MySQL elt()函数

SELECT        elt(        INTERVAL ( c.load_percent,    0, 25, 50, 75, 100,2000),        '0~25%', '25%~50%',    '50%~75%', '75%~100%',    '>100%'        ) AS deviceId,        count(c.id) AS loadPercent,        data_date dataDate        FROM        table c        GROUP BY        data_date,        elt(        INTERVAL ( c.load_percent,    0, 25, 50, 75, 100,2000),        '0~25%', '25%~50%',    '50%~75%', '75%~100%',    '>100%'        )limit #{offset},#{limit}

偷了懒，没有实现行专列的功能（ps：本来我的SQL水平就不怎么好，写的时候要么看教程，要么百度T，T）