PostgreSQL CREATE TEMPORARY TABLE inside a plpgsql function

Question

I am trying to create a function that does this:

drop table t_rv_openitem;
select * into t_rv_openitem from rv_openitem;
select * from t_rv_openitem;

I am confused sometimes when it comes to functions in PostgreSQL and get this error:

An error has occurred:

ERROR: syntax error at or near "DROP" LINE 3: DROP TABLE t_rv_openitem;

I know this seems like a simple task but I am pulling my hair out trying to figure this out.

Here is the full function create statement:

CREATE OR REPLACE FUNCTION adempiere.update_t_rv_openitem()
  RETURNS rv_openitem AS
$BODY$

Drop table t_rv_openitem;
select * into t_rv_openitem from rv_openitem;
select * From t_rv_openitem;

$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;
ALTER FUNCTION adempiere.update_t_rv_openitem() OWNER TO adempiere; 

Answer 1

Just add BEGIN and END

CREATE OR REPLACE FUNCTION adempiere.update_t_rv_openitem()
  RETURNS rv_openitem AS
$BODY$

BEGIN -- ADD THIS

Drop table t_rv_openitem;
select * into t_rv_openitem from rv_openitem;
select * From t_rv_openitem;

END; -- AND THIS

$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;
ALTER FUNCTION adempiere.update_t_rv_openitem() OWNER TO adempiere; 

You don't need BEGIN and END block if you are using LANGUAGE sql, you need those though if you are using LANGUAGE plpgsql

UPDATE

Regarding ERROR: syntax error at "t_rv_openitem" DETAIL: Expected record variable.... There's no syntax error on your code, you just need to change this:

select * into t_rv_openitem from rv_openitem;

To this:

create table t_rv_openitem as
select * from rv_openitem;

The table creation using SELECT * INTO tablehere FROM tableSource works only if you are using it outside of PLPGSQL; when that code struct is inside PLPGSQL, the semantic will be different, it means:

SELECT * INTO declaredVariableHere FROM tableSource;

To make table creation work on both stand-alone statement and inside PLPGSQL, just use:

CREATE TABLE AS SELECT * FROM tableSourceHere;