I have the following sql command through code and because the parameter contains a forward slash when I evaluate the sql row after the update the column is just empty.

sqlCommand.CommandText = String.Format("update {0} set {1}='{2}'where id = @Id",
                                        tableName, ColumnName, forwardSlashText);
sqlCommand.Parameters.Add("@Id", SqlDbType.UniqueIdentifier).Value = rowId;
numRowsAffected = sqlCommand.ExecuteNonQuery();

adding a log.debug to this command i get the following output...

update my_table_name set mime_type='application/pdf' where id = @Id

So i would assume that the command is correct, but then looking at the row the mime_type column is empty.