Add support for BelongsTo to SqlExpression

Author: mythz

src/ServiceStack.OrmLite/Expressions/SqlExpression.Join.cs

@@ -175,6 +175,29 @@ public string SelectInto<TModel>()
             {
                 var found = false;
 
+                if (fieldDef.BelongToModelName != null)
+                {
+                    var tableDef = orderedDefs.FirstOrDefault(x => x.Name == fieldDef.BelongToModelName);
+                    if (tableDef != null)
+                    {
+                        var matchingField = FindWeakMatch(tableDef, fieldDef);
+                        if (matchingField != null)
+                        {
+                            if (OnlyFields == null || OnlyFields.Contains(fieldDef.Name))
+                            {
+                                if (sbSelect.Length > 0)
+                                    sbSelect.Append(", ");
+
+                                sbSelect.AppendFormat("{0} as {1}",
+                                    DialectProvider.GetQuotedColumnName(tableDef, matchingField),
+                                    SqlColumn(fieldDef.Name));
+
+                                continue;
+                            }
+                        }
+                    }
+                }
+
                 foreach (var tableDef in orderedDefs)
                 {
                     foreach (var tableFieldDef in tableDef.FieldDefinitions)
@@ -184,7 +207,6 @@ public string SelectInto<TModel>()
                             if (OnlyFields != null && !OnlyFields.Contains(fieldDef.Name))
                                 continue;
 
-                            found = true;
                             if (sbSelect.Length > 0)
                                 sbSelect.Append(", ");
 
@@ -195,6 +217,7 @@ public string SelectInto<TModel>()
                             if (tableFieldDef.Alias != null)
                                 sbSelect.Append(" AS ").Append(SqlColumn(fieldDef.Name));
 
+                            found = true;
                             break;
                         }
                     }
@@ -208,11 +231,7 @@ public string SelectInto<TModel>()
                     // Add support for auto mapping `{Table}{Field}` convention
                     foreach (var tableDef in orderedDefs)
                     {
-                        var matchingField = tableDef.FieldDefinitions
-                            .FirstOrDefault(x =>
-                                string.Compare(tableDef.Name + x.Name, fieldDef.Name, StringComparison.OrdinalIgnoreCase) == 0
-                             || string.Compare(tableDef.ModelName + x.FieldName, fieldDef.Name, StringComparison.OrdinalIgnoreCase) == 0);
-
+                        var matchingField = FindWeakMatch(tableDef, fieldDef);
                         if (matchingField != null)
                         {
                             if (OnlyFields != null && !OnlyFields.Contains(fieldDef.Name))
@@ -237,6 +256,14 @@ public string SelectInto<TModel>()
             return ToSelectStatement();
         }
 
+        private static FieldDefinition FindWeakMatch(ModelDefinition tableDef, FieldDefinition fieldDef)
+        {
+            return tableDef.FieldDefinitions
+                .FirstOrDefault(x =>
+                    string.Compare(tableDef.Name + x.Name, fieldDef.Name, StringComparison.OrdinalIgnoreCase) == 0
+                    || string.Compare(tableDef.ModelName + x.FieldName, fieldDef.Name, StringComparison.OrdinalIgnoreCase) == 0);
+        }
+
         public virtual SqlExpression<T> Where<Target>(Expression<Func<Target, bool>> predicate)
         {
             AppendToWhere("AND", predicate);

tests/ServiceStack.OrmLite.Tests/Issues/BelongsToIssue.cs

@@ -0,0 +1,66 @@
+using NUnit.Framework;
+using ServiceStack.DataAnnotations;
+using ServiceStack.Text;
+
+namespace ServiceStack.OrmLite.Tests.Issues
+{
+    class A
+    {
+        public int Id { get; set; }
+        public string SomeAProperty { get; set; }
+    }
+    class B
+    {
+        public int Id { get; set; }
+        public string SomeBProperty { get; set; }
+        public int AId { get; set; }
+    }
+    class C
+    {
+        public int Id { get; set; }
+        public string SomeCProperty { get; set; }
+        public int BId { get; set; }
+    }
+    class D
+    {
+        public int Id { get; set; }
+
+        [BelongTo(typeof(B))]
+        public int BId { get; set; }
+
+        public int CId { get; set; }
+
+        public string SomeAProperty { get; set; }
+        public string SomeBProperty { get; set; }
+        public string SomeCProperty { get; set; }
+    }
+
+    public class BelongsToIssue : OrmLiteTestBase
+    {
+        [Test]
+        public void Does_use_BelongsTo_to_specify_Attribute()
+        {
+            using (var db = OpenDbConnection())
+            {
+                db.DropAndCreateTable<A>();
+                db.DropAndCreateTable<B>();
+                db.DropAndCreateTable<C>();
+
+                db.Insert(new A { Id = 1, SomeAProperty = "A1" });
+                db.Insert(new A { Id = 2, SomeAProperty = "A2" });
+                db.Insert(new A { Id = 3, SomeAProperty = "A3" });
+                db.Insert(new B { Id = 10, SomeBProperty = "B1", AId = 1 });
+                db.Insert(new B { Id = 11, SomeBProperty = "B2", AId = 2 });
+                db.Insert(new C { Id = 20, SomeCProperty = "C", BId = 10 });
+
+                var q = db.From<A>()
+                    .Join<B>()
+                    .LeftJoin<B,C>();
+
+                var results = db.Select<D>(q);
+                Assert.That(results.Count, Is.EqualTo(2));
+                Assert.That(results.Map(x => x.BId), Is.EquivalentTo(new[] { 10, 11 }));
+            }
+        }
+    }
+}

tests/ServiceStack.OrmLite.Tests/ServiceStack.OrmLite.Tests.csproj

@@ -129,6 +129,7 @@
     <Compile Include="DateTimeOffsetTests.cs" />
     <Compile Include="DateTimeTests.cs" />
     <Compile Include="DefaultValueTests.cs" />
+    <Compile Include="Issues\BelongsToIssue.cs" />
     <Compile Include="UseCase\ExpressionsAuthorTests.cs" />
     <Compile Include="Expression\ComplexJoinTests.cs" />
     <Compile Include="Expression\ExpressionUsingCustomSerializedEnumTests.cs" />