Simple select with max using scalike jdbc

Question

Still trying to get familiar with scalikejdbc. What is the simplest way to just use sql syntax to send a query using scalike jdbc into a table to get max date? Something really simple like the below works fine but gives me an error when I try to add max around the column.

  val maxDate: Option[String] = DB readOnly { implicit session =>
    sql"select <column> from <table>"
      .map(rs => rs.string("<column")).first.apply()
  }

this does not work:

val maxDate: Option[String] = DB readOnly { implicit session =>
    sql"select max(<column>) from <table>"
      .map(rs => rs.string("<column")).first.apply()
  }

error: Failed to retrieve value because The column name not found.. If you're using SQLInterpolation,...

Expressions like `max(...)` either don't have a column name or alias, or get one derived from the expression itself, your assumption that it would somehow inherit the name of the column used inside the expression, is - at least for most DBMS I know - wrong. — Mark Rotteveel, Jan 27 '18 at 14:27

score 0 · Answer 1 · answered Jan 27 '18 at 14:16

I expect this happens because column max(MyColumn) does not have name "MyColumn" by default. You may try something like this instead

  val maxDate: Option[String] = DB readOnly { implicit session =>
    sql"select max(MyColumn) as MyColumn_max from MyTable"
      .map(rs => rs.string("MyColumn_max")).first.apply()
  }

Simple select with max using scalike jdbc

1 Answers1