zab08 <zab08@xxxxxxx> wrote: > > I have two table: > > > CREATE TABLE roles(role_name varchar(255) primary key); > > CREATE TABLE roles_permissions(permission varchar(100), role_name varchar > (100)); > > here is result by : > SELECT * from roles; > role_name > ----------- > role1 > role2 > (2 rows) > > here is result by : > SELECT * from roles_permissions ; > role_name | permission > -----------+------------- > role1 | permission1 > role1 | permission2 > role2 | permission1 > (3 rows) > > ---------------------------------------- ----------------------------------- > > after the command: > SELECT * from roles, roles_permissions; That's a CROSS-JOIN > role_name | role_name | permission > -----------+-----------+------------- > role1 | role1 | permission1 > role1 | role1 | permission2 > role1 | role2 | permission1 > role2 | role1 | permission1 > role2 | role1 | permission2 > role2 | role2 | permission1 > > > the expected result is: > role_name | permission > -----------+------------- > role1 | permission1,permission2, > & nbsp;role2 | permission1 > > > for short: > afer join of two table, here is some repeat columns, yeah, it's a cross-join. Rewrite your query, adding a WHERE-condition: where roles.role_name = roles_permissions.role_name Regards, Andreas -- Really, I'm not out to destroy Microsoft. That will just be a completely unintentional side effect. (Linus Torvalds) "If I was god, I would recompile penguin with --enable-fly." (unknown) Kaufbach, Saxony, Germany, Europe. N 51.05082°, E 13.56889° -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
