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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.
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.
Select a simple large object into a user-defined location

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
      - 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.
        Select a simple large object into a user-defined location
        Insert a simple large object into a user-defined location
        User-defined simple-large-object functions
        Informix® ESQL/C provides four transfer functions that you can redefine to handle a user-defined simple-large-object location.
      - 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.

Select a simple large object into a user-defined location

When your program selects a simple-large-object value, the Informix® ESQL/C libraries must receive the data from the database server and transfer it to the Informix® ESQL/C program. To do this, Informix® ESQL/C performs the following steps:

Before the transfer, Informix® ESQL/C calls the user-defined open function to initialize the user-defined location. The oflags argument of this open function is set to LOC_WONLY.
Informix® ESQL/C receives the simple-large-object value from the database server and puts it into a program buffer.
Informix® ESQL/C calls the user-defined write function to transfer the simple-large-object data from the program buffer to the user-defined location.
Informix® ESQL/C repeats steps 2 and 3 as many times as needed to transfer the entire simple-large-object value from the database server to the user-defined location.
After the transfer, Informix® ESQL/C performs the clean-up operations that the user-defined close function specifies.

To select a simple large object into a user-defined location, set loc_loctype to LOCUSER and set the loc_open, loc_write, and loc_close fields so they contain the addresses of appropriate user-defined open, write, and close functions.

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