SQL重复数据的提取与过滤
提取重复数据
SELECT * FROM tablename GROUP BY colname HAVING COUNT(*) > 1
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过滤重复数据
SELECT * FROM tablename GROUP BY colname HAVING COUNT(*) = 1
SQL重复数据的提取与过滤
SQL重复数据的提取与过滤
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SQL重复数据的提取与过滤