第四课 过滤数据

4.1 使用where字句

select * from products where prod_price > 5

 

筛选出prod_price > 5的数据，注意where字句在order by之前，所有的操作都在旁边那幅图里面，有几个需要记住的！=，between，is null

 

4.2 where 字句操作符

 记住几个关键的操作符使用

select * from products where prod_price > 5;
select * from products where prod_price IS NOT NULL;
select * from products where prod_price IS NULL;
select * from products where prod_desc BETWEEN 3 and 10