本文介紹了在 MySQL 中查找重復記錄的處理方法，對大家解決問題具有一定的參考價值，需要的朋友們下面隨著小編來一起學習吧！
問題描述
我想提取 MySQL 數據庫中的重復記錄.這可以通過以下方式完成:
I want to pull out duplicate records in a MySQL Database. This can be done with:
SELECT address, count(id) as cnt FROM list
GROUP BY address HAVING cnt > 1
結果:
100 MAIN ST 2
我想拉它以便它顯示重復的每一行.類似的東西:
I would like to pull it so that it shows each row that is a duplicate. Something like:
JIM JONES 100 MAIN ST
JOHN SMITH 100 MAIN ST
關于如何做到這一點的任何想法?我試圖避免先做第一個，然后在代碼中使用第二個查詢查找重復項.
Any thoughts on how this can be done? I'm trying to avoid doing the first one then looking up the duplicates with a second query in the code.
推薦答案
關鍵是重寫這個查詢，使其可以作為子查詢使用.
The key is to rewrite this query so that it can be used as a subquery.
SELECT firstname,
lastname,
list.address
FROM list
INNER JOIN (SELECT address
FROM list
GROUP BY address
HAVING COUNT(id) > 1) dup
ON list.address = dup.address;
這篇關于在 MySQL 中查找重復記錄的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！
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