JoinNullable deserialisation fix

docs/reference.md

@@ -9838,6 +9838,32 @@ db.run(Enclosing.select) ==> Seq(value1, value2)
 
 
 
+### DataTypes.JoinNullable proper type mapping
+
+
+
+```scala
+case class A[T[_]](id: T[Int], bId: T[Option[Int]])
+object A extends Table[A]
+
+object Custom extends Enumeration {
+  val Foo, Bar = Value
+
+  implicit def make: String => Value = withName
+}
+
+case class B[T[_]](id: T[Int], custom: T[Custom.Value])
+object B extends Table[B]
+db.run(A.insert.columns(_.id := 1, _.bId := None))
+val result = db.run(A.select.leftJoin(B)(_.id === _.id).single)
+result._2 ==> None
+```
+
+
+
+
+
+
 ## Optional
 Queries using columns that may be `NULL`, `Expr[Option[T]]` or `Option[T]` in Scala
 ### Optional

scalasql/core/src/Queryable.scala

@@ -68,6 +68,14 @@ object Queryable {
     var nulls = 0
     var nonNulls = 0
 
+    def consumeNulls(columnsCount: Int): Boolean = {
+      val result = Range.inclusive(index + 1, index + columnsCount).forall { i =>
+        r.getObject(i) == null
+      }
+      if (result) index = index + columnsCount
+      result
+    }
+
     def get[T](mt: TypeMapper[T]) = {
       index += 1
       val res = mt.get(r, index)
@@ -143,10 +151,11 @@ object Queryable {
       def walkExprs(q: JoinNullable[Q]) = qr.walkExprs(q.get)
 
       def construct(args: Queryable.ResultSetIterator): Option[R] = {
-        val startNonNulls = args.nonNulls
-        val res = qr.construct(args)
-        if (startNonNulls == args.nonNulls) None
-        else Option(res)
+        if (args.consumeNulls(qr.walkLabels().length)) {
+          None
+        } else {
+          Option(qr.construct(args))
+        }
       }
 
       def deconstruct(r: Option[R]): JoinNullable[Q] = JoinNullable(qr.deconstruct(r.get))

scalasql/src/dialects/Dialect.scala

@@ -228,8 +228,7 @@ trait Dialect extends DialectTypeMappers {
     def jdbcType: JDBCType = JDBCType.VARCHAR
     def get(r: ResultSet, idx: Int): T = {
       val str = r.getString(idx)
-      if (str == null) null.asInstanceOf[T]
-      else constructor(str)
+      constructor(str)
     }
     def put(r: PreparedStatement, idx: Int, v: T) =
       r.setObject(idx, v, java.sql.Types.OTHER)

scalasql/test/resources/h2-customer-schema.sql

@@ -3,6 +3,8 @@ DROP TABLE IF EXISTS product CASCADE;
 DROP TABLE IF EXISTS shipping_info CASCADE;
 DROP TABLE IF EXISTS purchase CASCADE;
 DROP TABLE IF EXISTS data_types CASCADE;
+DROP TABLE IF EXISTS a CASCADE;
+DROP TABLE IF EXISTS b CASCADE;
 DROP TABLE IF EXISTS non_round_trip_types CASCADE;
 DROP TABLE IF EXISTS opt_cols CASCADE;
 DROP TABLE IF EXISTS nested CASCADE;
@@ -58,6 +60,16 @@ CREATE TABLE data_types (
 --     my_offset_time TIME WITH TIME ZONE,
 );
 
+CREATE TABLE a(
+    id INTEGER,
+    b_id INTEGER
+);
+
+CREATE TABLE b(
+    id INTEGER,
+    custom VARCHAR(256)
+);
+
 CREATE TABLE non_round_trip_types(
     my_zoned_date_time TIMESTAMP WITH TIME ZONE,
     my_offset_date_time TIMESTAMP WITH TIME ZONE

scalasql/test/resources/mysql-customer-schema.sql

@@ -4,6 +4,8 @@ DROP TABLE IF EXISTS `product` CASCADE;
 DROP TABLE IF EXISTS `shipping_info` CASCADE;
 DROP TABLE IF EXISTS `purchase` CASCADE;
 DROP TABLE IF EXISTS `data_types` CASCADE;
+DROP TABLE IF EXISTS `a` CASCADE;
+DROP TABLE IF EXISTS `b` CASCADE;
 DROP TABLE IF EXISTS `non_round_trip_types` CASCADE;
 DROP TABLE IF EXISTS `opt_cols` CASCADE;
 DROP TABLE IF EXISTS `nested` CASCADE;
@@ -57,6 +59,16 @@ CREATE TABLE data_types (
     my_enum ENUM ('foo', 'bar', 'baz')
 );
 
+CREATE TABLE a(
+    id INTEGER,
+    b_id INTEGER
+);
+
+CREATE TABLE b(
+    id INTEGER,
+    custom VARCHAR(256)
+);
+
 CREATE TABLE non_round_trip_types(
     my_zoned_date_time TIMESTAMP,
     my_offset_date_time TIMESTAMP

scalasql/test/resources/postgres-customer-schema.sql

@@ -3,6 +3,8 @@ DROP TABLE IF EXISTS product CASCADE;
 DROP TABLE IF EXISTS shipping_info CASCADE;
 DROP TABLE IF EXISTS purchase CASCADE;
 DROP TABLE IF EXISTS data_types CASCADE;
+DROP TABLE IF EXISTS a CASCADE;
+DROP TABLE IF EXISTS b CASCADE;
 DROP TABLE IF EXISTS non_round_trip_types CASCADE;
 DROP TABLE IF EXISTS opt_cols CASCADE;
 DROP TABLE IF EXISTS nested CASCADE;
@@ -61,6 +63,16 @@ CREATE TABLE data_types (
 
 );
 
+CREATE TABLE a(
+    id INTEGER,
+    b_id INTEGER
+);
+
+CREATE TABLE b(
+    id INTEGER,
+    custom VARCHAR(256)
+);
+
 CREATE TABLE non_round_trip_types(
     my_zoned_date_time TIMESTAMP WITH TIME ZONE,
     my_offset_date_time TIMESTAMP WITH TIME ZONE

scalasql/test/resources/sqlite-customer-schema.sql

@@ -3,6 +3,8 @@ DROP TABLE IF EXISTS product;
 DROP TABLE IF EXISTS shipping_info;
 DROP TABLE IF EXISTS purchase;
 DROP TABLE IF EXISTS data_types;
+DROP TABLE IF EXISTS a;
+DROP TABLE IF EXISTS b;
 DROP TABLE IF EXISTS non_round_trip_types;
 DROP TABLE IF EXISTS nested;
 DROP TABLE IF EXISTS enclosing;
@@ -56,6 +58,16 @@ CREATE TABLE data_types (
 --     my_offset_time TIME WITH TIME ZONE,
 );
 
+CREATE TABLE a(
+    id INTEGER,
+    b_id INTEGER
+);
+
+CREATE TABLE b(
+    id INTEGER,
+    custom VARCHAR(256)
+);
+
 CREATE TABLE non_round_trip_types(
     my_zoned_date_time TIMESTAMP,
     my_offset_date_time TIMESTAMP

scalasql/test/src/datatypes/DataTypesTests.scala

@@ -212,5 +212,24 @@ trait DataTypesTests extends ScalaSqlSuite {
 
       }
     )
+    test("JoinNullable proper type mapping") - checker.recorded(
+      "",
+      Text {
+        case class A[T[_]](id: T[Int], bId: T[Option[Int]])
+        object A extends Table[A]
+
+        object Custom extends Enumeration {
+          val Foo, Bar = Value
+
+          implicit def make: String => Value = withName
+        }
+
+        case class B[T[_]](id: T[Int], custom: T[Custom.Value])
+        object B extends Table[B]
+        db.run(A.insert.columns(_.id := 1, _.bId := None))
+        val result = db.run(A.select.leftJoin(B)(_.id === _.id).single)
+        result._2 ==> None
+      }
+    )
   }
 }