Mysql基础第九天,过滤数据

Posted 2021-07-02 2019ab

1.使用WHERE子句

2.WHERE子句的操作符

	select prod_name,prod_price from products where prod_price = 2.5;  // 检查单个值
	select cust_name,cust_city from customer where cust_city = 'Chicago'; // 检查单个值
	select prod_name,prod_price from products where prod_price != 2.5; // 不匹配检查
	select prod_name,prod_price from products where prod_price >= 1; // 范围查询
	select prod_name,prod_price from products where prod_price is null;  // 空值检查
	select prod_name,prod_price from products where prod_price is not null;  // 空值检查
	
	

3.小结