Don't run update if new values equal original

pmarflee · pmarflee · commit 7d7a5652c549 · 2014-03-23T16:35:35.000Z
Don't run update if new values equal original, and return zero for the
number of rows changed
diff --git a/Simple.Data.InMemoryTest/InMemoryTests.cs b/Simple.Data.InMemoryTest/InMemoryTests.cs
@@ -806,5 +806,21 @@ public void LeftJoinTest()
 
             Assert.AreEqual(3, actual.Count);
         }
+
+        [Test]
+        public void UpdateWithOriginalValuesRowsUpdatedShouldBeZeroIfNewValueAreSameAsOriginalValue()
+        {
+            var adapter = new InMemoryAdapter();
+            adapter.SetKeyColumn("Test", "Id");
+            Database.UseMockAdapter(adapter);
+            var db = Database.Open();
+            db.Test.Upsert(Id: 1, SomeValue: "Testing");
+            var record = db.Test.Get(1);
+            var record1 = record.Clone();
+
+            var rowsUpdated = db.Test.Update(record, record1);
+
+            Assert.AreEqual(0, rowsUpdated);
+        }
     }
 }
diff --git a/Simple.Data/DatabaseRunner.cs b/Simple.Data/DatabaseRunner.cs
@@ -44,6 +44,7 @@ internal override int Update(string tableName, IDictionary<string, object> newVa
         {
             SimpleExpression criteria = CreateCriteriaFromOriginalValues(tableName, newValuesDict, originalValuesDict);
             var changedValuesDict = CreateChangedValuesDict(newValuesDict, originalValuesDict);
+            if (changedValuesDict.Count == 0) return 0;
             return _adapter.Update(tableName, changedValuesDict, criteria);
         }
 
diff --git a/Simple.Data/TransactionRunner.cs b/Simple.Data/TransactionRunner.cs
@@ -96,6 +96,7 @@ internal override int Update(string tableName, IDictionary<string, object> newVa
         {
             SimpleExpression criteria = CreateCriteriaFromOriginalValues(tableName, newValuesDict, originalValuesDict);
             var changedValuesDict = CreateChangedValuesDict(newValuesDict, originalValuesDict);
+            if (changedValuesDict.Count == 0) return 0;
             return _adapter.Update(tableName, changedValuesDict, criteria, _adapterTransaction);
         }
 

Original file line number	Diff line number	Diff line change
`@@ -44,6 +44,7 @@ internal override int Update(string tableName, IDictionary<string, object> newVa`
`44`	`44`	`{`
`45`	`45`	`SimpleExpression criteria = CreateCriteriaFromOriginalValues(tableName, newValuesDict, originalValuesDict);`
`46`	`46`	`var changedValuesDict = CreateChangedValuesDict(newValuesDict, originalValuesDict);`
	`47`	`+ if (changedValuesDict.Count == 0) return 0;`
`47`	`48`	`return _adapter.Update(tableName, changedValuesDict, criteria);`
`48`	`49`	`}`
`49`	`50`
Original file line number	Diff line number	Diff line change
`@@ -96,6 +96,7 @@ internal override int Update(string tableName, IDictionary<string, object> newVa`
`96`	`96`	`{`
`97`	`97`	`SimpleExpression criteria = CreateCriteriaFromOriginalValues(tableName, newValuesDict, originalValuesDict);`
`98`	`98`	`var changedValuesDict = CreateChangedValuesDict(newValuesDict, originalValuesDict);`
	`99`	`+ if (changedValuesDict.Count == 0) return 0;`
`99`	`100`	`return _adapter.Update(tableName, changedValuesDict, criteria, _adapterTransaction);`
`100`	`101`	`}`
`101`	`102`