Re: Help with function - Mailing list pgsql-sql
From | CHRIS HOOVER |
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Subject | Re: Help with function |
Date | |
Msg-id | NZb07058-646270b1@companiongroup.com Whole thread Raw |
In response to | Help with function ("CHRIS HOOVER" <CHRIS.HOOVER@companiongroup.com>) |
Responses |
Re: Help with function
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List | pgsql-sql |
Thanks a bunch for the pointers and help. One other hopefully quick question. How do you query using a variable containing the query? I'm trying to build a select statment based upon what parameters are being passed to the function. somthing like this: Declare Param1 varchar; Param2 varchar; SQLStr varchar; Table_rec Table%ROWTYPE; Begin SQLStr:="select * from table"Param1:= $1; Param2 :=$2; if (Param1 is not null) then SQLStr := SQLStr || "where column=Param1"; else SQLStr := SQLStr || "where column=Param2"; end if; SQLStr := SQLStr || ";" for Table_Rec in SQLStr loop return next Table_rec; end loop; return; end; Is this possible? Thanks again for any help, Chris ------------------( Forwarded letter 1 follows )--------------------- Date: Mon, 20 Sep 2004 13:51:09 -0700 (PDT) To: chris.hoover Cc: pgsql-sql@postgresql.org.comp From: Stephan.Szabo[sszabo]@megazone.bigpanda.com.comp Subject: Re: [SQL] Help with function On Mon, 20 Sep 2004, CHRIS HOOVER wrote: > I need some help writing a simple function. > > Due to some program limitations for a program I run the db's for, I'm having > to write some simple functions to run some selects. However, I am not sure > how to have them correctly return the record(s) selected and/or how to > properly call them from sql. > > Would someone be so kind as to help me with this. > > Here is an example function: > > CREATE OR REPLACE FUNCTION "public"."test_func" (varchar) RETURNS SETOF > "public"."test_tbl" AS' > Declare > PCN varchar; > test_tbl_rec clmhdr%ROWTYPE; > > Begin > > PCN := $1; > > select into test_tbl_rec * from test_tbl where test_tbl.pcn = PCN; > return test_tbl_rec; > > end; > 'LANGUAGE 'plpgsql' VOLATILE RETURNS NULL ON NULL INPUT SECURITY INVOKER; If you want to return sets of rows, you're going to need to loop over the returned rows from the select using return next. These links may help: http://www.varlena.com/varlena/GeneralBits/26.html http://techdocs.postgresql.org/guides/SetReturningFunctions > I was trying to call this function from psql using: > select test_func('asdf'); As a side note, plpgsql set returning functions cannot be called in a select list, only in the from clause (the above links will have examples).