postgresql-9.1

I am using PostgreSQL 9.1 and need help with concatenating multiple rows in one. I need to do that in 2 tables. When I use two times array_agg() functions I get duplicated values in result. Tables: CREATE TABLE rnp (id int, grp_id int, cabinets varchar(15) ); INSERT INTO rnp VALUES (1,'11','cabs1') ,(2,'11','cabs2') ,(3,'11','cabs3') ,(4,'11','cabs4') ,(5,'22','c1') ,(6,'22','c2'); CREATE TABLE ips (id int, grp_id int, address varchar(15)); INSERT INTO ips VALUES (1,'11','NY') ,(2,'11','CA') ,(3,'22','DC') ,(4,'22','LA'); SQL: SELECT DISTINCT rnp.grp_id, array_to_string(array_agg(rnp.cabinets

Does anyone know how to find the OID of a table in Postgres 9.1? I am writing an update script that needs to test for the existence of a column in a table before it tries to create the column. This is to prevent run of the script after the first from erroring out. The postgres catalog table pg_class is what you should look at. There should be one row per table, with the table name in the column relname , and the oid in the hidden column oid . The catalog tables are in the postgres database, so make sure to connect to that, rather than your application database. You may also be interested in

I have a PostgreSQL 9.1 database with 100 or so tables that were loaded into the 'public' schema. I would like to move those tables (but not all of the functions in 'public') to a 'data' schema. I know that I can use the following to move 1 table at a time. ALTER TABLE [tablename] SET SCHEMA [new_schema] Is it possible to move all of the tables to the new schema in one operation? If so, what would be the most efficient way to accomplish this task? DO will do the trick: DO $$ DECLARE row record; BEGIN FOR row IN SELECT tablename FROM pg_tables WHERE schemaname = 'public' -- and other conditions

Does anyone know if it's even possible (and how, if yes) to query a database server setting in PostgreSQL (9.1)? I need to check the max_connections (maximum number of open db connections) setting. Can be as simple as: SHOW max_connections; This returns the currently effective setting. Be aware that it can differ from the setting in postgresql.conf as there are a couple of ways to set run-time parameters in PostgreSQL . To reset the "original" setting from postgresql.conf in your current session: RESET max_connections; However, not applicable to this particular setting. Per documentation :

Is there a way how I can convert the following string back to the human-readable value? I have some external data where all non-ascii characters are escaped. Example strings: 16 StringProvider_111=Telefon\u00ED kontakty 17 StringProvider_116=Odpov\u011Bdn\u00E1 osoba Required Result: 16 StringProvider_111=Telefoní kontakty 17 StringProvider_116=Odpovědná osoba SQLFiddle The database has UTF8 encoding and collation cs_CZ.UTF-8 One old trick is using parser for this purpose: postgres=# select e'Telefon\u00ED kontakty'; ?column? ------------------- Telefoní kontakty (1 row) CREATE OR REPLACE

In one of my select statements I've got the following error: ERROR: failed to find conversion function from unknown to text ********** Error ********** ERROR: failed to find conversion function from unknown to text SQL state: XX000 This was easy to fix using cast , but I do not fully understand why it happened. I will ilustrate my confusion with two simple statements. This one is OK: select 'text' union all select 'text'; This will return error: with t as (select 'text') select * from t union all select 'text' I know I can fix it easily: with t as (select 'text'::text) select * from t union