How to use SqlBulkCopyColumnMappingCollection?

Question

I want to make one SqlBulkCopy method that I can use for all my bulk inserts by passing in specific data through the parameters.

Now I need to do mapping on some of them. I don't know how to make a SqlBulkCopyColumnMappingCollection since that was my plan to pass in the mapping collection in and use it. However I don't know how to make it. I can't make a new object of it.

This is what I have now. How can I add it do mapping put pass it in?

public void BatchBulkCopy(DataTable dataTable, string DestinationTbl, int batchSize)
{
 // Get the DataTable 
 DataTable dtInsertRows = dataTable;
 using (SqlBulkCopy sbc = new SqlBulkCopy(connectionString, SqlBulkCopyOptions.KeepIdentity))
 {
 sbc.DestinationTableName = DestinationTbl;
 // Number of records to be processed in one go
 sbc.BatchSize = batchSize;
 // Finally write to server
 sbc.WriteToServer(dtInsertRows);
 }
}

• iTSrAVIE: you cannot add SqlBulkCopyColumnMappingCollection to bulkCopy.ColumnMappings as later is get only. you can use Add method of bulkCopy.ColumnMappings to add mappings one at a time.

Answer 1

You don't need to create a new instance of it - the SqlBulkCopy class has a property which is a mapping collection that you can use:

public void BatchBulkCopy(DataTable dataTable, string DestinationTbl, int batchSize)
{
 // Get the DataTable 
 DataTable dtInsertRows = dataTable;
 using (SqlBulkCopy sbc = new SqlBulkCopy(connectionString, SqlBulkCopyOptions.KeepIdentity))
 {
 sbc.DestinationTableName = DestinationTbl;
 // Number of records to be processed in one go
 sbc.BatchSize = batchSize;
 // Add your column mappings here
 sbc.ColumnMappings.Add("field1","field3");
 sbc.ColumnMappings.Add("foo","bar");
 // Finally write to server
 sbc.WriteToServer(dtInsertRows);
 } 
}

EDIT:

Based on the comments, the goal was to make a generic function, e.g. not have to hardcode the mapping explicitly in the function. Since the ColumnMappingCollection cannot be instantiated, I would recommend passing a List<string> or similar that contains the column mapping definition into the function. For example:

var columnMapping = new List<string>();
columnMapping.Add("field1,field3");
columnMapping.Add("foo,bar");

Then re-define the function as

public void BatchBulkCopy(DataTable dataTable, string DestinationTbl, int batchSize, List<string> columnMapping)
{
 // Get the DataTable 
 DataTable dtInsertRows = dataTable;
 using (SqlBulkCopy sbc = new SqlBulkCopy(connectionString, SqlBulkCopyOptions.KeepIdentity))
 {
 sbc.DestinationTableName = DestinationTbl;
 // Number of records to be processed in one go
 sbc.BatchSize = batchSize;
 // Add your column mappings here
 foreach(var mapping in columnMapping)
 {
 var split = mapping.Split(new[] { ',' });
 sbc.ColumnMappings.Add(split.First(), split.Last());
 }
 // Finally write to server
 sbc.WriteToServer(dtInsertRows);
 }
}

• chobo2: I am aware of that however. Now you just tied this method to a single table(Unless I have every single table with the same column names). I am trying to make a generic method here that I can pass in any table and do a sqlbulkcopy. So if I need 5 different sqlbulkcopy inserts I don't have 5 of these methods with almost the same code except for the mapping.
• goric: Given that the function should be generic, and you can't instantiate the ColumnMappingCollection, I'd recommend passing in a representation of the mapping - see the edit above.
• chobo2: Ya that's the way I figured out too expect I just send in a List of ColumnMappings instead of strings.