查询变量

   日期:2017-06-15

 字符串型变量要加单引号 “select * from biao where 学生=’”+ mystr +”’”
 查数值型变量”select * from biao where 成绩>” + myfen
 查询日期型变量”Select * from biao where 出生日期=’” + mydate +”’”(Sql server)
 查询日期型变量”Select * from biao where 出生日期=#” + mydate +”#”(Access)