PostgreSQL: Create table if not exists AS

Question

I\'m using PostgreSQL and am an SQL beginner. I\'m trying to create a table from a query, and if I run:

CREATE TABLE table_name AS
   (....query...)
<         


        

Answer 1

Try this,

create or replace function create_table(tblname text) returns text as
$$ 
BEGIN
$1 = trim($1);
IF not EXISTS (select relname from pg_stat_user_tables where relname =$1) THEN
execute 'create table '||$1||' as select * from tbl'; -- 
return ''||$1||' Created Successfully !!';
else
return  ''||$1||' Already Exists !!';
END IF;
END
$$
language plpgsql 

---

create or replace function create_table_qry(tblname text,qry text) returns text as
$$ 
BEGIN
$1 = trim($1);
IF not EXISTS (select relname from pg_stat_user_tables where relname =$1) THEN
execute 'create table '||$1||' as '||$2||'';
return ''||$1||' Created Successfully !!';
else
return  ''||$1||' Already Exists !!';
END IF;
END
$$
language plpgsql