Re: how postgresql passes the parameter to the function. syntax error near or at "$1".

Pavel,

Thanks a lot.

Regards.

Grace

At 2012-03-29 00:27:12,"Pavel Stehule [via PostgreSQL]" <ml-node+s1045698n5601077h29(at)n5(dot)nabble(dot)com> wrote:
Hello

parameter - $n cannot be used on table name or column name position.
Some statements - DROP, VACUUM, ANALYZE doesn't support parameters
ever.

You have to use dynamic SQL in these cases.

CREATE OR REPLACE FUNCTION foo(tablename text, value text)
RETURNS void AS $$
BEGIN
EXECUTE 'insert into ' || quote_ident(tablename) || ' VALUES($1)' USING value;
END;
$$ LANGUAGE plpgsql

Regards

Pavel Stehule

2012/3/28 leaf_yxj <[hidden email]>:

> I want to create a function which use to truncate the table specified by the
> caller. I very confused how postgresql pass this parameter into the function
> :
>
> as a superuser to execute :
> 1)
> create or replace function d() returns void as $$
> analyze;
> $$ language sql;
>
>
> ----- this works when i issue select d()
>
> 2) this doesn't work
>
> create or replace function v(text) returns void as $$
> analyze $1;
> $$ language sql;
>
> why???? and how to correct it?
>
>
> I tried another function for insert
>
> 1) this works.
>
> create or replace function insert_f(integer) returns void as $$
> insert into t1 values($1);
> $$ language sql;
>
> ----this works when i issue select insert_f(20);
>
> 2) this doesn't work.
>
> create or replace function insert_f(text,integer) returns void as $$
> insert into $1 values($2);
> $$ language sql;
>
> ---- it failed to create the function and give me error : syntax error at or
> near "$1".
>
> Please help.
>
> Thanks.
>
> Regards.
>
> Grace
>
>
>
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