每个字段都能应上，大小也写完全一样
但是还是报如题那个错，
```
DataTable excelData = GetDataTableFromExcelFile(targetFile, TgtDbConn, TgtDbTable1);
using (SqlConnection dbConnection = new SqlConnection(TgtDbConn))
{
dbConnection.Open();
if (dbConnection.State == ConnectionState.Open)
{
using (SqlBulkCopy s = new SqlBulkCopy(dbConnection))
{
s.DestinationTableName = TgtDbTable;
for (int i=0;i< excelData.Columns.Count;i++)
{
s.ColumnMappings.Add(excelData.Columns[i].ColumnName, excelData.Columns[i].ColumnName);
}
s.WriteToServer(excelData);
}
}
dbConnection.Close();
```求解答