MySQL組通過查詢X或不是X

Question

這應該很容易，但我還沒有找到答案。我有一個正在運行一個計數的查詢，並且我想在查詢中將其分組到State = 1和State <> 1並且爲每個組計算總和。

SELECT count(`id_job`) as count, `state` 
FROM job_table 
GROUP BY `state`; 

Answer 1

您可以通過它也查詢布爾表達式和組：

SELECT state = 1, COUNT(*) 
FROM  job_table 
GROUP BY state = 1 

Answer 2

試試這個

SELECT SUM(CASE WHEN State=1 THEN 1 END) as count1, 
     SUM(CASE WHEN State<>1 THEN 1 END) as count2, 
     State 
FROM job_table 
GROUP BY state 

Answer 3

SELECT count(id_job) as count,state FROM job_table 
    GROUP BY case when state = 1 then 1 else 0 

Answer 4

在MySQL中，你可以很容易地把這些成列：

select sum(state = 1) as state_1, 
     sum(state <> 1) as state_2 
from job_table; 

如果state可以是NULL，那麼您想要小心一點。第二個條件更安全，因爲：

select sum(state = 1) as state_1, 
     sum(not state <=> 1) as state_2 
from job_table;