pub async fn migrate(conn: &Connection, dir: &str) -> Result<()>Expand description
Run SQL migrations from a directory against a connection.
Reads *.sql files sorted by filename, tracks applied migrations
in a _migrations table with checksum verification. Each migration
is applied inside a transaction so the schema change and the
_migrations record are committed atomically.
Already-applied migrations are skipped. If a file’s checksum differs from the recorded checksum, an error is returned (the file was modified after being applied).
§Errors
Returns an error if the migrations directory cannot be read, a migration file cannot be parsed, a checksum mismatch is detected, or a migration statement fails.