github.com/pf-qiu/concourse/v6@v6.7.3-0.20201207032516-1f455d73275f/atc/db/migration/migrations/1602860419_drop_builds_resource_id_unique.down.sql (about)

     1  BEGIN;
     2    DROP INDEX builds_resource_id_idx;
     3  
     4    -- prevent conflicts when re-introducing unique constraint by nulling-out all
     5    -- but the current check build for each resource
     6    UPDATE builds b
     7    SET resource_id = NULL
     8    WHERE resource_id IS NOT NULL
     9    AND NOT EXISTS (
    10      SELECT 1
    11      FROM resources
    12      WHERE build_id = b.id
    13    );
    14  
    15    CREATE UNIQUE INDEX builds_resource_id_key ON builds (resource_id);
    16  
    17    ALTER TABLE resources DROP COLUMN build_id;
    18  COMMIT;