Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Data.Entity/System/Data/SqlClient/SqlGen/TopClause.cs

@@ -0,0 +1,107 @@
+//---------------------------------------------------------------------
+// <copyright file="TopClause.cs" company="Microsoft">
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//
+// @owner  [....]
+// @backupOwner [....]
+//---------------------------------------------------------------------
+
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Globalization;
+using System.IO;
+using System.Text;
+using System.Data.SqlClient;
+using System.Data.Metadata.Edm;
+using System.Data.Common.CommandTrees;
+
+namespace System.Data.SqlClient.SqlGen
+{
+    /// <summary>
+    /// TopClause represents the a TOP expression in a SqlSelectStatement. 
+    /// It has a count property, which indicates how many TOP rows should be selected and a 
+    /// boolen WithTies property.
+    /// </summary>
+    class TopClause : ISqlFragment
+    {
+        ISqlFragment topCount;
+        bool withTies;
+
+        /// <summary>
+        /// Do we need to add a WITH_TIES to the top statement
+        /// </summary>
+        internal bool WithTies
+        {
+            get { return withTies; }
+        }
+
+        /// <summary>
+        /// How many top rows should be selected.
+        /// </summary>
+        internal ISqlFragment TopCount
+        {
+            get { return topCount; }
+        }
+
+        /// <summary>
+        /// Creates a TopClause with the given topCount and withTies.
+        /// </summary>
+        /// <param name="topCount"></param>
+        /// <param name="withTies"></param>
+        internal TopClause(ISqlFragment topCount, bool withTies)
+        {
+            this.topCount = topCount;
+            this.withTies = withTies;
+        }
+
+        /// <summary>
+        /// Creates a TopClause with the given topCount and withTies.
+        /// </summary>
+        /// <param name="topCount"></param>
+        /// <param name="withTies"></param>
+        internal TopClause(int topCount, bool withTies)
+        {
+            SqlBuilder sqlBuilder = new SqlBuilder();
+            sqlBuilder.Append(topCount.ToString(CultureInfo.InvariantCulture));
+            this.topCount = sqlBuilder;
+            this.withTies = withTies;
+        }
+
+        #region ISqlFragment Members
+
+        /// <summary>
+        /// Write out the TOP part of sql select statement 
+        /// It basically writes TOP (X) [WITH TIES].
+        /// The brackets around X are ommited for Sql8.
+        /// </summary>
+        /// <param name="writer"></param>
+        /// <param name="sqlGenerator"></param>
+        public void WriteSql(SqlWriter writer, SqlGenerator sqlGenerator)
+        {
+            writer.Write("TOP ");
+
+            if (sqlGenerator.SqlVersion != SqlVersion.Sql8)
+            {
+                writer.Write("(");
+            }
+
+            this.TopCount.WriteSql(writer, sqlGenerator);
+
+            if (sqlGenerator.SqlVersion != SqlVersion.Sql8)
+            {
+                writer.Write(")");
+            }
+
+            writer.Write(" ");
+
+            if (this.WithTies)
+            {
+                writer.Write("WITH TIES ");
+            }
+        }
+
+        #endregion
+    }
+}