的MySQL從表中選擇其中條件x和子查詢

Question

我想表A登記的數量都在表B.確定的時間具體數額

我要找的正確的方式做一些像此：

SELECT count(*) as total 
from table_a as a 
WHERE a.created >= '0000-00-00 00:00:00' 
AND a.created <= (SELECT table_b.end WHERE table_b.id = 13) 

基本上，表-B由3米欄：命名的「id」的int主鍵，一個名爲「開始」的日期時間，並命名爲「結束」的其他日期時間。這是我確定今年所有周的方式。

Answer 1

以防萬一有人需要的是，這是做的正確方法即：

SELECT count(*) as total 
from table_a as a 
WHERE a.created >= '0000-00-00 00:00:00' 
AND a.created <= (SELECT table_b.`end` FROM table_b WHERE table_b.`id`=13) 

Answer 2

SELECT count(*) as total 
from table_a as a 
WHERE a.created >= '0000-00-00 00:00:00' 
AND a.created <= (SELECT table_b.end from table_b WHERE table_b.id = 13) 

Answer 3

你可以做典型的聯接：

SELECT COUNT(*) AS total 
FROM table_a AS a 
JOIN table_b as b ON (a.created >= '0000-00-00 00:00:00' and a.created <= b.`end`) 
WHERE b.id=13; 

鑑於你可能想要做的說明：

SELECT COUNT(*) AS total 
FROM table_a AS a 
JOIN table_b as b ON (a.created >= `start` and a.created <= `end`) 
WHERE b.id=13; 

Answer 4

你可以使用BETWEEN子句來實現這一點，

SELECT count(*) as total 
from table_a a 
WHERE a.created BETWEEN '0000-00-00 00:00:00' 
AND (SELECT table_b.`end` FROM table_b WHERE table_b.`id`=13)