如何判断MySQL 返回的查询结果为空

判断MySQL 返回的查询结果为空：

$link=mysql_connect(*********)

$sql="SELECT count FROM `test` WHERE value = 10000"

$result=mysql_query($sql,$link)

if($result){

echo "成功"

}else{

echo "失败"

}

1、创建测试表，

create table test_person(id int, RMB int)

2、插入测试数据

insert into test_person values(1,180)

insert into test_person values(2,170)

insert into test_person values(3,290)

insert into test_person values(4,160)

insert into test_person values(5,299)

insert into test_person values(6,266)

insert into test_person values(7,155)

3、查询表中所有记录，select t.* from test_person t，

4、编写sql，汇总每个vip类型的用户数，

select vip_type, count(distinct id)

from (select case when RMB>100 and RMB<200 then 'VIP1' when RMB>200 then 'VIP2' end as vip_type, id

        from test_person) t

group by vip_type

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