急问一个SQL语句的问题(VB中)
在用VB编写的程序里我有一个SQL语句是这样的:
sql = "select r_id as 顺序号,shengqu as 省区,xingming as 姓名,xingbie as 性别,kscj as 考试成绩,sbrq as 申报日期,csny as 出生年月,zhiwu as 职务,zhicheng as 职称,sxzy as 所学专业,xueli as 学历,lxdh as 联系电话,gzdw as 工作单位及部门,txdz as 通信地址,youbian as 邮编,qici as 第几期 from gsp_jcydab where shengqu like '" & sq & "%' and zhicheng like '" & zc & "%' and xueli like '" & xl & " %' and xingming like '" & xm & "%' order by r_id"
上面的语句好像什么也查询不出来,如果sq,zc,xl和xm都是空的话,什么也查不出来的,请问什么原因呀?