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Client APIs and tools
You can use the HCL Informix® implementation of client APIs to develop applications for Informix database servers.
ESQL/C Guide
The Informix® ESQL/C Programmer's Manual explains how to use Informix ESQL/C, the Informix implementation of Embedded Structured Query Language (SQL) for C (ESQL/C), to create client applications with database-management capabilities.
Dynamic SQL
Using dynamic SQL

Client APIs and tools
You can use the HCL Informix® implementation of client APIs to develop applications for Informix database servers.
- Change Data Capture API Programmer's Guide
  The Informix® Change Data Capture API Programmer's Guide describes how to program applications to process changed data from HCL Informix databases using the Informix Change Data Capture API.
- Embedded SQLJ for HCL Informix®
  The Informix® Embedded SQLJ User's Guide contains information about using Informix Embedded SQLJ.
- ESQL/C Guide
  The Informix® ESQL/C Programmer's Manual explains how to use Informix ESQL/C, the Informix implementation of Embedded Structured Query Language (SQL) for C (ESQL/C), to create client applications with database-management capabilities.
  - What is Informix® ESQL/C?
  - Database server communication
  - Dynamic SQL
    - Using dynamic SQL
      - Execute dynamic SQL
      - A database cursor
        A database cursor is an identifier associated with a group of rows. It is, in a sense, a pointer to the current row in a buffer.
      - The collect.ec program
      - Optimize OPEN, FETCH, and CLOSE
      - Using OPTOFC and Deferred-PREPARE together
        To achieve the most optimized number of messages between the client application and the database server, use the Optimize OPEN, FETCH, CLOSE feature, and the Deferred-PREPARE feature together.
      - SQL statements that are known at compile time
      - SQL statements that are not known at compile time
        An SQL statement that is not known at compile time is usually one that the user enters in an interactive application.
    - Determine SQL statements
      If you do not know until run time what SQL statement to execute, you can dynamically determine that statement with the DESCRIBE statement and use a dynamic-management structure to hold any values that the statement sends to or receives from the database server.
    - A system-descriptor area
      A system-descriptor area is a dynamic-management structure that can hold data that a prepared statement either returns from or sends to the database server. A system-descriptor area conforms to X/Open standards.
    - An sqlda structure
      An sqlda structure is a dynamic-management structure that can hold data that is either returned from or sent to the database server by a prepared statement. It is a C structure defined in the sqlda.h header file.
  - Appendixes
    This section contains additional reference information.
- GLS User's Guide
  The Informix® GLS User's Guide describes the Global Language Support (GLS) feature available in Informix products.
- API
  The Informix® GLS API Programmer's Guide describes the global language support (GLS) application programming interface (API) available in Informix ESQL/C and HCL Informix DataBlade® modules.
- Informix® Object Interface for C++ Guide
  The Informix® Object Interface for C++ Programmer's Guide describes how to develop HCL Informix client applications by using the object-oriented C++ programming language.
- Informix® ODBC Driver Guide
  The Informix® ODBC Driver Programmer's Manual serves as a user guide and reference for Informix ODBC Driver, which is the Informix implementation of the Microsoft™ Open Database Connectivity (ODBC) interface, Version 3.0.
- .NET provider options
  The Data Server Provider for .NET DB2® provider option is the preferred Informix® provider for developing new applications.
- Informix® JDBC Driver Guide
  The Informix® JDBC Driver Programmer's Guide describes how to install, load, and use Informix JDBC Driver to connect to the Informix database from within a Java™ application or applet.
- Informix International Language Supplement (ILS) User Guide
  These topics include information about the translated user interface files for Informix® UNIX™ products, locales, and code set conversion tables
- Informix® OLE DB Provider Guide
  The Informix® OLE DB Provider Programmer's Guide describes the software requirements for using Informix OLE DB Provider, show how to install and configure the provider for your use, and explain how to use Informix OLE DB Provider to enable client applications, such as ActiveX Data Object (ADO) applications and web pages, to access data on the Informix server.

Using dynamic SQL

A static SQL statement is one for which all the information is known at compile time. For example, the following SELECT statement is a static SQL statement because all information needed for its execution is present at compile time.

EXEC SQL select company into :cmp_name from customer where customer_num 
= 101;

However, in some applications the programmer does not know the contents, or possibly even the types, of SQL statements that the program needs to execute. For example, a program might prompt the user to enter a select statement, so that the programmer has no idea what columns are accessed when the program is run. Such applications require dynamic SQL. Dynamic SQL allows the Informix® ESQL/C program to build an SQL statement at run time, so that the contents of the statement can be determined by user input.

These topics describe the following dynamic SQL information:

How to execute a dynamic SQL statement, the SQL statements to use, and the types of statements that you can execute dynamically
How to execute SQL statements when you know most of the information about the statement at compile time