Rename all columns from all tables with specific column name in PostgreSQL?

Question

Is there a way I can rename all column names that are called 'location' to 'location_name' within all schemas in my PostgreSQL database?

I am fairly new to SQL and am aware there is an ALTER TABLE command but don't know if it is possible to somehow loop through all tables?

Answer 1

You need dynamic SQL for this using an anonymous PL/pgSQL block to do this in an automated way:

do
$$
declare
  l_rec record;
begin
  for l_rec in (select table_schema, table_name, column_name 
                from information_schema.columns 
                where table_schema = 'public' 
                  and column_name = 'location') loop
     execute format ('alter table %I.%I rename column %I to %I_name', l_rec.table_schema, l_rec.table_name, l_rec.column_name, l_rec.column_name);
  end loop;
end;
$$

If you have multiple schemas or your tables are not in the public schema, replace the condition where table_schema = 'public' with the appropriate restriction.

Answer 2

If you have superuser privileges you can make the changes in one sweep in the system catalogs:

UPDATE pg_attribute
SET attname = 'location_name'
WHERE attname = 'location';

Answer 3

I think the closest you will get is running something like this:

SELECT FORMAT(
  'ALTER TABLE %I.%I.%I RENAME COLUMN %I TO %I;',
  catalog_name,
  schema_name,
  table_name,
  column_name,
  'location_name'
)
FROM information_schema.columns
WHERE column_name = 'location';

If you run that in psql, you can follow it with \\gexec and it should work.

Answer 4

You can fetch all location columns in your database with

SELECT * FROM information_schema.columns WHERE column_name = 'location';

And probably use some programming language to then execute all rename queries. There are information_schema tables in almost every database management system (although, they are sometimes called/structured differently).