SELECT * FROM
cdb_library a ,
(SELECT COUNT(1) AS SUM, CONCAT(title,publish) AS longStr FROM cdb_library GROUP BY title, publish) b
WHERE CONCAT(a.title,a.publish) = b.longStr AND b.sum>1 AND a.shenhe=1 ORDER BY title, publish
本文深入探讨了使用SQL进行复杂数据库查询的技术,特别是通过联表和子查询实现数据聚合的方法。通过对具体案例的分析,展示了如何高效地从多个数据表中提取并处理重复数据,为读者提供了实用的SQL技巧。
SELECT * FROM
cdb_library a ,
(SELECT COUNT(1) AS SUM, CONCAT(title,publish) AS longStr FROM cdb_library GROUP BY title, publish) b
WHERE CONCAT(a.title,a.publish) = b.longStr AND b.sum>1 AND a.shenhe=1 ORDER BY title, publish

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