我有一个varchar列的表，我想找到在这个列中有重复值的所有记录。我可以使用什么查询来查找重复项?
当前回答
为了获得所有包含复制的数据，我使用了以下方法:
SELECT * FROM TableName INNER JOIN(
SELECT DupliactedData FROM TableName GROUP BY DupliactedData HAVING COUNT(DupliactedData) > 1 order by DupliactedData)
temp ON TableName.DupliactedData = temp.DupliactedData;
TableName =您正在使用的表。
DupliactedData =您正在寻找的重复数据。
其他回答
SELECT ColumnA, COUNT( * )
FROM Table
GROUP BY ColumnA
HAVING COUNT( * ) > 1
试着使用这个查询:
SELECT name, COUNT(*) value_count FROM company_master GROUP BY name HAVING value_count > 1;
如果要删除具有多个字段的重复行，首先将它们取消为唯一不同的行指定的新唯一键，然后使用group by命令删除具有相同新唯一键的重复行:
Create TEMPORARY table tmp select concat(f1,f2) as cfs,t1.* from mytable as t1;
Create index x_tmp_cfs on tmp(cfs);
Create table unduptable select f1,f2,... from tmp group by cfs;
Select column_name, column_name1,column_name2, count(1) as temp from table_name group by column_name having temp > 1
为了获得所有包含复制的数据，我使用了以下方法:
SELECT * FROM TableName INNER JOIN(
SELECT DupliactedData FROM TableName GROUP BY DupliactedData HAVING COUNT(DupliactedData) > 1 order by DupliactedData)
temp ON TableName.DupliactedData = temp.DupliactedData;
TableName =您正在使用的表。
DupliactedData =您正在寻找的重复数据。
