There are several ways that you can make this code faster (each one should be faster than the preceding ones, but it gets progressively less idiomatic-slick): Run insertOrUpdateAll instead of insertOrUpdate if on slick-pg 0.16.1+ await(run(TableQuery[FooTable].insertOrUpdateAll rows)).sum Run your DBIO events all at once, rather than waiting for each one to commit before you run … Read more
Exactly as you normally would! val query = for { coffee <- Coffees if coffee.name like “%expresso%” } yield (coffee.name, coffee.price) Will generate SQL like SELECT name, price FROM coffees WHERE NAME like ‘%expresso%’;
The best answer I’ve seen is: https://stackoverflow.com/a/27783730/154248 What’s it used for: imagine you needed to join a table on itself. That tag is a way to distinguish between the tables taking part in a query.
Here’s the relevant documentation page, according to which, you should construct a query like this: val insertQuery = items returning items.map(_.id) into ((item, id) => item.copy(id = id)) def create(name: String, price: Double) : Future[Item] = { val action = insertQuery += Item(0, name, price) db.run(action) }
You can also write (Person.apply _).tupled to avoid repeating the types.
Slick 2.X: You can print the query statement as shown on the Slick documentation: val invoker = q.invoker val statement = q.selectStatement For other type of statements look at insertStatement, deleteStatement and updateStatement. Slick 3.X: val res = table.filter(_.id === 1L).result res.statements.foreach(println) Docs.
With recent versions of Slick, this way of writing it works: Users.filter(_.id === filterId) .map(x => (x.name, x.age)) .update((“john”, 99)) Be careful to remember the extra parentheses if you are updating more than one property otherwise you might get a compiler warning.
You find an example on how to use the cake pattern / dependency injection to decouple the Slick driver from the database access layer here: https://github.com/slick/slick-examples. How to decouple the Slick driver and test application with FakeApplication A few days ago I wrote a Slick integration library for play, which moves the driver dependency to … Read more
[UPDATE] – added (yet another) explanation on for comprehensions The * method: This returns the default projection – which is how you describe: ‘all the columns (or computed values) I am usually interested’ in. Your table could have several fields; you only need a subset for your default projection. The default projection must match the … Read more