Dynamic SQL with pgsql, how to?

Hi,

I need to write some dynamic SQL in pgsql.

I have to do something like this:

[code=SQL Server]
SET @STRINGN = @STRINGN + ' AND A.' + @CAMPOFECINI + ' IN (SELECT
MAX(B.' + @CAMPOFECINI + ')
FROM ' + @TABLA + ' B
WHERE B.ID_SOCIEDAD = A.ID_SOCIEDAD
AND B.ID_EMPREGAD = A.ID_EMPREGAD'
IF @F_ALTA IS NOT NULL
SET @STRINGN = @STRINGN + ' AND B.DAT_INI_ACT_EMP =
A.DAT_INI_ACT_EMP'
SET @STRINGN = @STRINGN + ')'
EXEC sp_executesql @STRINGN,
N'@FINI2 datetime out, @FFIN2 datetime out, @CAMP2
varchar(50) out',
@FINI out, @FFIN out , @CAMP out
[/code]

There is documentation on how can I do this in pgsql?

Best Regards,