【leetcode】※627. Swap Salary

em不熟，

case when then else

# Write your MySQL query statement below
update salary 
set
    sex = case sex
    when "m" then "f"
    else "m"
end

331ms  62.55%

----------------------------------------------

amazing  以为是一样的结果不一样。

那记住case when连着放

# Write your MySQL query statement below
update salary 
set
    sex = case when
    sex = 'm' then 'f'
    else 'm'
end

303ms  84.06%

---------------------------------------

301ms   85.56%

惊了，就是换了一下格式就发现又前进了一些。

那记住，把所有的关键词都放在左边，case when放一起。

# Write your MySQL query statement below
update salary 
set sex = 
case when sex = 'm'
then 'f'
else 'm'
end

--------------------------

71.77%  很特立独行的一种方法，创新

# Write your MySQL query statement below
update salary 
set sex = char(ASCII('f')+ASCII('m')-ASCII(sex))

------------------------------

47.99%

# Write your MySQL query statement below
update salary 
set sex = char(ASCII('f')^ASCII('m')^ASCII(sex))

-----------------------------------

就是没想到if-else可以这样写   60.50%

# Write your MySQL query statement below
update salary 
set sex = if(sex='m','f','m')