The install script

1. In your package's script.php, type jinstaller and pick the snippet.
2. It expands to a thin Pkg_<Name>InstallerScript subclass over a uniquely-named base — so two packages updating together can never hit Cannot redeclare class.

Schema changes

1. In a sql/updates file, type jddl for conditional DDL that avoids PREPARE/EXECUTE (the cause of SQL error 1295).
2. Add jselfheal in the install script for an install+update self-heal hook that applies column/index changes idempotently via information_schema checks.

Part of the Moko VS Code suite.