calasql-core_2.13.0.1.9.source-code.Aggregatable.scala Maven / Gradle / Ivy
package scalasql.core
/**
* Something that supports aggregate operations. Most commonly a [[Select]], but
* also could be a [[Aggregatable.Proxy]]
*/
trait Aggregatable[Q] extends WithSqlExpr[Q] {
def aggregateExpr[V: TypeMapper](f: Q => Context => SqlStr)(
implicit qr: Queryable.Row[Expr[V], V]
): Expr[V]
}
object Aggregatable {
/**
* A reference that aggregations for usage within [[Select.aggregate]], to allow
* the caller to perform multiple aggregations within a single query.
*/
class Proxy[Q](val expr: Q) extends Aggregatable[Q] {
def aggregateExpr[V: TypeMapper](f: Q => Context => SqlStr)(
implicit qr: Queryable.Row[Expr[V], V]
): Expr[V] = { Expr[V] { implicit c => f(expr)(c) } }
}
}