单项选择题
A.ALTER TABLE B.MODIFY TABLE C.ALTER STRUCTURE D.MODIFY STRUCTURE
A.INSERT B.UPDATE C.DELETE D.CHANGE
A.SELECT*FROM订单WHERE HEAD(订购单号,1)=”到 B.SELECT*FROM订单WHERE LEFT(订购单号,1)=nPn C.SELECT*FROM订单WHERE””$订购单号 D.SELECT*FROM订单WHERE RIGHT(订购单号,1)_"P'-