Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Data.Linq/SqlClient/Query/SqlAliaser.cs

@@ -0,0 +1,52 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Data.Linq;
+
+namespace System.Data.Linq.SqlClient {
+    internal class SqlAliaser {
+        Visitor visitor;
+
+        internal SqlAliaser() {
+            this.visitor = new Visitor();
+        }
+
+        internal SqlNode AssociateColumnsWithAliases(SqlNode node) {
+            return this.visitor.Visit(node);
+        }
+
+        class Visitor : SqlVisitor {
+            SqlAlias alias;
+
+            internal Visitor() {
+            }
+            
+            internal override SqlAlias VisitAlias(SqlAlias sqlAlias) {
+                SqlAlias save = this.alias;
+                this.alias = sqlAlias;
+                sqlAlias.Node = this.Visit(sqlAlias.Node);
+                this.alias = save;
+                return sqlAlias;
+            }
+            
+            internal override SqlRow VisitRow(SqlRow row) {
+                foreach (SqlColumn c in row.Columns) {
+                    c.Alias = alias;
+                }
+                return base.VisitRow(row);
+            }
+            internal override SqlTable VisitTable(SqlTable tab) {
+                foreach (SqlColumn c in tab.Columns) {
+                    c.Alias = alias;
+                }
+                return base.VisitTable(tab);
+            }
+            internal override SqlExpression VisitTableValuedFunctionCall(SqlTableValuedFunctionCall fc) {
+                foreach (SqlColumn c in fc.Columns) {
+                    c.Alias = this.alias;
+                }
+                return base.VisitTableValuedFunctionCall(fc);
+            }
+        }
+    }
+}