我從“publisher1”查詢 50 篇文章，然后從“publisher2”查詢 50 篇文章。我結合結果回傳 100 篇文章。
我嘗試組合查詢以同時回傳結果但沒有成功。合并將提高性能，因為它們每個都需要 150 毫秒。如何將兩個查詢合并為一個，還是我必須單獨查詢？
// Query 1
SELECT * FROM news WHERE (MATCH(snippet) AGAINST('politics' IN BOOLEAN MODE)) AND (publisher = 'publisher1') ORDER BY datePublished DESC LIMIT 50
// Query 2
SELECT * FROM news WHERE (MATCH(snippet) AGAINST('politics' IN BOOLEAN MODE)) AND (publisher = 'publisher2') ORDER BY datePublished DESC LIMIT 50
我試過了 ：
SELECT * FROM news WHERE (MATCH(snippet) AGAINST('politics' IN BOOLEAN MODE)) AND (publisher = 'publisher1') ORDER BY datePublished DESC LIMIT 50 AND SELECT * FROM news WHERE (MATCH(snippet) AGAINST('politics' IN BOOLEAN MODE)) AND (publisher = 'publisher2') ORDER BY datePublished DESC LIMIT 50
uj5u.com熱心網友回復：
“如何將兩個查詢合并為一個……？ ”
使用UNION：
(SELECT * FROM news WHERE (MATCH(snippet) AGAINST('politics' IN BOOLEAN MODE)) AND (publisher = 'publisher1') ORDER BY datePublished DESC LIMIT 50)
UNION
(SELECT * FROM news WHERE (MATCH(snippet) AGAINST('politics' IN BOOLEAN MODE)) AND (publisher = 'publisher2') ORDER BY datePublished DESC LIMIT 50);
或者 ：
(SELECT * FROM news WHERE (MATCH(snippet) AGAINST('politics' IN BOOLEAN MODE)) AND (publisher = 'publisher1') LIMIT 50)
UNION
(SELECT * FROM news WHERE (MATCH(snippet) AGAINST('politics' IN BOOLEAN MODE)) AND (publisher = 'publisher2') LIMIT 50)
ORDER BY datePublished DESC;
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標籤：mysqlsql
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