notInSubQuery functionality (#791)

exposed-core/src/main/kotlin/org/jetbrains/exposed/sql/Op.kt

@@ -122,6 +122,14 @@ class InSubQueryOp<T>(val expr: Expression<T>, val query: Query): Op<Boolean>()
     }
 }
 
+class NotInSubQueryOp<T>(val expr: Expression<T>, val query: Query) : Op<Boolean>() {
+    override fun toQueryBuilder(queryBuilder: QueryBuilder) = queryBuilder {
+        append(expr, " NOT IN (")
+        query.prepareSQL(this)
+        +")"
+    }
+}
+
 class QueryParameter<T>(val value: T, val sqlType: IColumnType) : Expression<T>() {
     override fun toQueryBuilder(queryBuilder: QueryBuilder) = queryBuilder { registerArgument(sqlType, value) }
 }

exposed-core/src/main/kotlin/org/jetbrains/exposed/sql/SQLExpressionBuilder.kt

@@ -190,6 +190,8 @@ object SqlExpressionBuilder {
 
     infix fun<T> ExpressionWithColumnType<T>.inSubQuery(query: Query): Op<Boolean> = InSubQueryOp(this, query)
 
+    infix fun <T> ExpressionWithColumnType<T>.notInSubQuery(query: Query): Op<Boolean> = NotInSubQueryOp(this, query)
+
     @Suppress("UNCHECKED_CAST")
     fun<T, S: T?> ExpressionWithColumnType<S>.asLiteral(value: T) = when (value) {
         is Boolean -> booleanLiteral(value)

exposed-tests/src/test/kotlin/org/jetbrains/exposed/sql/tests/shared/dml/SelectTests.kt

@@ -5,6 +5,7 @@ import org.jetbrains.exposed.sql.*
 import org.jetbrains.exposed.sql.tests.DatabaseTestsBase
 import org.jetbrains.exposed.sql.tests.shared.assertEquals
 import org.junit.Test
+import kotlin.test.assertNull
 
 class SelectTests : DatabaseTestsBase() {
     // select expressions
@@ -74,7 +75,6 @@ class SelectTests : DatabaseTestsBase() {
     }
 
 
-
     @Test
     fun testInList01() {
         withCitiesAndUsers { cities, users, userData ->
@@ -104,6 +104,28 @@ class SelectTests : DatabaseTestsBase() {
         }
     }
 
+    @Test
+    fun testNotInSubQueryNoData() {
+        withCitiesAndUsers { cities, _, _ ->
+            val r = cities.select { cities.id notInSubQuery cities.slice(cities.id).selectAll() }
+            // no data since all ids are selected
+            assertEquals(0, r.count())
+        }
+    }
+
+    @Test
+    fun testNotInSubQuery() {
+        withCitiesAndUsers { cities, _, _ ->
+            val cityId = 2
+            val r = cities.select { cities.id notInSubQuery cities.slice(cities.id).select { cities.id eq cityId } }.map { it[cities.id] }.sorted()
+            assertEquals(2, r.size)
+            // only 2 cities with id 1 and 2 respectively
+            assertEquals(1, r[0])
+            assertEquals(3, r[1])
+            //there is no city with id=2
+            assertNull(r.find { it == cityId })
+        }
+    }
 
     @Test
     fun testSelectDistinct() {