单选题Which of the following can be used to ensure that once a row has been inserted in table TABLEX, the column MAINID in that row cannot be updated?()A
Define the column MAINID as NOT UPDATABLEB
Define the column MAINID as a PRIMARY KEYC
Define the column
题目
单选题
Which of the following can be used to ensure that once a row has been inserted in table TABLEX, the column MAINID in that row cannot be updated?()
A
Define the column MAINID as NOT UPDATABLE
B
Define the column MAINID as a PRIMARY KEY
C
Define the column MAINID as a FOREIGN KEY
D
Define an UPDATE trigger on table TABLEX
更多“单选题Which of the following can be used to ensure that once a row has been inserted in table TABLEX, the column MAINID in that row cannot be updated?()A
Define the column MAINID as NOT UPDATABLEB
Define the column MAINID as a PRIMARY KEYC
Define the column ”相关问题