1.select语句可以用回车分隔 $sql="select * from article where id=1" 和 $sql="select * from article where id=1",都可以得到正确的结果,但有时分开写或许能更明了一点,特别是当sql语句比较长时 2.批量查询数据 可以用in来实现 $sql="select * from article where id in(1,3,5)" 3.使用concat连接查询
Select * from table_name Select column_name_1,column_name_2 from table_name Select * from student where 姓名=‘刘婷’and 所在班级=2 Select * from student where 成绩 between 90 and 100 Select * from student where 姓名 like ‘刘%’ Select * from student where 备注 is NOT