Data Language Interface: Difference between revisions

Revision as of 18:08, 26 May 2009

Revision as of 08:01, 15 June 2009

Line 10:

When accessing a database segment the application program also uses an ''SSA'' (Segment Search Argument) as a parameter, to specify the segment or segments that it needs. This would typically contain the segment type required, and the contents of any key fields.

For all languages except [[PL/I]], first parameter in a call is the ''Function Code'' — a four character field, examples being: “GU  ” (Get Unique), “GN  ” (Get Next), “REPL” (Replace), and “ISRT” (Insert). With PL/1I, due to the way this language does not mark the last parameter with a '1' in bit 0, the first parameter must instead be a fullword (Fixed Bin(31)) containing the number of following parameters.

A typical call from a COBOL program might be . . . CALL “CBLTDLI” USING GU, Stores-Database-PCB, Stores-Segment-Area, Stores-Root-SSA. The program would then automatically wait till the requested data was retrieved and placed in the Segment-Area. The status code contained within the PCB would be updated with either blanks (if all went well) or some informational or error code.

A typical call from a PL/1I program might be . . . CALL PLITDLI(FOUR, GU, Stores-Database-PCB, Stores-Segment-Area, Stores-Root-SSA);

==External links==