ROOP - radical object oriented programming - fetching data from jdbc

roop.scala

// before

case class Query(table: String, orderKey: String, whereClause: Option[String] = None) {
  def fetchQuery(): String = {
    Seq(
      s"SELECT * FROM $table",
      whereClause.map(w => s"WHERE $w").getOrElse(""),
      s"ORDER BY $orderKey ASC"
    ).mkString
  }

  def countQuery(): String = {
    Seq(
      s"SELECT count(*) AS rowcount FROM $table",
      whereClause.map(w => s"WHERE $w").getOrElse("")
    ).mkString
  }
}

def foobar() {
  Query q = Query("", "")
  statement.execute(q.fetchQuery())
}


// AFTER
case class Query(table: String, orderKey: String, whereClause: Option[String] = None) {

  private fetchQuery(): String = {
    Seq(
      s"SELECT * FROM $table",
      whereClause.map(w => s"WHERE $w").getOrElse(""),
      s"ORDER BY $orderKey ASC"
    ).mkString
  }

  private countQuery(): String = {
    Seq(
      s"SELECT count(*) AS rowcount FROM $table",
      whereClause.map(w => s"WHERE $w").getOrElse("")
    ).mkString
  }

  def rowCount(statement: Statement): Long = {
    try {
      val countSet = statement.executeQuery(countQuery())
      try {
        countSet.next()
        countSet.getLong("rowcount")
      } finally {
        countSet.close()
      }
    }
  }

  def resultSet(statement: Statement): ResultSet = {
    // execute query and return
  }
}


def foobar() {
  Query q = Query("", "")
  q.fetchQuery(statement);
}