Handle subquery alias as source for defined values in join

MarkMpn.Sql4Cds.Engine.Tests/AdoProviderTests.cs

@@ -1608,6 +1608,77 @@ DECLARE @json NVARCHAR(4000) = N'{
             }
         }
 
+        [TestMethod]
+        public void OpenJsonDefaultSchemaDataTypes()
+        {
+            using (var con = new Sql4CdsConnection(_localDataSource))
+            using (var cmd = con.CreateCommand())
+            {
+                cmd.CommandText = @"
+DECLARE @json NVARCHAR(2048) = N'{
+   ""String_value"": ""John"",
+   ""DoublePrecisionFloatingPoint_value"": 45,
+   ""DoublePrecisionFloatingPoint_value"": 2.3456,
+   ""BooleanTrue_value"": true,
+   ""BooleanFalse_value"": false,
+   ""Null_value"": null,
+   ""Array_value"": [""a"",""r"",""r"",""a"",""y""],
+   ""Object_value"": {""obj"":""ect""}
+}';
+
+SELECT * FROM OpenJson(@json);";
+
+                using (var reader = cmd.ExecuteReader())
+                {
+                    Assert.AreEqual("key", reader.GetName(0));
+                    Assert.AreEqual("value", reader.GetName(1));
+                    Assert.AreEqual("type", reader.GetName(2));
+
+                    Assert.IsTrue(reader.Read());
+                    Assert.AreEqual("String_value", reader.GetString(0));
+                    Assert.AreEqual("John", reader.GetString(1));
+                    Assert.AreEqual(1, reader.GetInt32(2));
+
+                    Assert.IsTrue(reader.Read());
+                    Assert.AreEqual("DoublePrecisionFloatingPoint_value", reader.GetString(0));
+                    Assert.AreEqual("45", reader.GetString(1));
+                    Assert.AreEqual(2, reader.GetInt32(2));
+
+                    Assert.IsTrue(reader.Read());
+                    Assert.AreEqual("DoublePrecisionFloatingPoint_value", reader.GetString(0));
+                    Assert.AreEqual("2.3456", reader.GetString(1));
+                    Assert.AreEqual(2, reader.GetInt32(2));
+
+                    Assert.IsTrue(reader.Read());
+                    Assert.AreEqual("BooleanTrue_value", reader.GetString(0));
+                    Assert.AreEqual("true", reader.GetString(1));
+                    Assert.AreEqual(3, reader.GetInt32(2));
+
+                    Assert.IsTrue(reader.Read());
+                    Assert.AreEqual("BooleanFalse_value", reader.GetString(0));
+                    Assert.AreEqual("false", reader.GetString(1));
+                    Assert.AreEqual(3, reader.GetInt32(2));
+
+                    Assert.IsTrue(reader.Read());
+                    Assert.AreEqual("Null_value", reader.GetString(0));
+                    Assert.IsTrue(reader.IsDBNull(1));
+                    Assert.AreEqual(0, reader.GetInt32(2));
+
+                    Assert.IsTrue(reader.Read());
+                    Assert.AreEqual("Array_value", reader.GetString(0));
+                    Assert.AreEqual("[\"a\",\"r\",\"r\",\"a\",\"y\"]", reader.GetString(1));
+                    Assert.AreEqual(4, reader.GetInt32(2));
+
+                    Assert.IsTrue(reader.Read());
+                    Assert.AreEqual("Object_value", reader.GetString(0));
+                    Assert.AreEqual("{\"obj\":\"ect\"}", reader.GetString(1));
+                    Assert.AreEqual(5, reader.GetInt32(2));
+
+                    Assert.IsFalse(reader.Read());
+                }
+            }
+        }
+
         [TestMethod]
         public void OpenJsonExplicitSchema()
         {
@@ -1682,5 +1753,51 @@ [Order]  NVARCHAR(MAX)  AS JSON
                 }
             }
         }
+
+        [TestMethod]
+        public void MergeJson()
+        {
+            using (var con = new Sql4CdsConnection(_localDataSource))
+            using (var cmd = con.CreateCommand())
+            {
+                cmd.CommandText = @"
+DECLARE @json1 NVARCHAR(MAX),@json2 NVARCHAR(MAX)
+
+SET @json1=N'{""name"": ""John"", ""surname"":""Doe""}'
+
+SET @json2=N'{""name"": ""John"", ""age"":45}'
+
+SELECT *
+FROM OPENJSON(@json1)
+UNION ALL
+SELECT *
+FROM OPENJSON(@json2)
+WHERE [key] NOT IN (SELECT [key] FROM OPENJSON(@json1))";
+
+                using (var reader = cmd.ExecuteReader())
+                {
+                    Assert.AreEqual("key", reader.GetName(0));
+                    Assert.AreEqual("value", reader.GetName(1));
+                    Assert.AreEqual("type", reader.GetName(2));
+
+                    Assert.IsTrue(reader.Read());
+                    Assert.AreEqual("name", reader.GetString(0));
+                    Assert.AreEqual("John", reader.GetString(1));
+                    Assert.AreEqual(1, reader.GetInt32(2));
+
+                    Assert.IsTrue(reader.Read());
+                    Assert.AreEqual("surname", reader.GetString(0));
+                    Assert.AreEqual("Doe", reader.GetString(1));
+                    Assert.AreEqual(1, reader.GetInt32(2));
+
+                    Assert.IsTrue(reader.Read());
+                    Assert.AreEqual("age", reader.GetString(0));
+                    Assert.AreEqual("45", reader.GetString(1));
+                    Assert.AreEqual(2, reader.GetInt32(2));
+
+                    Assert.IsFalse(reader.Read());
+                }
+            }
+        }
     }
 }

MarkMpn.Sql4Cds.Engine/ExecutionPlan/BaseJoinNode.cs

@@ -112,6 +112,18 @@ protected Entity Merge(Entity leftEntity, INodeSchema leftSchema, Entity rightEn
             return merged;
         }
 
+        protected void FoldDefinedValues(INodeSchema rightSchema)
+        {
+            foreach (var kvp in DefinedValues.ToList())
+            {
+                if (!rightSchema.ContainsColumn(kvp.Value, out var innerColumn))
+                    throw new NotSupportedQueryFragmentException($"Unknown defined column '{kvp.Value}'");
+
+                if (innerColumn != kvp.Value)
+                    DefinedValues[kvp.Key] = innerColumn;
+            }
+        }
+
         public override IEnumerable<IExecutionPlanNode> GetSources()
         {
             yield return LeftSource;
@@ -172,7 +184,10 @@ protected virtual INodeSchema GetSchema(NodeCompilationContext context, bool inc
             }
 
             foreach (var definedValue in DefinedValues)
-                schema[definedValue.Key] = innerSchema.Schema[definedValue.Value];
+            {
+                innerSchema.ContainsColumn(definedValue.Value, out var innerColumn);
+                schema[definedValue.Key] = innerSchema.Schema[innerColumn];
+            }
 
             _lastLeftSchema = outerSchema;
             _lastRightSchema = innerSchema;

MarkMpn.Sql4Cds.Engine/ExecutionPlan/FoldableJoinNode.cs

@@ -56,11 +56,14 @@ public override IDataExecutionPlanNodeInternal FoldQuery(NodeCompilationContext
             RightSource = RightSource.FoldQuery(context, hints);
             RightSource.Parent = this;
 
+            var leftSchema = LeftSource.GetSchema(context);
+            var rightSchema = RightSource.GetSchema(context);
+
+            FoldDefinedValues(rightSchema);
+
             if (SemiJoin)
                 return this;
 
-            var leftSchema = LeftSource.GetSchema(context);
-            var rightSchema = RightSource.GetSchema(context);
             var leftFilter = JoinType == QualifiedJoinType.Inner || JoinType == QualifiedJoinType.LeftOuter ? LeftSource as FilterNode : null;
             var rightFilter = JoinType == QualifiedJoinType.Inner || JoinType == QualifiedJoinType.RightOuter ? RightSource as FilterNode : null;
             var leftFetch = (leftFilter?.Source ?? LeftSource) as FetchXmlScan;
@@ -685,9 +688,12 @@ public override void AddRequiredColumns(NodeCompilationContext context, IList<st
 
             var leftColumns = requiredColumns
                 .Where(col => leftSchema.ContainsColumn(col, out _))
+                .Distinct()
                 .ToList();
             var rightColumns = requiredColumns
                 .Where(col => rightSchema.ContainsColumn(col, out _))
+                .Concat(DefinedValues.Values)
+                .Distinct()
                 .ToList();
 
             if (LeftAttribute != null)

MarkMpn.Sql4Cds.Engine/ExecutionPlan/NestedLoopNode.cs

@@ -180,9 +180,12 @@ public override IDataExecutionPlanNodeInternal FoldQuery(NodeCompilationContext
 
             var innerParameterTypes = GetInnerParameterTypes(leftSchema, context.ParameterTypes);
             var innerContext = new NodeCompilationContext(context.DataSources, context.Options, innerParameterTypes, context.Log);
+            var rightSchema = RightSource.GetSchema(innerContext);
             RightSource = RightSource.FoldQuery(innerContext, hints);
             RightSource.Parent = this;
 
+            FoldDefinedValues(rightSchema);
+
             if (LeftSource is ConstantScanNode constant &&
                 constant.Schema.Count == 0 &&
                 constant.Values.Count == 1 &&