Subqueries

Author: Revolucent

CoreDataQueryInterface/Miscellanea.swift

@@ -29,14 +29,14 @@ public func alias(_ expression: KeyPathExpressionConvertible, type: NSAttributeT
     return alias(expression, name: expression.cdqiName, type: type)
 }
 
-public func subquery<E: EntityAttribute>(_ items: E, _ query: (E) -> NSPredicate) -> ExpressionConvertible where E: KeyPathExpressionConvertible {
+public func subquery<E: EntityAttribute>(_ items: E, _ query: (E) -> NSPredicate) -> ExpressionConvertible where E: ExpressionConvertible {
     let uuid = NSUUID().uuidString
     let index = uuid.index(uuid.startIndex, offsetBy: 6)
     let randomString = uuid.substring(to: index)
     let variable = "v\(randomString)"
     return NSExpression(forSubquery: items.cdqiExpression, usingIteratorVariable: variable, predicate: query(E(variable: variable)))
 }
 
-public func subqueryCount<E: EntityAttribute>(_ items: E, _ query: (E) -> NSPredicate) -> FunctionExpression where E: KeyPathExpressionConvertible {
+public func subqueryCount<E: EntityAttribute>(_ items: E, _ query: (E) -> NSPredicate) -> FunctionExpression where E: ExpressionConvertible {
     return count(subquery(items, query))
 }

CoreDataQueryInterfaceTests/FilterTests.swift

@@ -86,14 +86,14 @@ class FilterTests : BaseTestCase {
         XCTAssertEqual(highSalaryCount, 17)
     }
 
-//    func testNumberOfDepartmentsWithEmployeesWhoseLastNamesStartWithSUsingSubquery() {
-//        let departmentCount = try! managedObjectContext.from(Department).filter{ department in
-//            department.employees.subquery {
-//                some($0.lastName.beginsWith("S", options: .CaseInsensitivePredicateOption))
-//            }.cdqiCount() > 0
-//        }.count()
-//        XCTAssertEqual(departmentCount, 2)
-//    }
+    func testNumberOfDepartmentsWithEmployeesWhoseLastNamesStartWithSUsingSubquery() {
+        let departmentCount = try! managedObjectContext.from(Department.self).filter{ department in
+            subquery(department.employees) { (employee: EmployeeAttribute) in
+                some(employee.lastName.cdqiBeginsWith("S", options: .caseInsensitive))
+            }.cdqiCount() > 0
+        }.count()
+        XCTAssertEqual(departmentCount, 2)
+    }
 
     func testNumberOfDepartmentsWithNoSalariesLessThanOrEqualTo() {
         let departmentCount = try! managedObjectContext.from(Department.self).filter {