A. create B. delete C. update D. insertinto
A. 主键约束 B. 外键约束 C. 默认值约束 D. 非空约束
A. deletefrom学生where年龄in(19,21) B. deletefrom学生where年龄between19and21 C. deletefrom学生where年龄=19or年龄=21 D. deletefrom学生where年龄=19and年龄=21
A. altertable学生addcolumn班级 B. altertable学生addcolumn班级char(10)notnull C. altertable学生add班级char(10)notnull D. altertable学生addcolumn班级char(10),notnull
A. select B. insertinto C. update D. delete
A. addinto B. append C. insert D. insertinto