Merge pull request #309 from yoosoopov/patch-1

Avoid parameter sniffing for exists subquery

Author: ahmad-moussawi

QueryBuilder.Tests/DefineTest.cs

@@ -306,7 +306,7 @@ public void Test_Define_WhereExists()
             );
 
             var c = Compile(query);
-            Assert.Equal("SELECT * FROM [Customers] WHERE EXISTS (SELECT TOP (1) 1 FROM [Orders] WHERE [ShipPostalCode] = '8200')", c[EngineCodes.SqlServer]);
+            Assert.Equal("SELECT * FROM [Customers] WHERE EXISTS (SELECT 1 FROM [Orders] WHERE [ShipPostalCode] = '8200')", c[EngineCodes.SqlServer]);
         }
 
 

QueryBuilder.Tests/SqlServer/NestedSelectTests.cs

@@ -56,7 +56,7 @@ public void SqlCompile_QueryLimitAndNestedLimit_BindingValue()
             // var q = new Query().From("Foo").Where("C", "c").WhereExists(n).Where("A", "a");
 
             var actual = compiler.Compile(q).ToString();
-            Assert.Contains("SELECT * FROM [Foo] WHERE [x] = true AND NOT EXISTS (SELECT TOP (1) 1 FROM [Bar])",
+            Assert.Contains("SELECT * FROM [Foo] WHERE [x] = true AND NOT EXISTS (SELECT 1 FROM [Bar])",
                 actual);
             // Assert.Contains("SELECT * FROM [Foo] WHERE [C] = 'c' AND EXISTS (SELECT TOP (1) 1 FROM [Bar]) AND [A] = 'a'", actual);
         }

QueryBuilder/Base.Where.cs

@@ -527,8 +527,7 @@ public Q WhereExists(Query query)
 
             // remove unneeded components
             query = query.Clone().ClearComponent("select")
-                .SelectRaw("1")
-                .Limit(1);
+                .SelectRaw("1");
 
             return AddComponent("where", new ExistsCondition
             {
@@ -690,4 +689,4 @@ public Q OrWhereNotTime(string column, object value)
         #endregion
 
     }
-}
+}