Обсуждение: CREATE TABLE AS inside of a function
So now that I've got my loops working, on to my next newbie question. I've created my function and in it, I want to loopthrough the results of a select and for each value of my loop counter, I want to create a new table, but I can't figureout how to use a variable in the name of the new table, see below. CREATE OR REPLACE FUNCTION rgio() RETURNS INTEGER as $$ DECLARE lv RECORD; BEGIN FOR lv IN SELECT DISTINCT rg FROM ldevrg LOOP CREATE TABLE rgio_$lv AS SELECTldev FROM ldevrg WHERE rg='$lv'; END LOOP; RETURN 1; END; $$ LANGUAGE plpgsql; Thanks, Kevin
On 7/21/06, Kevin Nikiforuk <Kevin.Nikiforuk@acrodex.com> wrote: > So now that I've got my loops working, on to my next newbie question. I've created my function and in it, I want to loopthrough the results of a select and for each value of my loop counter, I want to create a new table, but I can't figureout how to use a variable in the name of the new table, see below. > > CREATE OR REPLACE FUNCTION rgio() RETURNS INTEGER as $$ > DECLARE > lv RECORD; > > BEGIN > FOR lv IN SELECT DISTINCT rg FROM ldevrg LOOP > CREATE TABLE rgio_$lv AS > SELECT ldev > FROM ldevrg > WHERE rg='$lv'; > END LOOP; > RETURN 1; > END; > $$ LANGUAGE plpgsql; > > Thanks, > Kevin See: http://www.postgresql.org/docs/8.1/static/plpgsql-statements.html#PLPGSQL-STATEMENTS-EXECUTING-DYN Regards, Rodrigo
Rodrigo De Leon wrote: > On 7/21/06, Kevin Nikiforuk <Kevin.Nikiforuk@acrodex.com> wrote: >> So now that I've got my loops working, on to my next newbie >> question. I've created my function and in it, I want to loop through >> the results of a select and for each value of my loop counter, I want >> to create a new table, but I can't figure out how to use a variable >> in the name of the new table, see below. >> >> CREATE OR REPLACE FUNCTION rgio() RETURNS INTEGER as $$ >> DECLARE >> lv RECORD; >> >> BEGIN >> FOR lv IN SELECT DISTINCT rg FROM ldevrg LOOP >> CREATE TABLE rgio_$lv AS >> SELECT ldev >> FROM ldevrg >> WHERE rg='$lv'; >> END LOOP; >> RETURN 1; >> END; >> $$ LANGUAGE plpgsql; >> >> Thanks, >> Kevin > > See: > http://www.postgresql.org/docs/8.1/static/plpgsql-statements.html#PLPGSQL-STATEMENTS-EXECUTING-DYN > Also, I really recommend enough that you read chapters 32. Extending SQL, 33. Triggers, and 36. Pl/pgSQL in their entirety. In fact, to keep up with the linking to them for you: http://www.postgresql.org/docs/8.1/interactive/extend.html http://www.postgresql.org/docs/8.1/interactive/triggers.html http://www.postgresql.org/docs/8.1/interactive/plpgsql.html And, so that I don't feel like I'm becoming one of those rtfm jerks I always complain about: what you need to do is place your CREATE TABLE statement in an EXECUTE directive like so (inside the the FOR body): EXECUTE 'CREATE TABLE rgio_' || $lv || ' AS SELECT ldev FROM ldevrg WHERE rg=\'' || $lv || '\';' -- this line couldhave also been: WHERE rg=' || quote_literal($lv) || ';' EXECUTE takes a query in a string to execute and you need to use string concatenation to build the string if you're using variables from the function in the query. Pl/pgSQL doesn't have any variable substitution inside of strings (like in double quoted string in PHP) which is why you need to use the concatenation bit. -- erik jones <erik@myemma.com> software development emma(r)
So, I've changed my code as Erik suggested: CREATE OR REPLACE FUNCTION rgio() RETURNS INTEGER as $$ DECLARE lv RECORD; BEGIN FOR lv IN SELECT DISTINCT rg FROM ldevrg LOOP EXECUTE 'CREATE TABLErgio_' || $lv || ' AS SELECT ldev FROM ldevrg WHERErg=' || quote_literal($lv) || ';' END LOOP; RETURN 1; END; $$ LANGUAGE plpgsql; And I get: psql:rgio.sql:32: ERROR: syntax error at or near "$" at character 33 QUERY: SELECT 'CREATE TABLE rgio_' || $ $1 || ' AS SELECT ldev FROM ldevrg WHERE rg=' || quote_literal($ $2 ) || ';' END LOOP CONTEXT: SQL statement in PL/PgSQL function "rgio" near line 23 psql:rgio.sql:32: LINE 1: SELECT 'CREATE TABLE rgio_' || $ $1 || ' AS psql:rgio.sql:32: ^ ________________________________ From: pgsql-sql-owner@postgresql.org on behalf of Erik Jones Sent: Fri 7/21/2006 3:04 PM To: Rodrigo De Leon Cc: pgsql-sql@postgresql.org Subject: Re: [SQL] CREATE TABLE AS inside of a function Rodrigo De Leon wrote: > On 7/21/06, Kevin Nikiforuk <Kevin.Nikiforuk@acrodex.com> wrote: >> So now that I've got my loops working, on to my next newbie >> question. I've created my function and in it, I want to loop through >> the results of a select and for each value of my loop counter, I want >> to create a new table, but I can't figure out how to use a variable >> in the name of the new table, see below. >> >> CREATE OR REPLACE FUNCTION rgio() RETURNS INTEGER as $$ >> DECLARE >> lv RECORD; >> >> BEGIN >> FOR lv IN SELECT DISTINCT rg FROM ldevrg LOOP >> CREATE TABLE rgio_$lv AS >> SELECT ldev >> FROM ldevrg >> WHERE rg='$lv'; >> END LOOP; >> RETURN 1; >> END; >> $$ LANGUAGE plpgsql; >> >> Thanks, >> Kevin > > See: > http://www.postgresql.org/docs/8.1/static/plpgsql-statements.html#PLPGSQL-STATEMENTS-EXECUTING-DYN > Also, I really recommend enough that you read chapters 32. Extending SQL, 33. Triggers, and 36. Pl/pgSQL in their entirety. In fact, to keep up with the linking to them for you: http://www.postgresql.org/docs/8.1/interactive/extend.html http://www.postgresql.org/docs/8.1/interactive/triggers.html http://www.postgresql.org/docs/8.1/interactive/plpgsql.html And, so that I don't feel like I'm becoming one of those rtfm jerks I always complain about: what you need to do is place your CREATE TABLE statement in an EXECUTE directive like so (inside the the FOR body): EXECUTE 'CREATE TABLE rgio_' || $lv || ' AS SELECT ldev FROM ldevrg WHERE rg=\'' || $lv || '\';' -- this line couldhave also been: WHERE rg=' || quote_literal($lv) || ';' EXECUTE takes a query in a string to execute and you need to use string concatenation to build the string if you're using variables from the function in the query. Pl/pgSQL doesn't have any variable substitution inside of strings (like in double quoted string in PHP) which is why you need to use the concatenation bit. -- erik jones <erik@myemma.com> software development emma(r) ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to majordomo@postgresql.orgso that your message can get through to the mailing list cleanly
On Mon, 24 Jul 2006, Kevin Nikiforuk wrote: > So, I've changed my code as Erik suggested: > > CREATE OR REPLACE FUNCTION rgio() RETURNS INTEGER as $$ > DECLARE > lv RECORD; > > BEGIN > FOR lv IN SELECT DISTINCT rg > FROM ldevrg > LOOP > > EXECUTE 'CREATE TABLE rgio_' || $lv || ' AS > SELECT ldev > FROM ldevrg > WHERE rg=' || quote_literal($lv) || ';' I think you want something like lv.rg (no special punctuation) rather than $lv in the above.