Scala slick update table after querying with a join - scala

Question

I want to update a table but the row needs to be selected based on certain conditions. Following code compiles fine but throws run-time exception:
play.api.http.HttpErrorHandlerExceptions$$anon$1: Execution exception[[SlickException: A query for an UPDATE statement must resolve to a comprehension with a single table -- Unsupported shape: Comprehension s2, Some(Apply Function =), None, ConstArray(), None, None, None, None]]
Here is the function (the intention is to allow update only for qualified user):
def updateRecord(record: Record)(implicit loggedInUserId: User) = {
val q = records.withFilter(_.id === record.id).join(companies).on(_.companyId === _.id).filter(_._2.userid === loggedInUserId)
val recordToUpdate = q.map { case (r, c) => r }
val action = for {
c <- recordToUpdate.update(record)
} yield (c)
... // there are other actions in the for comprehension, removed them for clarity
I thought the result of the map is a row from the records table (not a tuple) but the errors seems to be indicating that I am not updating a "single" table.
Or is there a better way of doing query + update?

Answer 1

Yes, you seem to try updating both tables.
Maybe you should try something like
def updateRecord(record: Record)(implicit loggedInUserId: User): Future[Int] = {
val recordToUpdate = records.filter(_.id === record.id)
val q = recordToUpdate
.join(companies).on(_.companyId === _.id)
.filter(_._2.userid === loggedInUserId)
.exists
val action = for {
c <- recordToUpdate.update(record)
// ...
} yield c
for {
isLoggedIn <- db.run(q.result)
if isLoggedIn
c <- db.run(action)
} yield c
}
You can also try
def updateRecord(record: Record)(implicit loggedInUserId: User):
DBIOAction[Int, NoStream, Read with Write with Transactional] = {
val recordToUpdate = records.filter(_.id === record.id)
val action =
recordToUpdate
.join(companies).on(_.companyId === _.id)
.filter(_._2.userid === loggedInUserId)
.exists
.result
(for {
isLoggedIn <- action
if isLoggedIn
c <- recordToUpdate.update(record)
// ...
} yield c).transactionally
}
Variant that should work without NoSuchElementException: Action.withFilter failed. Based on the answer.
def updateRecord(record: Record)(implicit loggedInUserId: User):
DBIOAction[Int, NoStream, Read with Write with Transactional] = {
val recordToUpdate = records.filter(_.id === record.id)
val action =
recordToUpdate
.join(companies).on(_.companyId === _.id)
.filter(_._2.userid === loggedInUserId)
.exists
.result
action.flatMap {
case true => for {
c <- recordToUpdate.update(record)
// ...
} yield c
case false => DBIO.successful(0) /*DBIO.failed(new IllegalStateException)*/
}.transactionally
}