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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?
Character and string data types
These topics explain how to use character data types in the Informix® ESQL/C program.
Character data types
Informix® ESQL/C supports five data types that can hold character data that you retrieve from and send to the database.
The lvarchar data type
The lvarchar data type is the Informix® ESQL/C data type that holds character data of varying lengths.

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.
      - Character data types
        Informix® ESQL/C supports five data types that can hold character data that you retrieve from and send to the database.
        The char data type
        The char data type is the C data type that holds character data.
        The fixchar data type
        The fixchar data type is the Informix® ESQL/C data type that holds character data that does not append a null terminator.
        The string data type
        The string data type is the Informix® ESQL/C data type that holds character data that is null terminated and does not contain trailing blanks.
        The varchar data type
        The varchar data type is the Informix® ESQL/C data type that holds character data of varying lengths.
        The lvarchar data type
        The lvarchar data type is the Informix® ESQL/C data type that holds character data of varying lengths.
        The lvarchar keyword syntax
        To declare an lvarchar host variable for a character column (CHAR, VARCHAR, or LVARCHAR), use the lvarchar keyword as the variable data type.
        A lvarchar host variable of a fixed size
        The lvarchar pointer host variable
      - Fetch and insert character data types
      - Character and string library functions
    - 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.
    - 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.

The lvarchar data type

The lvarchar data type is the Informix® ESQL/C data type that holds character data of varying lengths.

The lvarchar data type is implemented as a variable length user-defined type that is similar to the varchar data type except that it can support strings of greater than 256 bytes and has the following two uses:

To hold a value for an LVARCHAR column in the database.
When an application reads a value from an LVARCHAR column into a host variable of the lvarchar data type, Informix® ESQL/C preserves any trailing blanks and terminates the array with a null character. The behavior is the same if an application reads a value from a VARCHAR column into a host variable of the lvarchar data type.
To represent the string or external format of opaque data types.

Important: You cannot retrieve or store smart large objects (CLOB or BLOB data types) from or to an lvarchar host variable.