Scala: Guide for Data Science Professionals

Operations on columns

In the previous section, you learned about the different invokers and how they mapped to SQL statements. We brushed over the methods supported by columns themselves, however: we can compare for equality using ===, but what other operations are supported by Slick columns?

Most of the SQL functions are supported. For instance, to get the total donations to candidates whose name starts with "O", we could run the following:

scala> db.withSession { implicit session =>
  Tables.transactions.filter { 
    _.candidate.startsWith("O") 
  }.take(5).list 
}
List[Tables.Transactions#TableElementType] = List(Transaction(Some(1594098)...

Similarly, to count donations that happened between January 1, 2011 and February 1, 2011, we can use the ...