PosgtreSQL - Change multiple fields collation in one query I have small database with few text fields with "default" collation. I don't want to recreate database. What is the query to alter all problematic fields at once?

To change the single one I can use

ALTER TABLE a_table_name ALTER a_column_name TYPE text COLLATE a_collate;
There isn't a single SQL command that will do that for you.  You can write a loop in a different language, using the results from

SELECT table_name, column_name
  FROM information_schema.columns
  WHERE table_schema IN ('your_schemas')
    AND data_type = 'text'
    AND collation_name IS NULL;


or similar.