CODEWITHSUNDEEP
scalaslick
thund
thund

Reputation: 1953

Slick query filter acting on arbitrary columns

Say I have a SQL table with columns x and y, each integer valued. I can do a Slick query to select for 5 <= x <= 10 like this:

val myQuery = TableQuery[MyXYTable]
myQuery.filter(p => p.x >= 5 && p.x <= 10)

Now suppose I want to simultaneously filter for 5 <= y <= 10 as well. I'd like to re-use my same filter logic, but this time apply it to the y column. Is there a way to do this in Slick? ie to write a filter function, and pass in an argument specifying which column it should filter? So I'd have something like:

myQuery.addFiveTenFilter(x-column).addFiveTenFilter(y-column)

If I was writing raw SQL this would be pretty trivial, but I can't see how to do it with Slick syntax.

Upvotes: 4

Views: 548

Answers (1)

jkinkead
jkinkead

Reputation: 4411

If you create a function of type Rep[Int] => Rep[Boolean], you can use it in a filter method and pass the column in:

// As a function literal.
val filterByFiveTen: (Rep[Int] => Rep[Boolean]) = { column =>
  column >= 5 && column <= 10
}
myQuery.filter(row => filterByFiveTen(row.xColumn))

// As a method.
def filterByFiveTen(column: Rep[Int]): Rep[Boolean] = {
  column >= 5 && column <= 10
}
myQuery.filter(row => filterByFiveTen(row.xColumn))

Upvotes: 1

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