Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Data/System/Data/Common/SchemaTableOptionalColumn.cs

@@ -0,0 +1,32 @@
+//------------------------------------------------------------------------------
+// <copyright file="SchemaTableOptionalColumn.cs" company="Microsoft">
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+// <owner current="true" primary="true">[....]</owner>
+//------------------------------------------------------------------------------
+
+namespace System.Data.Common {
+
+    // optional columns that DataAdapter.Fill(Schema) will pay attention to
+    // when constructing new DataColumns to add to a DataTable
+    public static class SchemaTableOptionalColumn {
+
+        public static readonly string ProviderSpecificDataType = "ProviderSpecificDataType";
+
+        public static readonly string IsAutoIncrement = "IsAutoIncrement";
+        public static readonly string IsHidden        = "IsHidden";
+        public static readonly string IsReadOnly      = "IsReadOnly";
+        public static readonly string IsRowVersion    = "IsRowVersion";
+        public static readonly string BaseServerName  = "BaseServerName";
+        public static readonly string BaseCatalogName = "BaseCatalogName";
+
+        public static readonly string AutoIncrementSeed = "AutoIncrementSeed";
+        public static readonly string AutoIncrementStep = "AutoIncrementStep";
+        public static readonly string DefaultValue      = "DefaultValue";
+        public static readonly string Expression        = "Expression";
+
+        public static readonly string BaseTableNamespace  = "BaseTableNamespace";
+        public static readonly string BaseColumnNamespace = "BaseColumnNamespace";
+        public static readonly string ColumnMapping       = "ColumnMapping";
+    }
+}