The columnNames attribute represents the names of the columns in the rows.

The errorBlock attribute represents the block of code that is run when an error occurs in the data access code.

The lastError attribute is the last error that occurred. You can tear off the lastError attribute to access the error information.

For more information on the self attribute, refer to Using the self attribute.

The names of the actual columns in the table as a result of the query if it was successfully applied.

The valueHolder attribute holds the value of the variable or class.