Data area
The third fullword in the parameter list is the address of a fullword that contains the address of a data area.
A data area consists of the actual data involved in the request. If you are retrieving information from a database, EQQYCOM places the record in this area and provides its address in the fullword whose address is in the parameter list.
Note: EQQYCOM might use the same piece of data area storage
for successive data retrieval requests, overwriting the storage area
used for the previous request each time. Therefore, your program must
copy the information to its own storage area if it must be kept during
later retrieval requests.
If you are writing information to a database, your program must build its own data area and provide its address in the fullword whose address is in the parameter list.
Attention: When the data area is not used, the data area address in
the parameter list must be set to hexadecimal zero; failure to do
so might cause unpredictable results. Some programming languages might
require special coding to achieve this task; for example, in PL/I
programs, use the SYSNULL built-in function.
The data area consists of a header, which describes the structure of the data record, and the data itself. For a detailed description, see Data area description and format.