Add support for selecting and ordering CustomSelect fields

Author: mythz

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

@@ -297,7 +297,7 @@ public string SelectInto<TModel>()
                                 {
                                     sbSelect.Append(GetQuotedColumnName(tableDef, tableFieldDef.Name));
 
-                                    if (tableFieldDef.Alias != null)
+                                    if (tableFieldDef.RequiresAlias)
                                         sbSelect.Append(" AS ").Append(SqlColumn(fieldDef.Name));
                                 }
                                 else

src/ServiceStack.OrmLite/Expressions/SqlExpression.cs

@@ -192,6 +192,8 @@ internal virtual SqlExpression<T> Select(string[] fields, bool distinct)
                         foreach (var fieldDef in tableDef.FieldDefinitionsArray)
                         {
                             var qualifiedField = GetQuotedColumnName(tableDef, fieldDef.Name);
+                            if (fieldDef.CustomSelect != null)
+                                qualifiedField += " AS " + fieldDef.Name;
 
                             if (sb.Length > 0)
                                 sb.Append(", ");
@@ -200,21 +202,25 @@ internal virtual SqlExpression<T> Select(string[] fields, bool distinct)
                             fieldsList.Add(fieldDef.Name);
                         }
                     }
-                    continue;
                 }
-
-                fieldsList.Add(field); //Could be non-matching referenced property
-
-                var match = FirstMatchingField(field);
-                if (match == null)
-                    continue;
-
-                var qualifiedName = GetQuotedColumnName(match.Item1, match.Item2.Name);
-
-                if (sb.Length > 0)
-                    sb.Append(", ");
-
-                sb.Append(qualifiedName);
+                else
+                {
+                    fieldsList.Add(field); //Could be non-matching referenced property
+    
+                    var match = FirstMatchingField(field);
+                    if (match == null)
+                        continue;
+    
+                    var fieldDef = match.Item2;
+                    var qualifiedName = GetQuotedColumnName(match.Item1, fieldDef.Name);
+                    if (fieldDef.CustomSelect != null)
+                        qualifiedName += " AS " + fieldDef.Name;
+    
+                    if (sb.Length > 0)
+                        sb.Append(", ");
+    
+                    sb.Append(qualifiedName);
+                }
             }
 
             UnsafeSelect(StringBuilderCache.ReturnAndFree(sb), distinct:distinct);
@@ -2135,7 +2141,10 @@ protected virtual string GetQuotedColumnName(ModelDefinition tableDef, string me
                     tableDef = this.ModelDef;
                 }
 
-                var includePrefix = PrefixFieldWithTableName && fd?.CustomSelect == null && !tableDef.ModelType.IsInterface;
+                if (fd?.CustomSelect != null)
+                    return fd.CustomSelect;
+
+                var includePrefix = PrefixFieldWithTableName && !tableDef.ModelType.IsInterface;
                 return includePrefix
                     ? DialectProvider.GetQuotedColumnName(tableDef, fieldName)
                     : DialectProvider.GetQuotedColumnName(fieldName);

src/ServiceStack.OrmLite/FieldDefinition.cs

@@ -57,7 +57,7 @@ public class FieldDefinition
         public string CheckConstraint { get; set; }
 
         public bool IsUniqueConstraint { get; set; }
-
+        
         public ForeignKeyConstraint ForeignKey { get; set; }
 
         public GetMemberDelegate GetValueFn { get; set; }
@@ -90,6 +90,8 @@ public string GetQuotedValue(object fromInstance, IOrmLiteDialectProvider dialec
 
         public string CustomSelect { get; set; }
 
+        public bool RequiresAlias => Alias != null || CustomSelect != null;
+
         public string BelongToModelName { get; set; }
 
         public bool IsReference { get; set; }

tests/ServiceStack.OrmLite.Tests/AutoQueryTests.cs

@@ -3,6 +3,7 @@
 using System.Linq;
 using System.Text;
 using NUnit.Framework;
+using NUnit.Framework.Internal;
 using ServiceStack.DataAnnotations;
 using ServiceStack.Text;
 
@@ -483,7 +484,56 @@ public void Can_query_Rockstars_with_Distinct_Fields()
                 Assert.That(results.Count(x => x.FirstName == "Michael"), Is.EqualTo(1));
             }
         }
+        
+        public class FeatureRequest
+        {
+            public int Id { get; set; }
+            public int Up { get; set; }
+            public int Down { get; set; }
+            [CustomSelect("up - down")]
+            public int Points { get; set; }
+        }
+
+        [Test]
+        public void Can_select_custom_select_column()
+        {
+            using (var db = OpenDbConnection())
+            {
+                db.DropAndCreateTable<FeatureRequest>();
 
+                3.Times(i => db.Insert(new FeatureRequest {Id = i + 1, Up = (i + 1) * 2, Down = i + 1}));
+
+                var q = db.From<FeatureRequest>()
+                    .Select(new[]{ "id", "up", "down", "points" });
+
+                var results = db.Select(q);
+                
+                results.PrintDump();
+
+                Assert.That(results.Map(x => x.Points), Is.EqualTo(new[]{ 1, 2, 3 }));
+            }
+        }
+
+        [Test]
+        public void Can_order_by_custom_select_column()
+        {
+            using (var db = OpenDbConnection())
+            {
+                db.DropAndCreateTable<FeatureRequest>();
+
+                3.Times(i => db.Insert(new FeatureRequest {Id = i + 1, Up = (i + 1) * 2, Down = i + 1}));
+
+                var q = db.From<FeatureRequest>()
+                    .Select(new[]{ "id", "up", "down", "points" })
+                    .OrderByDescending(x => x.Points);
+
+                var results = db.Select(q);
+                
+                results.PrintDump();
+
+                Assert.That(results.Map(x => x.Points), Is.EqualTo(new[]{ 3, 2, 1 }));
+            }
+        }
     }
 
 }

tests/ServiceStack.OrmLite.Tests/CustomSqlExpressionTests.cs

@@ -125,7 +125,7 @@ protected override Object GetMemberExpression(MemberExpression m)
             return base.GetMemberExpression(m);
         }
 
-        protected override string GetQuotedColumnName(ModelDefinition tableDef, String memberName)
+        protected override string GetQuotedColumnName(ModelDefinition tableDef, string memberName)
         {
             if (useFieldName)
             {
@@ -151,7 +151,7 @@ private ModelDefinition GetCurrentTableDef(ModelDefinition tableDef, string memb
             var nonInheritedProperties = GetCurrentPropertiesWithoutBase(tableDef);
             while (curType != null && !nonInheritedProperties.Contains(memberName))
             {
-                curType = curType.BaseType();
+                curType = curType.BaseType;
                 nonInheritedProperties = GetCurrentPropertiesWithoutBase(curType?.GetModelMetadata());
             }