如何删除表中多字段的重复项？（mysql）

Question

If a table is like this:

id | complains | zipcode
--------------------------
1  |  drinking |  10000
2  |  drinking |  10000
3  |  wasting  |  10000
4  |  wasting  |  10000
5  |  wasting  |  10000
6  |  wasting  |  10011
7  |  wasting  |  10011

I want to get just:

---------------
drinking  10000
wasting   10000
wasting   10011
---------------

How should I write a SQL query? I wrote like this, but update and select cannot be execute at same time in mySQL.

delete from table where id not in (select max(id) from table group by complains, zipcode)

Answer 1

You can use a subselect to trick MySQL:

delete from table 
where id not in 
(
     select * from (select max(id) from table group by complains, zipcode) x
)