handle sql variable type (#1333)

* handle sql variable type

* comments

src/Microsoft.SqlTools.ServiceLayer/Localization/sr.cs

@@ -8631,6 +8631,11 @@ namespace Microsoft.SqlTools.ServiceLayer
             return Keys.GetString(Keys.QueryServiceQueryFailed, message);
         }
 
+        public static string QueryServiceUnsupportedSqlVariantType(string underlyingType, string columnName)
+        {
+            return Keys.GetString(Keys.QueryServiceUnsupportedSqlVariantType, underlyingType, columnName);
+        }
+
         public static string QueryServiceSaveAsFail(string fileName, string message)
         {
             return Keys.GetString(Keys.QueryServiceSaveAsFail, fileName, message);
@@ -9021,6 +9026,9 @@ namespace Microsoft.SqlTools.ServiceLayer
             public const string QueryServiceResultSetTooLarge = "QueryServiceResultSetTooLarge";
 
 
+            public const string QueryServiceUnsupportedSqlVariantType = "QueryServiceUnsupportedSqlVariantType";
+
+
             public const string QueryServiceSaveAsResultSetNotComplete = "QueryServiceSaveAsResultSetNotComplete";
 
 

src/Microsoft.SqlTools.ServiceLayer/Localization/sr.resx

@@ -303,6 +303,11 @@
     <value>Result set has too many rows to be safely loaded</value>
     <comment></comment>
   </data>
+  <data name="QueryServiceUnsupportedSqlVariantType" xml:space="preserve">
+    <value>The underlying type &quot;{0}&quot; for sql variant column &quot;{1}&quot; could not be resolved.</value>
+    <comment>.
+ Parameters: 0 - underlyingType (string), 1 - columnName (string) </comment>
+  </data>
   <data name="QueryServiceSaveAsResultSetNotComplete" xml:space="preserve">
     <value>Result cannot be saved until query execution has completed</value>
     <comment></comment>

src/Microsoft.SqlTools.ServiceLayer/Localization/sr.strings

@@ -124,6 +124,8 @@ QueryServiceResultSetHasNoResults = Query has no results to return
 
 QueryServiceResultSetTooLarge = Result set has too many rows to be safely loaded
 
+QueryServiceUnsupportedSqlVariantType(string underlyingType, string columnName) = The underlying type "{0}" for sql variant column "{1}" could not be resolved.
+
 ### Save As Requests
 
 QueryServiceSaveAsResultSetNotComplete = Result cannot be saved until query execution has completed

src/Microsoft.SqlTools.ServiceLayer/Localization/sr.xlf

@@ -5708,6 +5708,12 @@
         <note>.
  Parameters: 0 - error (String) </note>
       </trans-unit>
+      <trans-unit id="QueryServiceUnsupportedSqlVariantType">
+        <source>The underlying type "{0}" for sql variant column "{1}" could not be resolved.</source>
+        <target state="new">The underlying type "{0}" for sql variant column "{1}" could not be resolved.</target>
+        <note>.
+ Parameters: 0 - underlyingType (string), 1 - columnName (string) </note>
+      </trans-unit>
     </body>
   </file>
 </xliff>

src/Microsoft.SqlTools.ServiceLayer/QueryExecution/DataStorage/ServiceBufferFileStreamReader.cs

@@ -134,14 +134,15 @@ namespace Microsoft.SqlTools.ServiceLayer.QueryExecution.DataStorage
                         continue;
                     }
 
-                    // The typename is stored in the string
+                    // We need to specify the assembly name for SQL types in order to resolve the type correctly.
-                    colType = Type.GetType(sqlVariantType);
+                    if (sqlVariantType.StartsWith("System.Data.SqlTypes."))
-
-                    // Workaround .NET bug, see sqlbu# 440643 and vswhidbey# 599834
-                    // TODO: Is this workaround necessary for .NET Core?
-                    if (colType == null && sqlVariantType == "System.Data.SqlTypes.SqlSingle")
                     {
-                        colType = typeof(SqlSingle);
+                        sqlVariantType = sqlVariantType + ", System.Data.Common";
+                    }
+                    colType = Type.GetType(sqlVariantType);
+                    if (colType == null)
+                    {
+                        throw new ArgumentException(SR.QueryServiceUnsupportedSqlVariantType(sqlVariantType, column.ColumnName));
                     }
                 }
                 else