Translate AVG/SUM/MIN/MAX

dotnet · Feb 22, 2019 · 65dbb6e · 65dbb6e
1 parent c2ec462
commit 65dbb6e
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Showing 5 changed files with 221 additions and 22 deletions.
diff --git a/src/EFCore.InMemory/Query/PipeLine/InMemoryQueryableMethodTranslatingExpressionVisitor.cs b/src/EFCore.InMemory/Query/PipeLine/InMemoryQueryableMethodTranslatingExpressionVisitor.cs
@@ -59,7 +59,7 @@ protected override ShapedQueryExpression TranslateAny(ShapedQueryExpression sour
             return source;
         }
 
-        protected override ShapedQueryExpression TranslateAverage(ShapedQueryExpression source, LambdaExpression selector)
+        protected override ShapedQueryExpression TranslateAverage(ShapedQueryExpression source, LambdaExpression selector, Type resultType)
             => TranslateScalarAggregate(source, selector, nameof(Enumerable.Average));
 
         protected override ShapedQueryExpression TranslateCast(ShapedQueryExpression source, Type resultType) => throw new NotImplementedException();
@@ -192,10 +192,10 @@ protected override ShapedQueryExpression TranslateLongCount(ShapedQueryExpressio
             return source;
         }
 
-        protected override ShapedQueryExpression TranslateMax(ShapedQueryExpression source, LambdaExpression selector)
+        protected override ShapedQueryExpression TranslateMax(ShapedQueryExpression source, LambdaExpression selector, Type resultType)
             => TranslateScalarAggregate(source, selector, nameof(Enumerable.Max));
 
-        protected override ShapedQueryExpression TranslateMin(ShapedQueryExpression source, LambdaExpression selector)
+        protected override ShapedQueryExpression TranslateMin(ShapedQueryExpression source, LambdaExpression selector, Type resultType)
             => TranslateScalarAggregate(source, selector, nameof(Enumerable.Min));
 
         protected override ShapedQueryExpression TranslateOfType(ShapedQueryExpression source, Type resultType) => throw new NotImplementedException();
@@ -269,7 +269,7 @@ protected override ShapedQueryExpression TranslateSkip(ShapedQueryExpression sou
 
         protected override ShapedQueryExpression TranslateSkipWhile(ShapedQueryExpression source, LambdaExpression predicate) => throw new NotImplementedException();
 
-        protected override ShapedQueryExpression TranslateSum(ShapedQueryExpression source, LambdaExpression selector)
+        protected override ShapedQueryExpression TranslateSum(ShapedQueryExpression source, LambdaExpression selector, Type resultType)
             => TranslateScalarAggregate(source, selector, nameof(Enumerable.Sum));
 
         protected override ShapedQueryExpression TranslateTake(ShapedQueryExpression source, Expression count)

diff --git a/src/EFCore.Relational/Query/PipeLine/QuerySqlGenerator.cs b/src/EFCore.Relational/Query/PipeLine/QuerySqlGenerator.cs
@@ -188,11 +188,20 @@ protected override Expression VisitTable(TableExpression tableExpression)
 
         protected override Expression VisitSqlBinary(SqlBinaryExpression sqlBinaryExpression)
         {
-            Visit(sqlBinaryExpression.Left);
-
-            _relationalCommandBuilder.Append(_operatorMap[sqlBinaryExpression.OperatorType]);
-
-            Visit(sqlBinaryExpression.Right);
+            if (sqlBinaryExpression.OperatorType == ExpressionType.Coalesce)
+            {
+                    _relationalCommandBuilder.Append("COALESCE(");
+                    Visit(sqlBinaryExpression.Left);
+                    _relationalCommandBuilder.Append(", ");
+                    Visit(sqlBinaryExpression.Right);
+                    _relationalCommandBuilder.Append(")");
+            }
+            else
+            {
+                Visit(sqlBinaryExpression.Left);
+                _relationalCommandBuilder.Append(_operatorMap[sqlBinaryExpression.OperatorType]);
+                Visit(sqlBinaryExpression.Right);
+            }
 
             return sqlBinaryExpression;
         }

diff --git a/...EFCore.Relational/Query/PipeLine/RelationalQueryableMethodTranslatingExpressionVisitor.cs b/...EFCore.Relational/Query/PipeLine/RelationalQueryableMethodTranslatingExpressionVisitor.cs
@@ -5,6 +5,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Linq.Expressions;
+using Microsoft.EntityFrameworkCore.Internal;
 using Microsoft.EntityFrameworkCore.Query.PipeLine;
 using Microsoft.EntityFrameworkCore.Relational.Query.PipeLine.SqlExpressions;
 using Microsoft.EntityFrameworkCore.Storage;
@@ -79,7 +80,57 @@ protected override ShapedQueryExpression TranslateAny(ShapedQueryExpression sour
             return source;
         }
 
-        protected override ShapedQueryExpression TranslateAverage(ShapedQueryExpression source, LambdaExpression selector) => throw new NotImplementedException();
+        protected override ShapedQueryExpression TranslateAverage(ShapedQueryExpression source, LambdaExpression selector, Type resultType)
+        {
+            if (selector != null)
+            {
+                source = TranslateSelect(source, selector);
+            }
+
+            var projection = (SqlExpression)((SelectExpression)source.QueryExpression)
+                .GetProjectionExpression(new ProjectionMember());
+
+            var inputType = projection.Type.UnwrapNullableType();
+            if (inputType == typeof(int)
+                || inputType == typeof(long))
+            {
+                projection = new SqlCastExpression(projection, typeof(double), _typeMappingSource.FindMapping(typeof(double)));
+            }
+
+            if (projection.Type.UnwrapNullableType() == typeof(float))
+            {
+                projection = new SqlCastExpression(
+                    new SqlFunctionExpression(
+                        null,
+                        "AVG",
+                        null,
+                        new[]
+                        {
+                            projection
+                        },
+                        typeof(double),
+                        _typeMappingSource.FindMapping(typeof(double)),
+                        false),
+                    projection.Type,
+                    projection.TypeMapping);
+            }
+            else
+            {
+                projection = new SqlFunctionExpression(
+                    null,
+                    "AVG",
+                    null,
+                    new[]
+                    {
+                        projection
+                    },
+                    projection.Type,
+                    projection.TypeMapping,
+                    false);
+            }
+
+            return AggregateResultShaper(source, projection, throwOnNullResult: true, resultType);
+        }
 
         protected override ShapedQueryExpression TranslateCast(ShapedQueryExpression source, Type resultType) => throw new NotImplementedException();
 
@@ -183,9 +234,55 @@ protected override ShapedQueryExpression TranslateLastOrDefault(ShapedQueryExpre
 
         protected override ShapedQueryExpression TranslateLongCount(ShapedQueryExpression source, LambdaExpression predicate) => throw new NotImplementedException();
 
-        protected override ShapedQueryExpression TranslateMax(ShapedQueryExpression source, LambdaExpression selector) => throw new NotImplementedException();
+        protected override ShapedQueryExpression TranslateMax(ShapedQueryExpression source, LambdaExpression selector, Type resultType)
+        {
+            if (selector != null)
+            {
+                source = TranslateSelect(source, selector);
+            }
+
+            var projection = (SqlExpression)((SelectExpression)source.QueryExpression)
+                .GetProjectionExpression(new ProjectionMember());
+
+            projection = new SqlFunctionExpression(
+                null,
+                "MAX",
+                null,
+                new[]
+                {
+                    projection
+                },
+                resultType,
+                projection.TypeMapping,
+                false);
+
+            return AggregateResultShaper(source, projection, throwOnNullResult: true, resultType);
+        }
+
+        protected override ShapedQueryExpression TranslateMin(ShapedQueryExpression source, LambdaExpression selector, Type resultType)
+        {
+            if (selector != null)
+            {
+                source = TranslateSelect(source, selector);
+            }
 
-        protected override ShapedQueryExpression TranslateMin(ShapedQueryExpression source, LambdaExpression selector) => throw new NotImplementedException();
+            var projection = (SqlExpression)((SelectExpression)source.QueryExpression)
+                .GetProjectionExpression(new ProjectionMember());
+
+            projection = new SqlFunctionExpression(
+                null,
+                "MIN",
+                null,
+                new[]
+                {
+                    projection
+                },
+                resultType,
+                projection.TypeMapping,
+                false);
+
+            return AggregateResultShaper(source, projection, throwOnNullResult: true, resultType);
+        }
 
         protected override ShapedQueryExpression TranslateOfType(ShapedQueryExpression source, Type resultType) => throw new NotImplementedException();
 
@@ -265,7 +362,51 @@ protected override ShapedQueryExpression TranslateSkip(ShapedQueryExpression sou
 
         protected override ShapedQueryExpression TranslateSkipWhile(ShapedQueryExpression source, LambdaExpression predicate) => throw new NotImplementedException();
 
-        protected override ShapedQueryExpression TranslateSum(ShapedQueryExpression source, LambdaExpression selector) => throw new NotImplementedException();
+        protected override ShapedQueryExpression TranslateSum(ShapedQueryExpression source, LambdaExpression selector, Type resultType)
+        {
+            if (selector != null)
+            {
+                source = TranslateSelect(source, selector);
+            }
+
+            var serverOutputType = resultType.UnwrapNullableType();
+            var projection = (SqlExpression)((SelectExpression)source.QueryExpression)
+                .GetProjectionExpression(new ProjectionMember());
+
+            if (serverOutputType == typeof(float))
+            {
+                projection = new SqlCastExpression(
+                    new SqlFunctionExpression(
+                        null,
+                        "SUM",
+                        null,
+                        new[]
+                        {
+                            projection
+                        },
+                        typeof(double),
+                        _typeMappingSource.FindMapping(typeof(double)),
+                        false),
+                    serverOutputType,
+                    projection.TypeMapping);
+            }
+            else
+            {
+                projection = new SqlFunctionExpression(
+                    null,
+                    "SUM",
+                    null,
+                    new[]
+                    {
+                        projection
+                    },
+                    serverOutputType,
+                    projection.TypeMapping,
+                    false);
+            }
+
+            return AggregateResultShaper(source, projection, throwOnNullResult: false, resultType);
+        }
 
         protected override ShapedQueryExpression TranslateTake(ShapedQueryExpression source, Expression count)
         {
@@ -331,5 +472,50 @@ private SqlExpression TranslateLambdaExpression(
 
             return TranslateExpression((SelectExpression)shapedQueryExpression.QueryExpression, lambdaBody, condition);
         }
+
+        private ShapedQueryExpression AggregateResultShaper(
+            ShapedQueryExpression source, Expression projection, bool throwOnNullResult, Type resultType)
+        {
+            var selectExpression = (SelectExpression)source.QueryExpression;
+            selectExpression.ApplyProjection(
+                new Dictionary<ProjectionMember, Expression>
+                {
+                    { new ProjectionMember(), projection }
+                });
+
+            Expression shaper = new ProjectionBindingExpression(selectExpression, new ProjectionMember(), projection.Type);
+
+            if (throwOnNullResult)
+            {
+                var resultVariable = Expression.Variable(projection.Type, "result");
+
+                shaper = Expression.Block(
+                    new[] { resultVariable },
+                    Expression.Assign(resultVariable, shaper),
+                    Expression.Condition(
+                        Expression.Equal(resultVariable, Expression.Default(projection.Type)),
+                        Expression.Throw(
+                            Expression.New(
+                                typeof(InvalidOperationException).GetConstructors()
+                                    .Single(ci => ci.GetParameters().Length == 1),
+                                Expression.Constant(RelationalStrings.NoElements)),
+                            projection.Type),
+                        resultVariable),
+                    resultType != resultVariable.Type
+                    ? Expression.Convert(resultVariable, resultType)
+                    : (Expression)resultVariable);
+            }
+            else if (resultType.IsNullableType())
+            {
+                shaper = Expression.Convert(shaper, resultType);
+            }
+
+            source.ShaperExpression
+                = Expression.Lambda(
+                    shaper,
+                    source.ShaperExpression.Parameters);
+
+            return source;
+        }
     }
 }
diff --git a/src/EFCore.Relational/Query/PipeLine/TypeMappingApplyingExpressionVisitor.cs b/src/EFCore.Relational/Query/PipeLine/TypeMappingApplyingExpressionVisitor.cs
@@ -71,7 +71,7 @@ protected virtual SqlExpression ApplyTypeMappingOnSqlCast(
         {
             if (typeMapping == null)
             {
-                throw new InvalidOperationException("TypeMapping should not be null.");
+                return sqlCastExpression;
             }
 
             var operand = ApplyTypeMapping(

diff --git a/src/EFCore/Query/PipeLine/QueryableMethodTranslatingExpressionVisitor.cs b/src/EFCore/Query/PipeLine/QueryableMethodTranslatingExpressionVisitor.cs
@@ -57,7 +57,8 @@ protected override Expression VisitMethodCall(MethodCallExpression methodCallExp
                                shapedQueryExpression,
                                methodCallExpression.Arguments.Count == 2
                                    ? UnwrapLambdaFromQuoteExpression(methodCallExpression.Arguments[1])
-                                   : null);
+                                   : null,
+                               methodCallExpression.Type);
 
                         case nameof(Queryable.Cast):
                             return TranslateCast(shapedQueryExpression, methodCallExpression.Method.GetGenericArguments()[0]);
@@ -268,15 +269,17 @@ protected override Expression VisitMethodCall(MethodCallExpression methodCallExp
                                shapedQueryExpression,
                                methodCallExpression.Arguments.Count == 2
                                    ? UnwrapLambdaFromQuoteExpression(methodCallExpression.Arguments[1])
-                                   : null);
+                                   : null,
+                               methodCallExpression.Type);
 
                         case nameof(Queryable.Min):
                             shapedQueryExpression.ResultType = ResultType.Single;
                             return TranslateMin(
                                shapedQueryExpression,
                                methodCallExpression.Arguments.Count == 2
                                    ? UnwrapLambdaFromQuoteExpression(methodCallExpression.Arguments[1])
-                                   : null);
+                                   : null,
+                               methodCallExpression.Type);
 
                         case nameof(Queryable.OfType):
                             return TranslateOfType(shapedQueryExpression, methodCallExpression.Method.GetGenericArguments()[0]);
@@ -349,7 +352,8 @@ protected override Expression VisitMethodCall(MethodCallExpression methodCallExp
                                shapedQueryExpression,
                                methodCallExpression.Arguments.Count == 2
                                    ? UnwrapLambdaFromQuoteExpression(methodCallExpression.Arguments[1])
-                                   : null);
+                                   : null,
+                               methodCallExpression.Type);
 
                         case nameof(Queryable.Take):
                             return TranslateTake(shapedQueryExpression, methodCallExpression.Arguments[1]);
@@ -409,7 +413,7 @@ private LambdaExpression UnwrapLambdaFromQuoteExpression(Expression expression)
 
         protected abstract ShapedQueryExpression TranslateAll(ShapedQueryExpression source, LambdaExpression predicate);
         protected abstract ShapedQueryExpression TranslateAny(ShapedQueryExpression source, LambdaExpression predicate);
-        protected abstract ShapedQueryExpression TranslateAverage(ShapedQueryExpression source, LambdaExpression selector);
+        protected abstract ShapedQueryExpression TranslateAverage(ShapedQueryExpression source, LambdaExpression selector, Type resultType);
         protected abstract ShapedQueryExpression TranslateCast(ShapedQueryExpression source, Type resultType);
         protected abstract ShapedQueryExpression TranslateConcat(ShapedQueryExpression source1, ShapedQueryExpression source2);
         protected abstract ShapedQueryExpression TranslateContains(ShapedQueryExpression source, Expression item);
@@ -425,8 +429,8 @@ private LambdaExpression UnwrapLambdaFromQuoteExpression(Expression expression)
         protected abstract ShapedQueryExpression TranslateJoin(ShapedQueryExpression outer, ShapedQueryExpression inner, LambdaExpression outerKeySelector, LambdaExpression innerKeySelector, LambdaExpression resultSelector);
         protected abstract ShapedQueryExpression TranslateLastOrDefault(ShapedQueryExpression source, LambdaExpression predicate, bool returnDefault);
         protected abstract ShapedQueryExpression TranslateLongCount(ShapedQueryExpression source, LambdaExpression predicate);
-        protected abstract ShapedQueryExpression TranslateMax(ShapedQueryExpression source, LambdaExpression selector);
-        protected abstract ShapedQueryExpression TranslateMin(ShapedQueryExpression source, LambdaExpression selector);
+        protected abstract ShapedQueryExpression TranslateMax(ShapedQueryExpression source, LambdaExpression selector, Type resultType);
+        protected abstract ShapedQueryExpression TranslateMin(ShapedQueryExpression source, LambdaExpression selector, Type resultType);
         protected abstract ShapedQueryExpression TranslateOfType(ShapedQueryExpression source, Type resultType);
         protected abstract ShapedQueryExpression TranslateOrderBy(ShapedQueryExpression source, LambdaExpression keySelector, bool ascending);
         protected abstract ShapedQueryExpression TranslateReverse(ShapedQueryExpression source);
@@ -436,7 +440,7 @@ private LambdaExpression UnwrapLambdaFromQuoteExpression(Expression expression)
         protected abstract ShapedQueryExpression TranslateSingleOrDefault(ShapedQueryExpression source, LambdaExpression predicate, bool returnDefault);
         protected abstract ShapedQueryExpression TranslateSkip(ShapedQueryExpression source, Expression count);
         protected abstract ShapedQueryExpression TranslateSkipWhile(ShapedQueryExpression source, LambdaExpression predicate);
-        protected abstract ShapedQueryExpression TranslateSum(ShapedQueryExpression source, LambdaExpression selector);
+        protected abstract ShapedQueryExpression TranslateSum(ShapedQueryExpression source, LambdaExpression selector, Type resultType);
         protected abstract ShapedQueryExpression TranslateTake(ShapedQueryExpression source, Expression count);
         protected abstract ShapedQueryExpression TranslateTakeWhile(ShapedQueryExpression source, LambdaExpression predicate);
         protected abstract ShapedQueryExpression TranslateThenBy(ShapedQueryExpression source, LambdaExpression keySelector, bool ascending);