Thread: Changing column names in tables
I have an Access database that I have exported to PostgreSQL via ODBC, which has worked ok & the data is in PostgreSQL but some of the column names were in mixed case e.g. AccountCode
When I look at the table definitions in pgadmin these are shown in quotes e.g."AccountCode" and any queries made that reference these columns require the quotes.
There are too many fields to issue alter table commands to rename in SQL so my question is , is it safe to use a query such as
select relfilenode from pg_class where relname='rates'
update pg_attribute set attname=lower(attname) where attnum >0 and attrelid=23424
Why are there too many to fix with ALTER?
Use SQL and the data dictionary to generate the DDL and pipe it into psql (or spool it to disk and use that file as a sql script):
psql your_db_name -t -c "select 'alter table '||t.tablename||' rename \"'||c.column_name||'\" to '||lower(c.column_name)||';' from pg_tables t, information_schema.columns c where t.schemaname='your_schema_name' and c.table_name=t.tablename and c.table_schema=t.schemaname and c.column_name<>lower(c.column_name)" | psql your_db_name
From: pgsql-general-owner@postgresql.org [mailto:pgsql-general-owner@postgresql.org] On Behalf Of Tony Cade
Sent: Wednesday, March 05, 2008 2:29 PM
To: pgsql-general@postgresql.org
Subject: [GENERAL] Changing column names in tables
I have an Access database that I have exported to PostgreSQL via ODBC, which has worked ok & the data is in PostgreSQL but some of the column names were in mixed case e.g. AccountCode
When I look at the table definitions in pgadmin these are shown in quotes e.g."AccountCode" and any queries made that reference these columns require the quotes.
There are too many fields to issue alter table commands to rename in SQL so my question is , is it safe to use a query such as
select relfilenode from pg_class where relname='rates'
update pg_attribute set attname=lower(attname) where attnum >0 and attrelid=23424
Why are there too many to fix with ALTER?
I mean that there are too many to fix with manually typed ALTER statements, pure laziness, so I am looking at an automated method.
Use SQL and the data dictionary to generate the DDL and pipe it into psql (or spool it to disk and use that file as a sql script):psql your_db_name -t -c "select 'alter table '||t.tablename||' rename \"'||c.column_name||'\" to '||lower(c.column_name)||';' from pg_tables t, information_schema.columns c where t.schemaname='your_schema_name' and c.table_name=t.tablename and c.table_schema=t.schemaname and c.column_name<>lower(c.column_name)" | psql your_db_name
Thank you for your suggestion I will try it.
Tony Cade
Tony Cade
From: pgsql-general-owner@postgresql.org [mailto:pgsql-general-owner@postgresql.org] On Behalf Of Tony Cade
Sent: Wednesday, March 05, 2008 2:29 PM
To: pgsql-general@postgresql.org
Subject: [GENERAL] Changing column names in tables
I have an Access database that I have exported to PostgreSQL via ODBC, which has worked ok & the data is in PostgreSQL but some of the column names were in mixed case e.g. AccountCode
When I look at the table definitions in pgadmin these are shown in quotes e.g."AccountCode" and any queries made that reference these columns require the quotes.
There are too many fields to issue alter table commands to rename in SQL so my question is , is it safe to use a query such as
select relfilenode from pg_class where relname='rates'
update pg_attribute set attname=lower(attname) where attnum >0 and attrelid=23424