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Introduction to Oracle Call Interface

This chapter provides introductory information to help you get started with Oracle Call Interface (OCI) for Windows.

This chapter contains these topics:

• What is the Oracle Call Interface?
  
  
• What is Included in the OCI Package?
  
  
• Oracle Directory Structure
  
  
• Sample Programs

  See Also: Oracle Call Interface Programmer's Guide for detailed information about OCI, including new features and function descriptions

What is the Oracle Call Interface?

The Oracle Call Interface (OCI) is an application programming interface (API) that allows applications written in C to interact with one or more Oracle Servers. OCI gives your programs the capability to perform the full range of database operations that are possible with Oracle9i database, including SQL statement processing and object manipulation.

What is Included in the OCI Package?

The Oracle Call Interface for Windows package includes:

• Oracle Call Interface
  
  
• Required Support Files (RSFs)
  
  
• Oracle Universal Installer
  
  
• Header files for compiling OCI applications
  
  
• Library files for linking OCI applications
  
  
• Sample programs for demonstrating how to build OCI applications

The OCI for Windows package includes the additional libraries required for linking your OCI programs on Windows NT, Windows 2000, and Windows 98.

Oracle Directory Structure

When you install the Oracle Call Interface for Windows, Oracle Universal Installer creates an ORACLE_BASE\ORACLE_HOME directory on the hard drive of your computer. The default Oracle home directory is C:\oracle\ora92.

The OCI files are located in the ORACLE_BASE\ORACLE_HOME directory, as are the library files needed to link and run OCI applications, and link with other Oracle for Windows NT products, such as Oracle Forms.

The ORACLE_BASE\ORACLE_HOME directory contains the following directories that are relevant to OCI:

Table 1-1 Oracle_Home Directories and contents  

Directory Name	Contents
\bin	Executable and help files
\oci	Oracle Call Interface directory for Windows files
\oci\include	Header files, such as oci.h and ociap.h
\oci\samples	Sample programs
\precomp\admin\ottcfg.cfg	Object Type Translator utility and default configuration file

Sample Programs

When OCI is installed, a set of sample programs and their corresponding project files are copied to the ORACLE_BASE\ORACLE_HOME\oci\samples subdirectory. Oracle Corporation recommends that you build and run these sample programs to verify that OCI has been successfully installed and to familiarize yourself with the steps involved in developing OCI applications.

To build a sample, run a batch file(make.bat)at the command prompt. For example, to build the cdemo1.c sample, enter the following command:

C:> make cdemo1

After you finish using these sample programs, you can delete them if you choose.

A sample OCI application specific to Windows platforms is included. cdemomt.c demonstrates OCI multithreading which is the thread safety feature of Oracle9i is also included on the Windows platforms. This sample program requires the emp table from the default database. The program spawns two simultaneous threads that attempt to insert different employee names with the same ID numbers. Thread synchronization is demonstrated.

ociucb.c should be compiled using ociucb.bat. This batch file creates a DLL and places it in the ORACLE_BASE\ORACLE_HOME\bin directory. To load user callback functions, set the environment/registry variable ORA_OCI_UCBPKG = OCIUCB.