---create table category_keyword_bak as select * from category_keyword;
delete from category_keyword where rowid not in (select min(rowid) from category_keyword group by keyword_id,category_id)
delete from category_keyword where rowid not in (select min(rowid) from category_keyword group by keyword_id,category_id)
本文介绍了一种数据库优化的方法,通过创建备份表并删除重复记录来提高查询效率。具体步骤包括:1. 创建备份表;2. 删除原表中多余的重复记录。
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