已知employee表中具有默认约束df_email，删除该约束的语句为（ ? ）。 A.alter talbe employee remove constraint df_email B.alter talbe employee delete constraint df_email C.remove constraint df_email from talbe employee D.alter talbe employee drop constraint df_email

已知employee表中具有默认约束df_email，删除该约束的语句为（ ? ）。 A.alter talbe employee remove constraint df_email B.alter talbe employee delete constraint df_email C.remove constraint df_email from talbe employee D.alter talbe employee drop constraint df_email

正确答案：D