例1:
CASE
WHEN aer.followupdate='null'
THEN null
ELSE aer.followupdate
END followupdate,
例2:
CASE
WHEN instr(O.branchno,'xiaomi')>0
THEN '小米'
WHEN instr(O.branchno,'huawei')>0
THEN '华为'
WHEN instr(O.branchno,'iphone')>0
THEN '苹果'
ELSE O.branchno
END brand,