删除关系表中的重复行[重复]

Question

我在PostgreSQL 数据库中有一个关系表。 我想删除重复的行。

我的桌子是这样的：

idUser      idFunction
1           1
2           1
3           1
3           1
4           1
4           1
4           2

我想要这个：

idUser      idFunction
1           1
2           1
3           1
4           1
4           2

我已经试过了：

DELETE TOP (SELECT COUNT(*) -1 FROM user_function 
        WHERE idUser IN
            (SELECT idUser FROM user_function
            GROUP BY idUser, idFunction
            HAVING COUNT(*) > 1)
        AND idFunction IN
            (SELECT idFunction FROM user_function
            GROUP BY idUser, idFunction
            HAVING COUNT(*) > 1))
FROM user_function
WHERE idUser IN
    (SELECT idUser FROM user_function
    GROUP BY idUser, idFunction
    HAVING COUNT(*) > 1)
AND idFunction IN
    (SELECT idFunction FROM user_function
    GROUP BY idUser, idFunction
    HAVING COUNT(*) > 1)

但是PostgreSQL 告诉我在“TOP”处有一个error。

如何删除PostgreSQL 关系表中的重复行？

Answer 1

我可能会建议重新创建表格：

create table temp_user_function as
    select distinct idUser, idFunction
    from user_function;

truncate table user_function;   -- backup first!!!

insert into user_function (idUser, idFunction)
    select idUser, idFunction
    from temp_user_function;

您应该在修复数据后声明该对是唯一的。