Slick 3.0 bulk insert or update (upsert)

Question

what is the correct way to do a bulk insertOrUpdate in Slick 3.0?

I am using MySQL where the appropriate query would be

INSERT INTO table (a,b,c) VAL         


        

Answer 1

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 the next:

  val toBeInserted = rows.map { row => TableQuery[FooTable].insertOrUpdate(row) }
  val inOneGo = DBIO.sequence(toBeInserted)
  val dbioFuture = run(inOneGo)
  // Optionally, you can add a `.transactionally`
  // and / or `.withPinnedSession` here to pin all of these upserts
  // to the same transaction / connection
  // which *may* get you a little more speed:
  // val dbioFuture = run(inOneGo.transactionally)
  val rowsInserted = await(dbioFuture).sum
  

• Drop down to the JDBC level and run your upsert all in one go (idea via this answer):

  val SQL = """INSERT INTO table (a,b,c) VALUES (?, ?, ?)
  ON DUPLICATE KEY UPDATE c=VALUES(a)+VALUES(b);"""
  
  SimpleDBIO[List[Int]] { session =>
    val statement = session.connection.prepareStatement(SQL)
    rows.map { row =>
      statement.setInt(1, row.a)
      statement.setInt(2, row.b)
      statement.setInt(3, row.c)
      statement.addBatch()
    }
    statement.executeBatch()
  }