Add support for specifying and selecting typed join aliases

Author: mythz

src/ServiceStack.OrmLite.SqlServer/SqlServerTableHint.cs

@@ -2,7 +2,7 @@
 {
     public class SqlServerTableHint
     {
-        public static JoinFormatDelegate ReadUncommitted = (table,expr) => "{0} WITH (READUNCOMMITTED) {1}".Fmt(table, expr);
+        public static JoinFormatDelegate ReadUncommitted = (table, expr) => "{0} WITH (READUNCOMMITTED) {1}".Fmt(table, expr);
         public static JoinFormatDelegate ReadCommitted = (table, expr) => "{0} WITH (READCOMMITTED) {1}".Fmt(table, expr);
         public static JoinFormatDelegate ReadPast = (table, expr) => "{0} WITH (READPAST) {1}".Fmt(table, expr);
         public static JoinFormatDelegate Serializable = (table, expr) => "{0} WITH (SERIALIZABLE) {1}".Fmt(table, expr);

src/ServiceStack.OrmLite.Sqlite/SqliteExpression.cs

@@ -49,7 +49,7 @@ protected override object VisitSqlMethodCall(MethodCallExpression m)
                     statement = string.Format("{0} DESC", quotedColName);
                     break;
                 case "As":
-                    statement = string.Format("{0} As {1}", quotedColName,
+                    statement = string.Format("{0} AS {1}", quotedColName,
                         base.DialectProvider.GetQuotedColumnName(RemoveQuoteFromAlias(args[0].ToString())));
                     break;
                 case "Sum":
@@ -66,7 +66,7 @@ protected override object VisitSqlMethodCall(MethodCallExpression m)
                     statement = string.Format("COUNT(DISTINCT {0})", quotedColName);
                     break;
                 default:
-                    throw new NotSupportedException();
+                    return base.VisitSqlMethodCall(m);
             }
 
             return new PartialSqlString(statement);

src/ServiceStack.OrmLite/Expressions/Sql.cs

@@ -102,6 +102,16 @@ public static string Avg(string value)
         {
             return "AVG({0})".Fmt(value);
         }
+
+        public static T AllFields<T>(T item)
+        {
+            return item;
+        }
+
+        public static string JoinAlias<T>(T property, string tableAlias)
+        {
+            return tableAlias;
+        }
     }
 
 }

src/ServiceStack.OrmLite/Expressions/SqlExpression.cs

@@ -1612,7 +1612,7 @@ private object SetAnonTypePropertyNamesForSelectExpression(object expr, Expressi
             var methodCallExpr = arg as MethodCallExpression;
             var mi = methodCallExpr != null ? methodCallExpr.Method : null;
             var declareType = mi != null && mi.DeclaringType != null ? mi.DeclaringType : null;
-            if (declareType != null && declareType.Name == "Sql" && mi.Name != "Desc" && mi.Name != "Asc" && mi.Name != "As") 
+            if (declareType != null && declareType.Name == "Sql" && mi.Name != "Desc" && mi.Name != "Asc" && mi.Name != "As" && mi.Name != "AllFields") 
                 return new PartialSqlString(expr + " AS " + member.Name); // new { Count = Sql.Count("*") }
 
             return expr;
@@ -2028,6 +2028,13 @@ protected virtual object VisitSqlMethodCall(MethodCallExpression m)
                 case "CountDistinct":
                     statement = string.Format("COUNT(DISTINCT {0})", quotedColName);
                     break;
+                case "AllFields":
+                    var argDef = m.Arguments[0].Type.GetModelMetadata();
+                    statement = DialectProvider.GetQuotedTableName(argDef) + ".*";
+                    break;
+                case "JoinAlias":
+                    statement = args[0] + "." + quotedColName.ToString().RightPart('.');
+                    break;
                 default:
                     throw new NotSupportedException();
             }

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

@@ -106,21 +106,19 @@ public void Can_use_cusom_SqlExpression_to_add_multiple_self_Left_Joins()
                 Assert.That(sales.Count, Is.EqualTo(1));
 
                 //Alternative
-                db.GetLastSql().Print();
                 q = db.From<Sale>()
                     .LeftJoin<ContactIssue>((s,c) => s.SellerId == c.Id, db.JoinAlias<ContactIssue>("seller"))
                     .LeftJoin<ContactIssue>((s,c) => s.BuyerId == c.Id, db.JoinAlias<ContactIssue>("buyer"))
-                    .Select(@"Sale.*
-                        , buyer.{0} AS BuyerFirstName
-                        , buyer.{1} AS BuyerLastName
-                        , seller.{0} AS SellerFirstName
-                        , seller.{1} AS SellerLastName"
-                    .Fmt("FirstName".SqlColumn(), "LastName".SqlColumn()));
+                    .Select<Sale, ContactIssue>((s,c) => new {
+                        sale = Sql.AllFields(s),
+                        BuyerFirstName = Sql.JoinAlias(c.FirstName, "buyer"),
+                        BuyerLastName = Sql.JoinAlias(c.LastName, "buyer"),
+                        SellerFirstName = Sql.JoinAlias(c.FirstName, "seller"),
+                        SellerLastName = Sql.JoinAlias(c.LastName, "seller"),
+                    });
 
                 q.Where(x => x.TenantId == tenantId);
 
-                q.ToSelectStatement().Print();
-
                 sales = db.Select<SaleView>(q);
                 Assert.That(sales.Count, Is.EqualTo(1));