Oracle C++ Call Interface Programmer's Guide Release 2 (9.2) Part Number A96583-01 |
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OCCI Classes and Methods, 14 of 22
The Number
class handles limited-precision signed base 10 numbers. A Number
guarantees 38 decimal digits of precision. All positive numbers in the range displayed here can be represented to a full 38-digit precision:
10^-130
and
9.99999999999999999999999999999999999999*10^125
The range of representable negative numbers is symmetrical.
The number zero can be represented exactly. Also, Oracle numbers have representations for positive and negative infinity. These are generally used to indicate overflow.
The internal storage type is opaque and private. Scale is not preserved when Number
instances are created.
Number
does not support the concept of NaN and is not IEEE-754-85 compliant. Number
does support +Infinity and -Infinity.
There are several variants of syntax:
Default constructor.
Number(); Number(const Number &srcNum);
Translates a native long double into a Number
. The Number
is created using the precision of the platform-specific constant LDBL_DIG.
Number(long double val);
Translates a native double into a Number
. The Number
is created using the precision of the platform-specific constant DBL_DIG.
Number(double val);
Translates a native float into a Number
. The Number
is created using the precision of the platform-specific constant FLT_DIG.
Number(float val);
Translates a native long into a Number
.
Number(long val);
Translates a native int into a Number
.
Number(int val);
Translates a native short into a Number
.
Number(short val);
Translates a native char into a Number
.
Number(char val);
Translates a native signed char into a Number
.
Number(signed char val);
Translates an native unsigned long into a Number
.
Number(unsigned long val);
Translates a native unsigned int into a Number
.
Number(unsigned int val);
Translates a native unsigned short into a Number
.
Number(unsigned short val);
Translates the unsigned character array into a Number
.
Number(unsigned char val);
Objects from the Number
class can be used as standalone class objects in client side numerical computations. They can also be used to fetch from and set to the database.
The following code example demonstrates a Number
column value being retrieved from the database, a bind using a Number
object, and a comparison using a standalone Number
object:
/* Create a connection */ Environment *env = Environment::createEnvironment(Environment::DEFAULT); Connection *conn = env->createConnection(user, passwd, db); /* Create a statement and associate a select clause with it */ string sqlStmt = "SELECT department_id FROM DEPARTMENTS"; Statement *stmt = conn->createStatement(sqlStmt); /* Execute the statement to get a result set */ ResultSet *rset = stmt->executeQuery(); while(rset->next()) { Number deptId = rset->getNumber(1); /* Display the department id with the format string 9,999 */ cout << "Department Id" << deptId.toText(env, "9,999"); /* Use the number obtained as a bind value in the following query */ stmt->setSQL("SELECT * FROM EMPLOYEES WHERE department_id = :x"); stmt->setNumber(1, deptId); ResultSet *rset2 = stmt->executeQuery(); . . . } /* Using a Number object as a standalone and the operations on them */ /* Create a number to a double value */ double value = 2345.123; Number nu1 (value); /* Some common Number methods */ Number abs = nu1.abs(); /* absolute value */ Number sqrt = nu1.squareroot(); /* square root */ /* Cast operators can be used */ long lnum = (long) nu1; /* Unary increment/decrement prefix/postfix notation */ nu1++; --nu1; /* Arithmetic operations */ Number nu2(nu1); /* Assignment operators */ Number nu3; nu3 = nu2; nu2 = nu2 + 5.89; Number nu4; nu4 = nu1 + nu2; /* Comparison operators */ if(nu1>nu2) . . . else if(nu1 == nu2) . . .
This method returns the absolute value of the Number
object.
const Number abs() const;
This method returns the arccosine of the Number
object.
const Numberconst Number arcCos() const;
This method returns the arcsine of the Number
object.
const Number arcSin() const;
This method returns the arctangent of the Number
object.
const Number arcTan() const;
This method returns the arctangent of the Number
object with the parameter specified. It returns atan2 ( y,x) where y is the parameter specified and x is the current number object.
const Number arcTan2(const Number &val) const
Number parameter y to the arcTangent function atan2(y,x) .
This method returns the smallest integer that is greater than or equal to the Number
object.
const Number ceil() const;
This method returns the cosine of the Number
object.
const Number cos() const;
This method returns the natural exponential of the Number
object.
const Number exp() const;
This method returns the largest integer that is less than or equal to the Number
object.
const Number floor() const;
This method returns a Number
object represented by the byte string specified.
void fromBytes(const Bytes &s);
A byte string.
This method returns a Number
object derived from a string value.
void fromText(const Environment *envp, const string &number, const string &fmt, const string &nlsParam = "");
The OCCI environment.
The number string to be converted to a Number
object.
Format string.
The nls parameters string. If nlsParam
is specified, this determines the nls parameters to be used for the conversion. If nlsParam
is not specified, the nls parameters are picked up from envp
.
This method returns the hypercosine of the Number
object.
const Number hypCos() const;
This method returns the hypersine of the Number
object.
const Number hypSin() const;
This method returns the hypertangent of the Number
object.
const Number hypTan() const;
This method returns a Number
whose value is the number object raised to the power of the value specified.
const Number intPower(int val) const;
Integer to whose power the number is raised.
This method tests whether the Number
object is null. If the Number
object is null, then true is returned; otherwise, false is returned.
bool isNull() const;
This method returns the natural logorithm of the Number
object.
const Number ln() const;
This method returns the logorithm of the Number
object with the base provided by the parameter specified.
const Number log(const Number &val) const;
The base to be used in the logorithm calculation.
Unary operator++()
. This method returns the Number
object incremented by 1. This is a prefix operator.
Number& operator++();
Unary operator++().
This method returns the Number
object incremented by the integer specified. This is a postfix operator.
const Number operator++(int);
Unary operator--()
. This method returns the Number
object decremented by 1. This is a prefix operator.
Number& operator--();
Unary operator--()
. This method returns the Number
object decremented by the integer specified. This is a postfix operator.
const Number operator--(int);
This method returns the product of the parameters specified.
Number operator*(const Number &a, const Number &b);
Numbers to be multiplied.
This method returns the quotient of the parameters specified.
Number operator/(const Number ÷nd, const Number &divisor);
The number to be divided.
The number to divide by.
This method returns the remainder of the division of the parameters specified.
Number operator%(const Number &a, const Number &b);
Numbers which are operands in the modulo operation.
This method returns the sum of the parameters specified.
Number operator+(const Number &a, const Number &b);
Numbers which are added.
Unary operator-()
. This method returns the negated value of the Number
object.
const Number operator-();
This method returns the difference between the parameters specified.
Number operator-(const Number &subtrahend, const Number &subtractor);
The number to be reduced.
The number to be subtracted.
This method checks whether the first parameter specified is less than the second parameter specified. If the first parameter is less than the second parameter, then true is returned; otherwise, false is returned. If either parameter is equal to infinity, then false is returned.
bool operator<(const Number &a, const Number &b);
Numbers which are compared .
This method checks whether the first parameter specified is less than or equal to the second parameter specified. If the first parameter is less than or equal to the second parameter, then true is returned; otherwise, false is returned. If either parameter
is equal to infinity, then false is returned.
bool operator<=(const Number &a, const Number &b);
Numbers which are compared.
This method checks whether the first parameter specified is greater than the second parameter specified. If the first parameter is greater than the second parameter, then true is returned; otherwise, false is returned. If either parameter is equal to infinity, then false is returned.
bool operator>(const Number &a, const Number &b);
Numbers which are compared .
This method checks whether the first parameter specified is greater than or equal to the second parameter specified. If the first parameter is greater than or equal to the second parameter, then true is returned; otherwise, false is returned. If either parameter is equal to infinity, then false is returned.
bool operator>=(const Number &a, const Number &b);
Numbers which are compared.
This method checks whether the parameters specified are equal. If the parameters are equal, then true is returned; otherwise, false is returned. If either parameter is equal to +infinity or -infinity, then false is returned.
bool operator==(const Number &a, const Number &b);
Numbers which are compared.
This method checks whether the first parameter specified is equal to the second parameter specified. If the parameters are not equal, true is returned; otherwise, false is returned.
bool operator!=(const Number &a, const Number &b);
Numbers which are compared.
This method assigns the value of the parameter specified to the Number
object.
Number& operator=(const Number &a);
The number to be assigned.
This method multiplies the Number
object by the parameter specified, and assigns the product to the Number
object.
Number& operator*=(const Number &a);
A parameter of type Number
.
This method divides the Number
object by the parameter specified, and assigns the quotient to the Number
object.
Number& operator/=(const Number &a);
A parameter of type Number
.
This method divides the Number
object by the parameter specified, and assigns the remainder to the Number
object.
Number& operator%=(const Number &a);
A parameter of type Number
.
This method adds the Number object and the parameter specified, and assigns the sum to the Number
object.
Number& operator+=(const Number &a);
A parameter of type Number
.
This method subtracts the parameter specified from the Number
object, and assigns the difference to the Number
object.
Number& operator-=(const Number &a);
A parameter of type Number
.
This method returns the value of the Number object converted to a native char.
operator char() const;
This method returns the value of the Number object converted to a native signed char.
operator signed char() const;
This method returns the value of the Number
object converted to a native double.
operator double() const;
This method returns the value of the Number
object converted to a native float.
operator float() const;
This method returns the value of the Number
object converted to a native int.
operator int()const;
This method returns the value of the Number
object converted to a native long.
operator long() const;
This method returns the value of the Number
object converted to a native long double.
operator long double() const;
This method returns the value of the Number
object converted to a native short integer.
operator short() const;
This method returns the value of the Number
object converted to a native unsigned char.
operator unsigned char() const;
This method returns the value of the Number
object converted to a native unsigned integer.
operator unsigned int() const;
This method returns the value of the Number
object converted to a native unsigned long.
operator unsigned long() const;
This method returns the value of the Number
object converted to a native unsigned short integer.
operator unsigned short() const;
This method returns the value of the Number
object raised to the power of the value provided by the parameter specified.
const Number power(const Number &val) const;
The number to whose power this number has to be raised.
This method returns the value of the Number
object rounded to the digits of precision provided by the parameter specified.
const Number prec(int digits) const;
The number of digits of precision.
This method returns the value of the Number
object rounded to the decimal place provided by the parameter specified.
const Number round(int decplace) const;
The number of digits to the right of the decimal point.
This method sets the value of the Number
object to null.
void setNull();
This method returns the Number
object multiplied by 10 to the power provided by the parameter specified.
const Number shift(int val) const;
An integer value.
This method returns the sign of the value of the Number
object. If the Number
object is negative, then -1 is returned. If the Number
object is equal to 0, then 0 is returned. If the Number
object is positive, then 1 is returned.
const int sign() const;
This method returns the sin of the Number
object.
const Number sin();
This method returns the square root of the Number
object.
const Number squareroot() const;
This method returns the tangent of the Number
object.
const Number tan() const;
This method converts the Number
object into a Bytes
object. The bytes representation is assumed to be in length excluded format, that is, the Byte.length()
method gives the length of valid bytes and the 0th byte is the exponent byte.
Bytes toBytes() const;
This method converts the Number
object to a formatted string based on the parameters specified.
See Also:
Oracle9i SQL Reference for information on TO_CHAR. |
string toText(const Environment *envp, const string &fmt, const string &nlsParam = "") const;
The OCCI environment.
The format string.
The nls parameters string. If nlsParam
is specified, this determines the nls parameters to be used for the conversion. If nlsParam
is not specified, the nls parameters are picked up from envp
.
This method returns the Number
object truncated at the number of decimal places provided by the parameter specified.
const Number trunc(int decplace) const;
The number of places to the right of the decimal place at which the value is to be truncated.
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