db-migration

name	db-migration
description	Add a new append-only database migration for WP Project Manager. Updates db/migrations/, db/Create_Table.php, the Eloquent model fillable/casts, and the Fractal transformer. TRIGGER when the user says 'add a column', 'new table', 'schema change', 'migration', 'alter wp_pm_*', invokes /db-migration, or describes a feature that requires a DB change.

DB Migration

When to use this skill

Any schema change to a wp_pm_* table OR a new wp_pm_* table. NEVER edit a shipped migration or rewrite history.

Procedure

1. Audit existing migrations.

   ls db/migrations/
   

   Note the naming convention used (timestamp, version-prefix, or sequential). Match it.

2. Confirm the change is forward-only.

   • Adding a column: OK.
   • Adding a table: OK.
   • Adding an index: OK.
   • Renaming a column: forbidden in one step. Multi-step: add new + dual-write + backfill + drop old (separate releases).
   • Dropping a column: requires explicit user approval.

3. Write the migration file. Template:

   <?php
   global $wpdb;
   
   $table   = $wpdb->prefix . 'pm_tasks';
   $charset = $wpdb->get_charset_collate();
   
   // Idempotent: check before ALTER
   $col_exists = $wpdb->( ->(
       , 
   ) );
   
    ( !  ) {
       ->(  );
   }