Entering content frame

 Structure of the Descriptor 

This table describes the structure of the descriptor (the data structure sqlda) that you can use in dynamic SQL statements with parameters in the SQL mode INTERNAL.

The C/C++ precompiler also supports ORACLE sqlda data structures (see Compatibility with Other Database Systems).

sqldaid

Contains the character string sqlda for finding the structure in a memory dump

sqlmax

Maximum number of sqlvar entries

The C/C++ precompiler specifies the constant sqlmax = 300 for this value, however, you can change it.

sqln

Number of sqlvar entries currently allocated

sqld

Number of output parameters used in the SQL statement

Any parameters that can be both input and output parameters are also counted as output parameters.

sqlvar

array [sqlmax] of sqlvar entries

For each parameter, an entry sqlvar [i] is generated according to the order in which the parameter appears in the SQL statement. This entry contains information on the data type and the length of the addressed table column.

All constants used in the descriptor are declared in the header file cpc.h.

If you do not want to use the standard descriptor, you can declare the descriptor <descriptor_name> as a variable of the type sqldatype or struct sqlda (in SQL mode ORACLE, SQLDA only). However, the descriptor must always have the same type within a program.

 

Leaving content frame