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Client APIs and toolsYou can use the HCL OneDB™ implementation of client APIs to develop applications for HCL OneDB™ database servers.
ESQL/C GuideThe HCL OneDB™ ESQL/C Programmer's Manual explains how to use , the HCL OneDB™ implementation of Embedded Structured Query Language (SQL) for C (ESQL/C), to create client applications with database-management capabilities.
Dynamic SQL
A system-descriptor areaA 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.
Manage a system-descriptor area
Allocate memory for a system-descriptor areaTo allocate memory for a system-descriptor area, use the ALLOCATE DESCRIPTOR statement.

Allocate memory for a system-descriptor area

To allocate memory for a system-descriptor area, use the ALLOCATE DESCRIPTOR statement.

The ALLOCATE DESCRIPTOR statement performs the following tasks:

It assigns the specified descriptor name to identify this region of memory. This name is an identifier that must be provided in all the SQL statements listed in SQL statements that can be used to manipulate a system-descriptor area to designate the system descriptor on which to take action.
It allocates item descriptors. By default, it allocates 100 item descriptors in the system-descriptor area. You can change this default with the WITH MAX clause.
It initializes the COUNT field in the system-descriptor area to the number of item descriptors allocated.

Important: ALLOCATE DESCRIPTOR does not allocate memory for column data (DATA field). This memory is allocated by the DESCRIBE statement on an as-needed basis. For more information, see the next section.