A.alter table employee alter column state varchar(100) B.alter table employee column state varchar(100) C.alter table employee alter column of state varchar(100) D.alter table employee add column state varchar(100)
A.delete student where sex in(NULL) B.delete student where sex=NULL C.delete student where sex is NULL D.delete student where is NULL(sex,O)is NULL
A.更新了多行數據 B.沒有數據更新 C.更新了一行數據 D.出現錯誤