无夜游魂(Souls at Night)

条件查询插入数据

2017-01-16 21:27:17

如果是正值插入0 否则是1 IF后面跟着的是条件

UPDATE some_table SET an_int_value = IF(an_int_value=1, 0, 1)

update sg_player_1 set player_lotto_times=if(player_lotto_times-1>=0,player_lotto_times-1,0) WHERE player_uid=1;
这样就能保证插入的值不会为负数

改变查询的结果
表示从第3个字符起替换4个字符 用单词 WHAT  
SELECT INSERT('Quadratic', 3, 4, 'What');
结果：'QuWhattic'
E。G。
SELECT INSERT(name, 2, 4, 'What') from aste;

select * from aste;

set player_life=if(player_life+".$hp.">=8,8,player_life+".$hp.")

select a.player_uid,if(sum(b.rank_income) >=0,sum(b.rank_income),0) as income from sg_player