How to catch slick postgres exceptions for duplicate key value violations

Question

My table has a unique index on a pair of columns in my postgresql database.

I want to know how I can catch a duplicate key exception when I am inserting:

<         


        

Answer 1

In Slick 3.x you can use asTry.

I'm using MySQL, but the same code can be used for PostgreSQL, only the exceptions are different.

import scala.util.Try
import scala.util.Success
import scala.util.Failure

db.run(myAction.asTry).map {result =>  

  result match {

    case Success(res) => 
      println("success")
      // ...

    case Failure(e: MySQLIntegrityConstraintViolationException) => {
      //code: 1062, status: 23000, e: Duplicate entry 'foo' for key 'name'
      println(s"MySQLIntegrityConstraintViolationException, code: ${e.getErrorCode}, sql status: ${e.getSQLState}, message: ${e.getMessage}")
      // ...
    }

    case Failure(e) => {
      println(s"Exception in insertOrUpdateListItem, ${e.getMessage}")
      // ...
    }
  }
}

Note: It's also possible to map the action (myAction.asTry.map ...) instead of the future returned by db.run.