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

对GROUP BY子句执行SELECT操作。假设name是你想要在其中找到重复项的列:

SELECT name, COUNT(*) c FROM table GROUP BY name HAVING c > 1;

这将返回一个在第一列中包含名称值的结果,以及该值在第二列中出现次数的计数。

其他回答

SELECT t.*,(select count(*) from city as tt
  where tt.name=t.name) as count
  FROM `city` as t
  where (
     select count(*) from city as tt
     where tt.name=t.name
  ) > 1 order by count desc

用你的表格替换城市。 将name替换为字段名

SELECT * 
FROM `dps` 
WHERE pid IN (SELECT pid FROM `dps` GROUP BY pid HAVING COUNT(pid)>1)

试着使用这个查询:

SELECT name, COUNT(*) value_count FROM company_master GROUP BY name HAVING value_count > 1;

假设您的表名为TableABC,您想要的列是Col, T1的主键是key。

SELECT a.Key, b.Key, a.Col 
FROM TableABC a, TableABC b
WHERE a.Col = b.Col 
AND a.Key <> b.Key

与上面的答案相比,这种方法的优点是它给出了Key。

Select column_name, column_name1,column_name2, count(1) as temp from table_name group by column_name having temp > 1