Sales VALUES (:Salesperson, :Dollars)
When a statement includes input host variables and will be executed repeatedly, such as in a FOR loop, you can make the statements more efficient by "preparing" the SQL statement first. The INSERT statement becomes part of a PREPARE statement.
SQL PREPARE s1 FROM INSERT INTO Sales VALUES - (:Salesperson, :Dollars) FOR Salesperson DO SQL EXECUTE s1 IF SQLCODE NE 0 THEN BREAK DOEND
Example 22-14 Updating a Table
The next example shows a simple update of a table using data stored in an analytic workspace. The market
dimension is limited to one value at a time in the FOR loop. The SQL phrase WHERE S.Market=:market
specifies that the sales value in the row for that market is the value that is changed.
FOR market SQL UPDATE Mkt SET Sales=:Mkt.Sales WHERE S.Market=:market
Like the INSERT statement in the previous example, an UPDATE
statement should be used in a PREPARE statement and executed in an ACROSS command or FOR loop.
SQL PREPARE s2 FROM UPDATE mkt - SET Sales=:mkt.sales WHERE s.market=:market ACROSS market DO 'SQL EXECUTE s1'
Example 22-15 Using the WIDE Keyword
In both of the following statements, WIDE
indicates that the target value is CLOB
when var1
is TEXT
, or NCLOB
when var1
is NTEXT
.
SQL INSERT INTO CLOB_TEST values (:dim1 :WIDE var1) SQL UPDATE CLOB_TEXT SET clob_col = :WIDE var1 WHERE key = 1
The SQL PROCEDURE command executes procedures stored in the RDBMS.
Note: You can also create SQL stored procedures using the OLAP DML. See: |
Syntax
SQL PROCEDURE procedure-name (parameters)
where parameters is one or more of the following, separated by commas:
Arguments
The name of the SQL stored procedure.
The name of a variable in the RDBMS.
A host variable name preceded by a colon. Host variables are OLAP DML expressions such as OLAP DML variables. See "SQL Terminology" and "Input Host Variables" for more information on host variables.
Notes
To create a stored procedure using the OLAP DML, issue an OLAP DML a SQL statement with a SQL CREATE PROCEDURE
statement as its argument. The syntax for coding CREATE PROCEDURE
as an argument within an OLAP DML a SQL statement is slightly different than the syntax for coding CREATE PROCEDURE
in SQL proper. When coded as an arguments to an OLAP DML statements, use a tilde (~
) instead of a semicolon as a terminator, and two colons instead of one in an assignment statement. See Example 22-16, "Creating a Stored Procedure".
A stored procedure called using an OLAP DML SQL PROCEDURE statement cannot contain output variables or transactions.
Examples
Example 22-16 Creating a Stored Procedure
The following example shows the syntax for creating a procedure named new_products
.
SQL CREATE OR REPLACE PROCEDURE new_products - (id CHAR, name CHAR, cost NUMBER) AS - price NUMBER~ - BEGIN - price ::= cost * 2.5~ - INSERT INTO products - VALUES(id, name, price)~ - END~
Example 22-17 Executing a Stored Procedure
The following FOR loop executes a SQL stored procedure named new_products
and inserts data stored in dimensions and variables into a relational table. In this example, prod
is an Oracle OLAP dimension, and labels.p
and cost.p
are variables dimensioned by prod
.
FOR prod DO SQL PROCEDURE new_products(:prod, :labels.p, :cost.p) IF SQLCODE NE 0 THEN BREAK DOEND
The SQL SELECT command uses an implicit cursor to copy data from relational tables into analytic workspace objects.
Syntax
SQL SELECT expressions FROM tables -
[WHERE predicates] [GROUP BY expressions] -
[ORDER BY expressions] [HAVING predicates] -
INTO :targets... [THEN action-statements...]
where:
targets is one or more of the following:
[MATCH] dimension|surrogate
APPEND [position] dimension
ASSIGN surrogate
variable|qualified data reference|relation|composite
position is one of the following:
Arguments
A SQL SELECT statement that identifies the data you want to associate with the cursor. For the syntax of an SQL SELECT statement, refer to the Oracle Database SQL Reference.
Identifies the analytic workspace objects in which you want to store data that is retrieved from a relational table. This list of target analytic workspace objects must correspond in number and data type with the list of table columns specified in the SELECT statement. A target can be a variable, a qualified data reference, a relation, a dimension, or a composite.
Important: The order in which you specify the analytic workspace objects effects dimension status. For each dimension value, Oracle OLAP temporarily limits the status of the dimension to the fetched value. Values are assigned to subsequent analytic workspace objects according to this temporary status. See "Conjoints as Target Analytic Workspace Objects" and "Composites as Target Analytic Workspace Objects". |
A target must be preceded by a colon. When the target is a dimension, it can include the MATCH and APPEND keywords to specify dimension handling; in this case, the colon precedes the keywords.
Oracle OLAP does not perform dimension maintenance on the target dimension or surrogate. It uses the incoming values to align data that is being fetched into dimensioned objects. When a value from the relational database does not match any value in the dimension or surrogate, an error is signaled. (Default)
Oracle OLAP performs dimension maintenance on the target dimension, adding new values to the dimension. It uses both old and new dimension values to align data being fetched into dimensioned objects. By default, new values are added to the end of a dimension or surrogate. The position can also be used to control how dimension values are processed in action statements.
Assigns the values to the specified surrogate.
You may optionally include a THEN clause to specify any number of action-statements to be performed each time a row of data is fetched and assigned to analytic workspace objects. An action-statement can be one of the following:
assignment-statement
IF statement
SELECT-statement
ACROSS statement: action-statement
<action-statement-group>
Refer to the SQL IMPORT command for a complete description of the syntax of action-statement.
Notes
You use the SQL SELECT command to copy data from relational tables into analytic workspace objects using an implicit cursor. You can also use copy the data using an explicit cursor using the OLAP DML commands outlined in "Copying Relational Data into Analytic Workspace Objects".
The following restrictions apply to the SQL SELECT command cannot contain ampersand substitution.
When copying values from relational tables into a multidimensional input variable, list the columns that correspond to the dimensions in an ORDER BY clause in the select-statement argument of the SQL SELECT command, with the slowest-varying dimension first. This will optimize performance.
The select-statement argument of a SQL SELECT command can include a WHERE clause. Since both OLAP DML syntax and SQL syntax allow you to use AND and OR, you should construct the clause clearly so that Oracle OLAP can identify the end of an input host variable. For example, the following WHERE clause is ambiguous, because the first host variable could be either ":MARKET AND PRDCODE" or simply ":MARKET."
... SELECT ... WHERE mktcode = :market AND prdcode = :product
Use the following construction instead.
... SELECT ... WHERE :market = mktcode AND :product = prdcode
You can also use parenthesis to clarify the syntax, particularly when using a SQL operator that is unknown in Oracle OLAP.
... SELECT ... WHERE (mktcode = :market) AND (prdcode LIKE :product)
Table 22-2, "RDBMS Data Type Conversion to OLAP DML Data Types" shows which Oracle RDBMS data types can be automatically converted into Oracle OLAP data types. You must explicitly convert or cast other data types in the SELECT statement.
Examples
Example 22-18 Simple select
For example, assume that there is a relational table named sales
with the following description.
PROD_ID NOT NULL NUMBER(6) CUST_ID NOT NULL NUMBER TIME_ID NOT NULL DATE CHANNEL_ID NOT NULL CHAR(1) PROMO_ID NOT NULL NUMBER(6) QUANTITY_SOLD NOT NULL NUMBER(3) AMOUNT_SOLD NOT NULL NUMBER(10,2)
Assume also that your analytic workspace contains the following definitions for corresponding analytic workspace objects.
DEFINE aw_prod_id DIMENSION NUMBER (6) DEFINE aw_cust_id DIMENSION NUMBER (6) DEFINE aw_date DIMENSION TEXT DEFINE aw_channel_id DIMENSION TEXT DEFINE aw_promo_id DIMENSION NUMBER (6) DEFINE aw_sales_dims COMPOSITE <aw_prod_id aw_cust_id - aw_channel_id aw_promo_id> DEFINE aw_sales_quantity_sold VARIABLE NUMBER (3) <aw_date aw_sales_dims - <aw_prod_id aw_cust_id aw_date aw_channel_id aw_promo_id>> DEFINE aw_sales_amount_sold VARIABLE NUMBER (10,2) <aw_date aw_sales_dims - <aw_prod_id aw_cust_id aw_date aw_channel_id aw_promo_id>>
To copy the data for product 415 from the sales
table into the analytic workspace objects, you execute the following statement in the OLAP worksheet.
SQL SELECT prod_id cust_id time_id channel_id promo_id quantity_sold -
amount_sold WHERE prod_id = 415 - INTO :aw_prod_id, :aw_cust_id, :aw_date, - :aw_channel_id, :aw_promo_id, :aw_sales_quantity_sold, :aw_sales_amount_sold