IFNULL 語句

SELECT IFNULL(value1,value2) AS status; 當(dāng)value1為null時(shí),返回結(jié)果為value2 當(dāng)value1非null時(shí),返回結(jié)果為value1

例1:

SELECT IFNULL('非空','空') AS status; 結(jié)果為: 非空 SELECT IFNULL(null,'空') AS status; 結(jié)果為: 空

測(cè)試結(jié)果:

mysql> SELECT IFNULL(null,'空') AS status; +--------+ | status | +--------+ | 空 | +--------+ 1 row in set

mysql> SELECT IFNULL('非空','空') AS status; +--------+ | status | +--------+ | 非空 | +--------+ 1 row in set

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