Creating Parameters at Runtime
From InterBase
Go Up to Understanding Stored Procedure Parameters
If the name of the stored procedure is not specified in StoredProcName until runtime, no TParam objects will be automatically created for parameters and they must be created programmatically. This can be done using the TParam.Create method or the TParams.AddParam method.
For example, the InterBase stored procedure GET_EMP_PROJ, below, requires one input parameter (EMP_NO) and one output parameter (PROJ_ID).
CREATE PROCEDURE GET_EMP_PROJ (EMP_NO SMALLINT)
RETURNS (PROJ_ID CHAR(5))
AS
BEGIN
FOR SELECT PROJ_ID
FROM EMPLOYEE_PROJECT
WHERE EMP_NO = :EMP_NO
INTO :PROJ_ID
DO
SUSPEND;
END
The Delphi code to associate this stored procedure with a TIBStoredProc named StoredProc1 and create TParam objects for the two parameters using the TParam.Create method is:
var
P1, P2: TParam;
begin
{...}
with StoredProc1 do begin
StoredProcName := 'GET_EMP_PROJ';
Params.Clear;
P1 := TParam.Create(Params, ptInput);
P2 := TParam.Create(Params, ptOutput);
try
Params[0].Name := ‘EMP_NO’;
Params[1].Name := ‘PROJ_ID’;
ParamByname(‘EMP_NO’).AsSmallInt := 52;
ExecProc;
Edit1.Text := ParamByname(‘PROJ_ID’).AsString;
finally
P1.Free;
P2.Free;
end;
end;
{...}
end;