stored proc Output parameter in Firebird
lazarus / 16-Databases

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motaz · 2010-02-27 08:55

Hello
I get a NULL value in the output paramter (C) when calling this
FireBird procedure:

Code: [Select]ALTER PROCEDURE SUMMATION (
    A Integer,
    B Integer )
RETURNS (
    C Integer )
AS
BEGIN
  C = A + B;

END^

I'm using Zeos library to connect to Firebird 2.1:

Code: [Select]  ZStoredProc1.Params.Clear;
  ZStoredProc1.Params.Add;
  ZStoredProc1.Params[0].ParamType:= ptInput;
  ZStoredProc1.Params[0].DataType:= ftInteger;
  ZStoredProc1.Params[0].Name:= 'A';

  ZStoredProc1.Params.Add;
  ZStoredProc1.Params[1].ParamType:= ptInput;
  ZStoredProc1.Params[1].DataType:= ftInteger;
  ZStoredProc1.Params[1].Name:= 'B';

  ZStoredProc1.Params.Add;
  ZStoredProc1.Params[2].ParamType:= ptOutput;
  ZStoredProc1.Params[2].DataType:= ftInteger;
  ZStoredProc1.Params[2].Name:= 'C';

  ZStoredProc1.ParamByName('A').AsInteger:= 1;
  ZStoredProc1.ParamByName('B').AsInteger:= 2;
  ZStoredProc1.ExecSQL;
  ShowMessage(ZStoredProc1.ParamByName('C').AsString);


I'm using Lazarus 0.9.28.2 on Ubuntu
thanks

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fredycc · 2010-02-27 13:17

Hello motaz; test it:

create or alter procedure SUMMATION (
    A integer,
    B integer)
returns (
    C integer)
as
begin
  C = A + B;
  suspend;
end^

You need suspend for retun a value.

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JD · 2010-02-27 20:33

Results of stored procedures are passed back to the calling program by
the 'suspend' command.

Inserting 'suspend' on the line before 'end' will solve the problem.

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motaz · 2010-02-28 08:34

Yes, the problem solved, thatnks
but instead of calling the procedure by .ExecSql I use .Open to
execute and get the result