Play Framework 2.0 correct way to represent a set in a query using Anorm

问题

I am trying to return a list of results using Anorm using a query that returns matching rows for a set of ids. Eg.

select *
from example
where id in (1,2,3,4,5)

If I try

SQL(
    """
      select *
      from example 
      where id in ({ids})
    """
  ).on('ids -> ids).as(int("id") ~ str("name") *)

where ids is the String "1,2,3,4,5" it will only return the first row. What is the correct way to inject the set of ids?

回答1:

There's no simple way of doing it AFAIK.

This is how I solved it:

def findSomething(ids: String) = {
  // Split up the comma separated values
  val sids = ids split ","
  // Create a list of keys (id0, id1, id2, ...)
  val keys = for ( i <- 0 until sids.size ) yield ("id" + i)
  // Create a seq of parameterized values
  val values = sids map (toParameterValue(_))

  // Now zip together the keys and values into list of tuples
  val params = keys zip values

  DB.withConnection { implicit connection =>
    SQL(
      """
        select *
        from example 
        where id in ({%s})
      """.format(keys.mkString("},{"))
    ).on(
      params: _*
    ).as(
      int("id") ~ str("name") *
    )
  }
}

NB
The cruical part here is the string formatting in the SQL statement. It is vulnerable for SQL injection if you don't have total control of your input parameters.

来源：https://stackoverflow.com/questions/15864564/play-framework-2-0-correct-way-to-represent-a-set-in-a-query-using-anorm