mysql - UNION mysql クエリで ORDER BY と LIMIT を使用する方法

Question

少し問題があります。次のようなMySQLクエリコードがあります。

SELECT a.id, b.name AS itemName, b.slug AS itemSlug FROM table_idx a
INNER JOIN table_product b ON b.id = a.targetid AND a.target='PRODUCT'
WHERE a.memberid=$memberid
UNION
SELECT a.id, c.name AS itemName, c.slug AS itemSlug FROM table_idx a
INNER JOIN table_news c ON c.id = a.targetid AND a.target='NEWS'
WHERE a.memberid=$memberid
UNION
SELECT a.id, d.name AS itemName, d.slug AS itemSlug FROM table_idx a
INNER JOIN table_promo d ON d.id = a.targetid AND a.target='PROMO'
WHERE a.memberid=$memberid

ORDER BY a.id DESC LIMIT 0,10上記のクエリに追加する方法は? ご協力いただきありがとうございます。

Answer 1

別の選択でラップします。

SELECT * FROM (
SELECT a.id, b.name AS itemName, b.slug AS itemSlug FROM table_idx a
INNER JOIN table_product b ON b.id = a.targetid AND a.target='PRODUCT'
WHERE a.memberid=$memberid
UNION
SELECT a.id, c.name AS itemName, c.slug AS itemSlug FROM table_idx a
INNER JOIN table_news c ON c.id = a.targetid AND a.target='NEWS'
WHERE a.memberid=$memberid
UNION
SELECT a.id, d.name AS itemName, d.slug AS itemSlug FROM table_idx a
INNER JOIN table_promo d ON d.id = a.targetid AND a.target='PROMO'
WHERE a.memberid=$memberid
) AS t ORDER BY t.id DESC LIMIT 0,10

Answer 2

あなたの意図が toORDER BYであり、LIMIT各クエリの前にある場合を除き、UNION追加するだけです

ORDER BY id DESC LIMIT 0,10

クエリの下部。