jet/wiki/LOCK.md

LOCK statement obtains a table-level lock, waiting if necessary for any conflicting locks to be released. More about LOCK statement in PostgreSQL: https://www.postgresql.org/docs/11/sql-lock.html

Following clauses are supported:

• IN(mode) - mode specifies which locks this lock conflicts with.
  Mode can be:
  • jet.LOCK_ACCESS_SHARE
  • jet.LOCK_ROW_SHARE
  • jet.LOCK_ROW_EXCLUSIVE
  • jet.LOCK_SHARE_UPDATE_EXCLUSIVE
  • jet.LOCK_SHARE
  • jet.LOCK_SHARE_ROW_EXCLUSIVE
  • jet.LOCK_EXCLUSIVE
  • jet.LOCK_ACCESS_EXCLUSIVE
• NOWAIT() - locked table should not wait for any conflicting locks to be released. If the specified lock(s) cannot be acquired immediately without waiting, the transaction is aborted.

Example

lockStmt := Address.
        LOCK().
        IN(jet.LOCK_ACCESS_SHARE).
        NOWAIT()

Debug SQL of above statement:

LOCK TABLE dvds.address IN ACCESS SHARE MODE NOWAIT;

Execute statement

To execute update statement and get sql.Result:

res, err := lockStmt.Exec(db)

Use ExecContext to provide context object to execution.