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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.
What is Informix® ESQL/C?
Simple large objects
A simple large object is a large object that is stored in a blobspace on disk and is not recoverable.
Locate simple large objects in memory
Allocate the memory buffer
When your program selects simple-large-object data into memory, Informix® ESQL/C uses a memory buffer.

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?
    - Informix® ESQL/C programming
    - Compile programs
    - Informix® ESQL/C data types
      These topics contain information about the correspondence between SQL and C data types and how to handle data types in the Informix® ESQL/C program.
    - Character and string data types
      These topics explain how to use character data types in the Informix® ESQL/C program.
    - Numeric data types
    - Time data types
      These topics explain how to use date, datetime, and interval data types in the Informix® ESQL/C program.
    - Simple large objects
      A simple large object is a large object that is stored in a blobspace on disk and is not recoverable.
      - Choose a large-object data type
        If you use HCL Informix® as your database server, you can choose between using simple large objects or smart large objects.
      - Programming with simple large objects
        Informix® ESQL/C supports SQL simple large objects and the data types TEXT and BYTE with the loc_t data type.
      - Locate simple large objects in memory
        Allocate the memory buffer
        When your program selects simple-large-object data into memory, Informix® ESQL/C uses a memory buffer.
        A memory buffer that the ESQL/C libraries allocate
        A memory buffer that the program allocates
        Select a simple large object into memory
        The getcd_me sample program from the demo directory shows how to select a simple large object from the database into memory.
        Insert a simple large object from memory
        The updcd_me sample program from the demo directory shows how to insert a simple large object from memory into the database.
      - Locate simple large objects in files
        You can locate simple-large-object data in the open or named types of files.
      - User-defined simple-large-object locations
        You can create your own versions of the loc_open(), loc_read(), loc_write(), and loc_close() functions to define your own location for simple-large-object data.
      - The dispcat_pic program
        The dispcat_pic program uses the Informix® ESQL/C ifx_loc_t locator structure to retrieve two simple-large-object columns. The program retrieves the cat_descr TEXT simple-large-object column and the cat_picture BYTE column from the catalog table of the stores7 demonstration database.
    - Smart large objects
      A smart large object is a data type that stores large, non-relational data objects such as images, sound clips, documents, graphics, maps and other large objects, and allows you to perform read, write, and seek operations on those objects.
    - Complex data types
      These topics explain how to use collection and row data types in the Informix® ESQL/C program.
    - Opaque data types
      These topics explain how to use the lvarchar, fixed binary, and var binary data types to access an opaque data type from the Informix® ESQL/C program. Use these Informix ESQL/C data types to represent an opaque data type as it is transferred to and from Informix.
  - Database server communication
  - Dynamic SQL
  - 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.

Allocate the memory buffer

When your program selects simple-large-object data into memory, Informix® ESQL/C uses a memory buffer.

Before your program fetches TEXT or BYTE data, you must set the loc_bufsize (lc_union.lc_mem.lc_bufsize) field as follows to indicate how Informix® ESQL/C allocates this memory buffer:

If you set the loc_bufsize to -1, Informix® ESQL/C allocates the memory buffer to hold the simple-large-object data.
If you set the loc_bufsize to a value that is not -1, Informix® ESQL/C assumes that the program handles memory-buffer allocation and deallocation.

Important: When you locate simple large objects in memory, you must always set loc_mflags (lc_union.lc_mem.lc_mflags) and loc_oflags to 0 initially.