使用ANSI CASE语句/表达式:
SELECT CASE
WHEN LENGTH(col) = 0 OR col IS NULL THEN 'banana'
ELSE col
END AS fruit
sql或MysqL中没有布尔值。MysqL实际上将该值存储为INT,值为零或一:
SELECT CASE
WHEN col = 0 THEN 'banana'
ELSE col
END AS fruit