marv | programmatic database migration tool with plugable drivers | SQL Database library

marv is a JavaScript library typically used in Database, SQL Database applications. marv has no bugs, it has no vulnerabilities, it has a Permissive License and it has low support. You can install using 'npm i marv' or download it from GitHub, npm.

Marv is unlike some other migration libraries in that it deliberately doesn't run your scripts in a transaction. This is because some SQL statements cannot be run in a transaction, and others(e.g. locking in Postgres) will automatically commit the current transaction if one exists. Unfortunately this means that in rare situations, scripts may be only partially applied, e.g. If something goes wrong (e.g. a network outage) after CREATE TABLE but before CREATE INDEX, the table would be created without the index. Because scripts are audited on successful completion, the script will be included in the next migration run, but now the CREATE TABLE step will fail because the table already exists. One way to work around this is by explicitly specifying a transactions... However there's still a gotcha. Now the script will either be applied or not, but consider what will happen if the network outage occurs after the script has been applied, but before Marv inserts the audit record? Because the script hasn't been audited, Marv won't know that it completed successfully and will still include it in the next migration run. Once again it will fail on the CREATE TABLE step. A better workaround is to make your script idempotent, e.g. Unfortunately not all statements and SQL dialects have an equivalent of IF NOT EXISTS. If you're especially unlucky and something goes wrong while applying a non-atomic / non-idempotent script you will have some manual clean up to do. This may involve applying the missing steps and inserting the audit record manually. The exact syntax will vary from driver to driver but should be similar to...