单项选择题
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'-
A.Alt B.Delete C.Esc D.Return
A.FORB.WHILEC.WHERED.CONDITION