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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
Determine SQL statementsIf 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.
Dynamic-management structureIf you do not know the number or data types of values sent to or received from the database server, use a dynamic-management structure. A dynamic-management structure allows you to pass a variable-length list of data to the database server, or receive a variable-length list of data from it.
A system-descriptor areaA system-descriptor area is an area of memory declared by to hold data either returned from or sent by a prepared statement. It is the dynamic-management structure that conforms to the X/Open standards.

A system-descriptor area

A system-descriptor area is an area of memory declared by to hold data either returned from or sent by a prepared statement. It is the dynamic-management structure that conforms to the X/Open standards.

A system-descriptor area has two parts:

A fixed-size portion is made up of the COUNT field. This field contains the number of columns described in the system-descriptor area.
A variable-length portion contains an item descriptor for each value in the system-descriptor area. Each item descriptor is a fixed-size structure.

The following figure shows what a system-descriptor area looks like for two values.

Figure 1: Schematic that shows system-descriptor area for two values

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