Add HasChanges() to Snapshot<T> for efficient change detection

src/NPoco.Abstractions/Snapshotter.cs

@@ -83,6 +83,19 @@ public List<Change> Changes()
             return list;
         }
 
+        public bool HasChanges()
+        {
+            foreach (var pocoColumn in _originalValues)
+            {
+                var newValue = pocoColumn.Key.GetColumnValue(_pocoData, _trackedObject);
+                if (!AreEqual(pocoColumn.Value, newValue))
+                {
+                    return true;
+                }
+            }
+            return false;
+        }
+
         private bool AreEqual(object first, object second)
         {
             if (first == null && second == null) return true;

test/NPoco.Tests/SnapshotterTests.cs

@@ -1,7 +1,6 @@
 using System;
 using Microsoft.Data.SqlClient;
 using System.Linq;
-using NPoco;
 using NPoco.FluentMappings;
 using NPoco.Tests.Common;
 using NUnit.Framework;
@@ -148,6 +147,32 @@ public void GetDiffIncludingLists()
             Assert.AreEqual(1, snap.UpdatedColumns().Count);
             Assert.AreEqual("Values", snap.UpdatedColumns()[0]);
         }
+
+        [Test]
+        public void HasChangesShouldReturnFalseWhenNoChanges()
+        {
+            var user = new Admin { UserId = 1 };
+            var snap = _database.StartSnapshot(user);
+            Assert.False(snap.HasChanges());
+        }
+
+        [Test]
+        public void HasChangesShouldReturnTrueWhenPropertyChanged()
+        {
+            var user = new Admin { UserId = 1, Age = 30 };
+            var snap = _database.StartSnapshot(user);
+            user.Age = 31;
+            Assert.True(snap.HasChanges());
+        }
+
+        [Test]
+        public void HasChangesShouldMatchChangesCountBehavior()
+        {
+            var user = new Admin { UserId = 1, Age = 30 };
+            var snap = _database.StartSnapshot(user);
+            user.Age = 31;
+            Assert.AreEqual(snap.Changes().Any(), snap.HasChanges());
+        }
     }
 
     public class SnapshotOnClass