Data commit

Task/Parameterized-SQL-statement/Scala/parameterized-sql-statement.scala

@@ -0,0 +1,57 @@
+import slick.jdbc.H2Profile.api._
+import slick.sql.SqlProfile.ColumnOption.SqlType
+
+import scala.concurrent.Await
+import scala.concurrent.ExecutionContext.Implicits.global
+import scala.concurrent.duration.Duration
+
+object PlayersApp extends App {
+  lazy val playerRecords = TableQuery[PlayerRecords]
+  val db = Database.forURL("jdbc:h2:mem:test1;DB_CLOSE_DELAY=-1", driver = "org.h2.Driver")
+  //  Pre-compiled parameterized statement
+  val compiledUpdate = Compiled { jerseyN: Rep[Int] =>
+    for {c <- playerRecords if c.jerseyNum === jerseyN} yield (c.name, c.score, c.active)
+  }
+
+  def setup = DBIO.seq(
+    playerRecords.schema.create,
+    playerRecords ++= Seq( // JDBC batch update
+                          (7, "Roethlisberger, Ben", 94.1f, true),
+                          (11, "Smith, Alex", 85.3f, true),
+                          (18, "Manning, Payton", 96.5f, false),
+                          (99, "Doe, John", 15f, false))
+  )
+
+  def queryPlayers(prelude: String) = {
+    println("\n  " +prelude)
+    println(
+      "│ Name                          │Scor│ Active │Jerseynum│\n" +
+      "├───────────────────────────────┼────┼────────┼─────────┤"
+    )
+    DBIO.seq(playerRecords.result.map(_.map {
+      case (jerseyN, name, score, active) =>
+        f"$name%32s $score ${(if (active) "" else "in") + "active"}%8s $jerseyN%8d"
+    }.foreach(println)))
+  }
+
+  // Definition of the PLAYERS table
+  class PlayerRecords(tag: Tag) extends Table[(Int, String, Float, Boolean)](tag, "PLAYER_RECORDS") {
+    def active = column[Boolean]("ACTIVE")
+    def jerseyNum = column[Int]("JERSEY_NUM", O.PrimaryKey)
+    def name = column[String]("NAME", SqlType("VARCHAR2(32)"))
+    def score = column[Float]("SCORE")
+
+    def * = (jerseyNum, name, score, active)
+  }
+
+  println(s"The pre-compiled parameterized update DML:\n${compiledUpdate(0).updateStatement}")
+
+  Await.result(db.run(
+    for { // Using the for comprehension
+    _ <- setup
+    _ <- queryPlayers("Before update:")
+    n <- compiledUpdate(99).update("Smith, Steve", 42f, true)
+    _ <- queryPlayers("After update:")
+  } yield n), Duration.Inf)
+
+}