• 2022-10-26
    如果要为student 表增加一列,列名叫“telephone”,数据类型为可变长度字符串类型,那么利用SQL所写的语句是( )
    A: alter table student add telephone varchar(10)
    B: insert student into values (telephone char(10))
    C: add table student alter column telephone varchar(10)
    D: insert student telephone char(10 )
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