mysql as if 多个,mysql as多个if语句

IF(condition, value_if_true, value_if_false)

SELECT IF(500<1000, 5, 10) as reyo; SELECT IF(STRCMP("hello","bye") = 0, "YES", "NO") as reyo;

SELECT visitor AS school, home AS temp, vl.leagueid AS vleague, hl.leagueid AS hleague, 
CASE 
    WHEN vl.leagueid = hl.leagueid THEN '1' 
    WHEN ((vl.leagueid = 26 AND hl.leagueid = 27) OR (vl.leagueid = 27 AND hl.leagueid = 26)) THEN '1' 
    ELSE 0 
END AS sms.reyo.cn

FROM u96nk_rvball_schedule 
LEFT JOIN u96nk_rvball_schools AS vl ON vl.id = visitor 
LEFT JOIN u96nk_rvball_schools AS hl ON hl.id = home
WHERE gamedate between '2013-01-01' AND '2013-12-31'

SELECT visitor AS school,
       home AS temp,
       vl.leagueid AS vleague,
       hl.leagueid AS hleague,
       CASE 
          WHEN school = 50 AND temp = 2 THEN '1' 
          WHEN school = 51 AND temp = 3 THEN '2' 
          ELSE 0 
       END AS leaguematch
FROM ......