Merge ISqlExpression and ISelectableExpression together

Author: mythz

src/ServiceStack.OrmLite/Expressions/ReadConnectionExtensions.cs

@@ -114,13 +114,21 @@ public static List<T> Select<T>(this IDbConnection dbConn, SqlExpression<T> expr
             return dbConn.Exec(dbCmd => dbCmd.Select(expression));
         }
 
+        /// <summary>
+        /// Project results from a number of joined tables into a different model
+        /// </summary>
+        public static List<Into> Select<Into, From>(this IDbConnection dbConn, Func<SqlExpression<From>, SqlExpression<From>> expression)
+        {
+            return dbConn.Exec(dbCmd => dbCmd.Select<Into, From>(expression));
+        }
+
         /// <summary>
         /// Returns results from using an SqlExpression lambda. E.g:
         /// <para>db.Select(db.From&lt;Person&gt;().Where(x =&gt; x.Age &gt; 40))</para>
         /// </summary>
         public static List<T> Select<T>(this IDbConnection dbConn, ISqlExpression expression, object anonType = null)
         {
-            return dbConn.Exec(dbCmd => dbCmd.SqlList<T>(expression.ToSelectStatement(), anonType));
+            return dbConn.Exec(dbCmd => dbCmd.SqlList<T>(expression.SelectInto<T>(), anonType));
         }
 
         /// <summary>

src/ServiceStack.OrmLite/Expressions/ReadExtensions.cs

@@ -21,6 +21,14 @@ internal static List<T> Select<T>(this IDbCommand dbCmd, Func<SqlExpression<T>,
             return dbCmd.ExprConvertToList<T>(sql);
         }
 
+        internal static List<Into> Select<Into, From>(this IDbCommand dbCmd, Func<SqlExpression<From>, SqlExpression<From>> expression)
+        {
+            var expr = OrmLiteConfig.DialectProvider.SqlExpression<From>();
+            string sql = expression(expr).SelectInto<Into>();
+
+            return dbCmd.ExprConvertToList<Into>(sql);
+        }
+
         internal static List<T> Select<T>(this IDbCommand dbCmd, SqlExpression<T> expression)
         {
             string sql = expression.SelectInto<T>();
@@ -31,7 +39,7 @@ internal static List<T> Select<T>(this IDbCommand dbCmd, SqlExpression<T> expres
         internal static List<T> Select<T>(this IDbCommand dbCmd, Expression<Func<T, bool>> predicate)
         {
             var expr = OrmLiteConfig.DialectProvider.SqlExpression<T>();
-            string sql = expr.Where(predicate).ToSelectStatement();
+            string sql = expr.Where(predicate).SelectInto<T>();
 
             return dbCmd.ExprConvertToList<T>(sql);
         }
@@ -51,7 +59,7 @@ internal static T Single<T>(this IDbCommand dbCmd, Expression<Func<T, bool>> pre
 
         internal static T Single<T>(this IDbCommand dbCmd, SqlExpression<T> expression)
         {
-            string sql = expression.Limit(1).ToSelectStatement();
+            string sql = expression.Limit(1).SelectInto<T>();
 
             return dbCmd.ExprConvertTo<T>(sql);
         }
@@ -60,7 +68,7 @@ public static TKey Scalar<T, TKey>(this IDbCommand dbCmd, Expression<Func<T, TKe
         {
             var ev = OrmLiteConfig.DialectProvider.SqlExpression<T>();
             ev.Select(field);
-            var sql = ev.ToSelectStatement();
+            var sql = ev.SelectInto<T>();
             return dbCmd.Scalar<TKey>(sql);
         }
 
@@ -69,7 +77,7 @@ internal static TKey Scalar<T, TKey>(this IDbCommand dbCmd,
         {
             var ev = OrmLiteConfig.DialectProvider.SqlExpression<T>();
             ev.Select(field).Where(predicate);
-            string sql = ev.ToSelectStatement();
+            string sql = ev.SelectInto<T>();
             return dbCmd.Scalar<TKey>(sql);
         }
 

src/ServiceStack.OrmLite/Expressions/SqlExpression.cs

@@ -132,12 +132,6 @@ public virtual SqlExpression<T> From(string tables)
             return this;
         }
 
-        public virtual SqlExpression<T> From<Table>()
-        {
-            FromExpression = " \nFROM " + OrmLiteConfig.DialectProvider.GetQuotedTableName(typeof(Table).GetModelDefinition());
-            return this;
-        }
-
         public virtual SqlExpression<T> Where()
         {
             if (underlyingExpression != null) underlyingExpression = null; //Where() clears the expression
@@ -1353,10 +1347,6 @@ protected virtual object VisitColumnAccessMethod(MethodCallExpression m)
     public interface ISqlExpression
     {
         string ToSelectStatement();
-    }
-
-    public interface ISelectableSqlExpression
-    {
         string SelectInto<TModel>();
     }
 

src/ServiceStack.OrmLite/SqlBuilder.cs

@@ -219,6 +219,11 @@ public string ToSelectStatement()
             {
                 return RawSql;
             }
+
+            public string SelectInto<T>()
+            {
+                return RawSql;
+            }
         }
 
         public Template AddTemplate(string sql, object parameters = null)