Rename pascal column names to snake case columns names in postgresql

rename_pascal_columns.sql

SELECT ddlsql || regexp_replace(name, E'^_',E'','g') || ';' as ddlsql FROM
(
SELECT  'ALTER TABLE ' || quote_ident(c.table_schema) || '.'
  || quote_ident(c.table_name) || ' RENAME "' || c.column_name || '" TO ' As ddlsql, quote_ident(lower(regexp_replace(column_name, E'([A-Z])', E'\_\\1','g'))) as name
  FROM information_schema.columns As c
  WHERE c.table_schema NOT IN('information_schema', 'pg_catalog') 
      AND c.column_name <> lower(c.column_name) 
  ORDER BY c.table_schema, c.table_name, c.column_name
) x;