postgresql - Want to get schema name,table name and column name when wildcard search for a record in entire database

Question

I have been trying the below code for a wildcard search of a record in the entire database.But returns only the result set with exact match.

CREATE OR REPLACE FUNCTION search_columns(
    needle text,
    haystack_tables name[] default '{}',
    haystack_schema name[] default '{}'
)
RETURNS table(schemaname text, tablename text, columnname text, rowctid text)
AS $$
begin
  FOR schemaname,tablename,columnname IN
      SELECT c.table_schema,c.table_name,c.column_name
      FROM information_schema.columns c
        JOIN information_schema.tables t ON
          (t.table_name=c.table_name AND t.table_schema=c.table_schema)
        JOIN information_schema.table_privileges p ON
          (t.table_name=p.table_name AND t.table_schema=p.table_schema
              AND p.privilege_type='SELECT')
        JOIN information_schema.schemata s ON
          (s.schema_name=t.table_schema)
      WHERE (c.table_name=ANY(haystack_tables) OR haystack_tables='{}')
        AND (c.table_schema=ANY(haystack_schema) OR haystack_schema='{}')
        AND t.table_type='BASE TABLE'
  LOOP
    FOR rowctid IN
      EXECUTE format('SELECT ctid FROM %I.%I WHERE cast(%I as text)=%L',
       schemaname,
       tablename,
       columnname,
       needle
      )
    LOOP
      -- uncomment next line to get some progress report
      -- RAISE NOTICE 'hit in %.%', schemaname, tablename;
      RETURN NEXT;
    END LOOP;
 END LOOP;
END;
$$ language plpgsql

This returns only for exact match of record.I need all wildcard matches with its schema name,table name and column name

select * from search_columns('foo');

Answer 1

You need to construct a LIKE expression, not compare for equality:

  EXECUTE format('SELECT ctid FROM %I.%I WHERE cast(%I as text) LIKE %L',
   schemaname,
   tablename,
   columnname,
   concat('%', needle, '%')
  )

If you want a case insensitive comparison use ILIKE instead.