SqlBulkCopy: Explicitly state column name that mismatches(#3170)

Author: JNjenga

src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SqlBulkCopy.cs

@@ -572,6 +572,8 @@ private string AnalyzeTargetAndCreateUpdateBulkCommand(BulkCopySimpleResultSet i
                     if ((_localColumnMappings[assocId]._destinationColumnOrdinal == metadata.ordinal) ||
                         (UnquotedName(_localColumnMappings[assocId]._destinationColumnName) == metadata.column))
                     {
+                        _localColumnMappings[assocId]._matchedOrRejected = true;
+
                         if (rejectColumn)
                         {
                             nrejected++; // Count matched columns only
@@ -713,7 +715,16 @@ private string AnalyzeTargetAndCreateUpdateBulkCommand(BulkCopySimpleResultSet i
             // All columnmappings should have matched up
             if (nmatched + nrejected != _localColumnMappings.Count)
             {
-                throw (SQL.BulkLoadNonMatchingColumnMapping());
+                int assocId;
+                for (assocId = 0; assocId < _localColumnMappings.Count; assocId++)
+                {
+                    SqlBulkCopyColumnMapping columnMapping = _localColumnMappings[assocId];
+
+                    if(!columnMapping._matchedOrRejected)
+                    {
+                        throw (SQL.BulkLoadNonMatchingColumnName(columnMapping.SourceColumn));
+                    }
+                }
             }
 
             updateBulkCommandText.Append(")");

src/Microsoft.Data.SqlClient/netfx/src/Microsoft/Data/SqlClient/SqlBulkCopy.cs

@@ -607,6 +607,8 @@ private string AnalyzeTargetAndCreateUpdateBulkCommand(BulkCopySimpleResultSet i
                     if ((_localColumnMappings[assocId]._destinationColumnOrdinal == metadata.ordinal) ||
                         (UnquotedName(_localColumnMappings[assocId]._destinationColumnName) == metadata.column))
                     {
+                        _localColumnMappings[assocId]._matchedOrRejected = true;
+
                         if (rejectColumn)
                         {
                             nrejected++; // Count matched columns only
@@ -754,7 +756,16 @@ private string AnalyzeTargetAndCreateUpdateBulkCommand(BulkCopySimpleResultSet i
             // All columnmappings should have matched up
             if (nmatched + nrejected != _localColumnMappings.Count)
             {
-                throw (SQL.BulkLoadNonMatchingColumnMapping());
+                int assocId;
+                for (assocId = 0; assocId < _localColumnMappings.Count; assocId++)
+                {
+                    SqlBulkCopyColumnMapping columnMapping = _localColumnMappings[assocId];
+
+                    if(!columnMapping._matchedOrRejected)
+                    {
+                        throw (SQL.BulkLoadNonMatchingColumnName(columnMapping.SourceColumn));
+                    }
+                }
             }
 
             updateBulkCommandText.Append(")");

src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/SqlBulkCopyColumnMapping.cs

@@ -13,6 +13,7 @@ public sealed class SqlBulkCopyColumnMapping
         internal int _destinationColumnOrdinal;
         internal string _sourceColumnName;
         internal int _sourceColumnOrdinal;
+        internal bool _matchedOrRejected;
 
         // devnote: we don't want the user to detect the columnordinal after WriteToServer call.
         // _sourceColumnOrdinal(s) will be copied to _internalSourceColumnOrdinal when WriteToServer executes.

src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/SqlBulkCopyTest/MissingTargetColumn.cs

@@ -35,7 +35,9 @@ public static void Test(string srcConstr, string dstConstr, string dstTable)
                             ColumnMappings.Add("LastName", "col2"); // this column does not exist
                             ColumnMappings.Add("FirstName", "col3");
 
-                            string errorMsg = SystemDataResourceManager.Instance.SQL_BulkLoadNonMatchingColumnMapping;
+                            string errorMsg = SystemDataResourceManager.Instance.SQL_BulkLoadNonMatchingColumnName;
+                            errorMsg = string.Format(errorMsg, "LastName");
+
                             DataTestUtility.AssertThrowsWrapper<InvalidOperationException>(() => bulkcopy.WriteToServer(reader), exceptionMessage: errorMsg);
                         }
                     }