Temp table is not a known variable

Question

I've got a temp table which I want to use twice to insert into it:

CREATE OR REPLACE FUNCTION test1(user_id BIGINT) RETURNS BIGINT AS
$BODY$
BEGIN
  DROP TABLE IF EXISTS temp_table1;
  create temp table temp_table1
  on commit drop
  as select * from get_some_data($1); -- try to get the data for the 1st time

  if not exists (select * temp_table1) then
    select try_to_update_data($1); -- updates data, returns void
  end if;

  -- try to get the data again
  select * into temp_table1 from get_some_data($1); -- error!
  if not exists (select * from temp_table1) then
    return 0;
  end if;

  --........ use temp_table1

It trows the error:

ERROR:  "temp_table1" is not a known variable

How do I solve this?

Answer 1

write INSERT INTO temp_table1 SELECT get_some_data($1);

in place of what you had

select * into temp_table1 from get_some_data($1); -- error!

May be this will work for you.

Answer 2

RowanStone is looking for a more detailed answer to this question.

The reason the SELECT INTO does not work is because there are two contexts to execute it and SELECT INTO TABLE in not available in PL/pgSQL:

SELECT INTO:

SELECT [ ALL | DISTINCT [ ON ( expression [, ...] ) ] ]
     * | expression [ [ AS ] output_name ] [, ...]
INTO [ TEMPORARY | TEMP | UNLOGGED ] [ TABLE ] new_table

CREATE TABLE AS is functionally similar to SELECT INTO. CREATE TABLE AS is the recommended syntax, since this form of SELECT INTO is not available in ECPG or PL/pgSQL, because they interpret the INTO clause differently.

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43.5.3. Executing a Command with a Single-Row Result

The result of an SQL command yielding a single row (possibly of multiple columns) can be assigned to a record variable, row-type variable, or list of scalar variables. This is done by writing the base SQL command and adding an INTO clause.

SELECT select_expressions INTO [STRICT] target FROM ...;

where target can be a record variable, a row variable, or a comma-separated list of simple variables and record/row fields.

Note that this interpretation of SELECT with INTO is quite different from PostgreSQL's regular SELECT INTO command, wherein the INTO target is a newly created table. If you want to create a table from a SELECT result inside a PL/pgSQL function, use the syntax CREATE TABLE ... AS SELECT.

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Either INSERT INTO SELECT should be used(append) or DROP TABLE and CREATE TABLE AS SELECT ... instead.