Fixed hash joins with keys of different types

MarkMpn · Mar 8, 2022 · 8a2f028 · 8a2f028
1 parent 6911749
commit 8a2f028
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Showing 2 changed files with 29 additions and 7 deletions.
diff --git a/MarkMpn.Sql4Cds.Engine/ExecutionPlan/HashJoinNode.cs b/MarkMpn.Sql4Cds.Engine/ExecutionPlan/HashJoinNode.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Data.SqlTypes;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
@@ -31,10 +32,20 @@ protected override IEnumerable<Entity> ExecuteInternal(IDictionary<string, DataS
             // Build the hash table
             var leftSchema = LeftSource.GetSchema(dataSources, parameterTypes);
             leftSchema.ContainsColumn(LeftAttribute.GetColumnName(), out var leftCol);
+            var leftColType = leftSchema.Schema[leftCol].ToNetType(out _);
+            var rightSchema = RightSource.GetSchema(dataSources, parameterTypes);
+            rightSchema.ContainsColumn(RightAttribute.GetColumnName(), out var rightCol);
+            var rightColType = rightSchema.Schema[rightCol].ToNetType(out _);
+
+            if (!SqlTypeConverter.CanMakeConsistentTypes(leftColType, rightColType, out var keyType))
+                throw new QueryExecutionException($"Cannot match key types {leftColType.Name} and {rightColType.Name}");
+
+            var leftKeyConverter = SqlTypeConverter.GetConversion(leftColType, keyType);
+            var rightKeyConverter = SqlTypeConverter.GetConversion(rightColType, keyType);
 
             foreach (var entity in LeftSource.Execute(dataSources, options, parameterTypes, parameterValues))
             {
-                var key = entity[leftCol];
+                var key = leftKeyConverter(entity[leftCol]);
 
                 if (!_hashTable.TryGetValue(key, out var list))
                 {
@@ -46,12 +57,9 @@ protected override IEnumerable<Entity> ExecuteInternal(IDictionary<string, DataS
             }
 
             // Probe the hash table using the right source
-            var rightSchema = RightSource.GetSchema(dataSources, parameterTypes);
-            rightSchema.ContainsColumn(RightAttribute.GetColumnName(), out var rightCol);
-
             foreach (var entity in RightSource.Execute(dataSources, options, parameterTypes, parameterValues))
             {
-                var key = entity[rightCol];
+                var key = rightKeyConverter(entity[rightCol]);
                 var matched = false;
 
                 if (_hashTable.TryGetValue(key, out var list))

diff --git a/MarkMpn.Sql4Cds.Engine/ExecutionPlan/SqlTypeConverter.cs b/MarkMpn.Sql4Cds.Engine/ExecutionPlan/SqlTypeConverter.cs
@@ -860,13 +860,27 @@ public static object ChangeType(object value, Type type)
             if (value != null && value.GetType() == type)
                 return value;
 
-            var key = value.GetType().FullName + " -> " + type.FullName;
-            var conversion = _conversions.GetOrAdd(key, _ => CompileConversion(value.GetType(), type));
+            var conversion = GetConversion(value.GetType(), type);
             return conversion(value);
         }
 
+        /// <summary>
+        /// Gets a function to convert from one type to another
+        /// </summary>
+        /// <param name="sourceType">The type to convert from</param>
+        /// <param name="destType">The type to convert to</param>
+        /// <returns>A function that converts between the requested types</returns>
+        public static Func<object, object> GetConversion(Type sourceType, Type destType)
+        {
+            var key = sourceType.FullName + " -> " + destType.FullName;
+            return _conversions.GetOrAdd(key, _ => CompileConversion(sourceType, destType));
+        }
+
         private static Func<object, object> CompileConversion(Type sourceType, Type destType)
         {
+            if (sourceType == destType)
+                return (object value) => value;
+
             var param = Expression.Parameter(typeof(object));
             var expression = (Expression) Expression.Convert(param, sourceType);