A.must contain unique values. B.cannot be CAST to other data types. C.is created using the CREATE DISTINCT command. D.contains a value that was automatically calculated from values in other columns.
单项选择题Which of the following DB2 data types has a fixed length?（）
A.XML B.BLOB C.DOUBLE D.DBCLOB
单项选择题Which of the following actions may cause a trigger to be fired?（）
A.DROP B.ALTER C.DELETE D.ROLLBACK
