MYSQL的幫助，怎麼算的結果

Question

運行該SQL：

SELECT 
    user_id, 
    base_item 
FROM 
    items 
WHERE 
    base_item = "202" 

給了我這個http://prntscr.com/9gwwxq 但是，我怎麼擴大MySQL查詢加起來的202個base_items爲user_id有量。如user_id說明41 6.

Answer 1

嘗試：

SELECT 
    user_id, 
    count(base_item) as c 
FROM 
    items 
WHERE 
    base_item = "202" 
group by 
    user_id 

Answer 2

嘗試使用此方法類似base_item

SELECT 
    user_id, 
    base_item, count(*) as user_no 
FROM 
    items 
WHERE 
    base_item = "202" 
GROUP BY user_id 

Answer 3

這應該給你的每個用戶ID「202」 base_items數量count：

SELECT 
    user_id, 
    COUNT(*) 
FROM 
    items 
WHERE 
    base_item = "202" 
GROUP BY user_id