需要重寫sql查詢

Question

我是新來的查詢和我需要幫助編寫查詢。

我想選擇

Project_Post.ProjectPost 
from Project_Post 
Where Project_Post.ProfileId = (User_profile.ProfileID Where User_profile.UserId = @username) 
And Project_Post.Project date is less than Project_Follower.LastPageView 
Where Project_Follower.profileId = (User_profile.ProfileID Where User_profile.UserId = @username) 

謝謝。

Answer 1

應該是這樣的：

SELECT col1, col2 -- specify what you need 
FROM Project_Post pp 
INNER JOIN User_profile up ON up.ProfileId = pp.ProfileId 
INNER JOIN Project_Follower pf ON pf.profileId = up.ProfileID 
WHERE 
pp.Project_date < pf.LastPageView AND 
pp.ProfileId = (
        SELECT ProfileID 
        FROM User_profile 
        WHERE UserId = @username 
       ) AND 
pf.profileId = (
        SELECT ProfileID 
        FROM User_profile 
        WHERE UserId = @username 
       ) 

Answer 2

這將是更好，如果你給我們表的結構，而是取決於你的查詢，這是這樣的：

SELECT pp.ProjectPost 
FROM Project_Post AS pp WITH(NOLOCK) 
    INNER JOIN User_Profile AS up WITH(NOLOCK) ON pp.ProfileID = up.ProfileID 
    INNER JOIN Project_Follower AS pf WITH(NOLOCK) ON pp.ProfileID = pf.ProfileID 
WHERE up.Username = @Username 
    AND pp.Project_Date < pf.LastPageView