高级MySQL IF功能

Question

我正在尝试在MySQL中执行IF功能，我认为它非常简单，但似乎有点复杂。

以下是这个想法：

SELECT IF(score1>score2, (name1,score1,name2,score2),(name2,score2,name1,score1)) AS (winner,w_score,loser,l_score) FROM game table

我要做的是测试得分1＆gt;得分2，取决于结果，订购我想要的字段。

Answer 1

考虑score1，score2，name1，name2是game表格中的列名称，您可以这样做：

SELECT
     IF( score1 > score2 ,name1 ,name2 ) AS winner
    ,GREATEST( score1 ,score2 ) AS w_score
    ,IF( score1 > score2 ,name2 ,name1 ) AS loser
    ,LEAST( score1 ,score2 ) AS l_score
FROM
    game

Answer 2

我提供了一个简单的解决方案：

SELECT name1 AS winner, score1 AS w_score, name2 AS looser, score2 AS l_score
FROM game table WHERE score1 > score2
UNION
SELECT name2 AS winner, score2 AS w_score, name1 AS looser, score1 AS l_score
FROM game table WHERE score2 > score1

Answer 3

看起来你需要的是四种不同的IF语句：

SELECT 
    IF(score1 > score2, name1, name2) AS winner,
    IF(score1 > score2, score1, score2) AS w_score,
    IF(score1 > score2, name2, name1) AS loser,
    IF(score1 > score2, score2, score1) AS l_score
FROM game_table

这不是最漂亮的事情，但由于比较非常简单，它应该表现得很好。