寫一下語句，加深記憶
select case column_name1?
????when value1 then result1?
????[when value2 then result2.....][else result]?
????end [as column_new_name]
????[,case?
?????when expr1 then result1?
????[when expr2 then result2...]
????[else result]?
????end [as column_new_name]
? ? [,case...]
????]
from tb_name;
2018-12-05
select case column_name1
when value1 then result1
[when value2 then result2.... ][else result]
end [as column_new_name]
[,case?
when expr1 then result1
[when expr2 then result2...]
[else result]
end [as column_new_name]
[,case...]
]
from tb_name;