Transactions

[elcritch]

This takes a different, simpler approach than the other PR. Transactions are just simple try excepts that handle setting up transactions instead of trying make query support multi-statements and then including transactions in the DSL.

  test "commit on success":
    transaction:
      query:
        insert person(id = ?(101), name = ?"john101", password = ?"p101", email = ?"john101@mail.com", salt = ?"s101", status = ?"ok")
    check db.getValue(sql"select count(*) from person where id = 101") == "1"

  test "rollback on error with else":
    # prepare one row
    var failed = false
    query:
      insert person(id = ?(501), name = ?"john501", password = ?"p501", email = ?"john501@mail.com", salt = ?"s501", status = ?"ok")
    # in transaction insert a new row and then violate PK
    transaction:
      query:
        insert person(id = ?(502), name = ?"john502", password = ?"p502", email = ?"john502@mail.com", salt = ?"s502", status = ?"ok")
      # duplicate key error
      query:
        insert person(id = ?(501), name = ?"dup", password = ?"p", email = ?"e", salt = ?"s", status = ?"x")
      check false # should not reach
    else:
      echo "do something else..."
      failed = true

Outer try excepts:

  test "rollback on error with manual try except":
    # prepare one row
    query:
      insert person(id = ?(201), name = ?"john201", password = ?"p201", email = ?"john201@mail.com", salt = ?"s201", status = ?"ok")
    # in transaction insert a new row and then violate PK
    try:
      transaction:
        query:
          insert person(id = ?(202), name = ?"john202", password = ?"p202", email = ?"john202@mail.com", salt = ?"s202", status = ?"ok")
        # duplicate key error
        query:
          insert person(id = ?(201), name = ?"dup", password = ?"p", email = ?"e", salt = ?"s", status = ?"x")
      check false # should not reach
    except DbError as e:
      discard

[Araq]

Unused?

[elcritch]

Ah, so that is something GPT5 added. I'd committed the first changes already when I saw these. It looked odd but I figured they already existed.

I'm not sure if these are any better to use than a plain db.exec. Is doing the prepare statement and query steps beneficial? Seems like a bit of AI slop to drop.

[Araq]

Good enough for me. Further improvements can be done as new PRs.