Re: PL/PGSQL - How to pass in variables?

On 5/14/06, Scott Yohonn <syohonn(at)gmail(dot)com> wrote:
>
> Using PL/PGSQL, I am trying to create a procedure to display the
> count of rows in any single table of a database. The End-user would
> pass in a table name and the prodecure would display the table name
> with the row count.
> I am able to hardcode the variable for table and get the appropriate
> results from my count function (see below), but cannot pass in a
> variable and have the function work. Any suggesstions???
>
> CREATE FUNCTION get_table_count(tablename text) RETURNS integer AS $$
> DECLARE
>
> --tablename ALIAS FOR $1;
>
> rowcount INTEGER;
> BEGIN
>
> SELECT INTO rowcount count(*) FROM tablename;
>
> RETURN rowcount;
>
> END;
> $$ LANGUAGE 'plpgsql';
>

you can't do this because tablename is a variable not a table, you
have to append the content of the variable in a string that can be
EXECUTE'd

EXECUTE 'SELECT count(*) FROM ' || tablename INTO rowcount;

--
regards,
Jaime Casanova

"Programming today is a race between software engineers striving to
build bigger and better idiot-proof programs and the universe trying
to produce bigger and better idiots.
So far, the universe is winning."
Richard Cook