OCIDefineDynamic()

Purpose

This call is used to set the additional attributes required if the OCI_DYNAMIC_FETCH mode was selected in OCIDefineByPos().

Syntax

sword OCIDefineDynamic ( OCIDefine   *defnp,
                         OCIError    *errhp,
                         dvoid       *octxp, 
                         OCICallbackDefine       (ocbfp)(/*_
                                  dvoid          *octxp,
                                  OCIDefine      *defnp,
                                  ub4            iter, 
                                  dvoid          **bufpp,
                                  ub4            **alenpp,
                                  ub1            *piecep,
                                  dvoid          **indpp,
                                  ub2            **rcodep _*/)  );

Parameters

defnp (IN/OUT)

The handle to a define structure returned by a call to OCIDefineByPos().

errhp (IN/OUT)

An error handle you can pass to OCIErrorGet() for diagnostic information in the event of an error.

octxp (IN)

Points to a context for the callback function.

ocbfp (IN)

Points to a callback function. This is invoked at runtime to get a pointer to the buffer into which the fetched data or a piece of it will be retrieved. The callback also specifies the indicator, the return code and the lengths of the data piece and indicator.

The callback parameters are listed below:

octxp (IN/OUT)
A context pointer passed as an argument to all the callback functions.

defnp (IN)
The define handle.

iter (IN)
Which row of this current fetch; 0-based.

bufpp (OUT)
Returns a pointer to a buffer to store the column value, that is, *bufpp points to some appropriate storage for the column value.

alenpp (IN/OUT)
Used by the application to set the size of the storage it is providing in *bufpp. After data is fetched into the buffer, alenpp indicates the actual size of the data in bytes.

piecep (IN/OUT)
Returns a piece value from the callback (application) to Oracle, as follows:

• IN - The value can be OCI_ONE_PIECE or OCI_NEXT_PIECE.
• OUT - Depends on the IN value:

  If IN value is OCI_ONE_PIECE, then OUT value can be OCI_ONE_PIECE or OCI_FIRST_PIECE

  If IN value is OCI_NEXT_PIECE then OUT value can be OCI_NEXT_PIECE or OCI_LAST_PIECE

indpp (IN)
Indicator variable pointer

rcodep (IN)
Return code variable pointer

Comments

This call is used to set the additional attributes required if the OCI_DYNAMIC_FETCH mode has been selected in a call to OCIDefineByPos(). If OCI_DYNAMIC_FETCH mode was selected, and the call to OCIDefineDynamic() is skipped, then the application can fetch data piecewise using OCI calls (OCIStmtGetPieceInfo() and OCIStmtSetPieceInfo()). For more information about OCI_DYNAMIC_FETCH mode, see the section "Runtime Data Allocation and Piecewise Operations".

Related Functions

OCIDefineByPos()