如何从我的查询中删除 MySql 中 row_num > 2 的位置？

Question

I have this table in my database with the following schema:

nearbystops(nearbystopname, latitude, longitude, mainaddress), I have done the following query

SELECT 
    nearbystopname,
    latitude, 
    longitude, 
    mainaddress, 
    ROW_NUMBER() OVER (
        PARTITION BY 
            nearbystopname,
            mainaddress
        ORDER BY 
            nearbystopname,
            mainaddress
    ) row_num
    FROM 
    DUSAgeocodeDB.nearbystops

which gives me the following:

My question is, how would I go by deleting the results where row_num > 2 and reflecting the changes into my database?

I have tried the following code:

with cte as (
SELECT 
    nearbystopname,
    latitude, 
    longitude, 
    mainaddress, 
    ROW_NUMBER() OVER (
        PARTITION BY 
            nearbystopname,
            mainaddress
        ORDER BY 
            nearbystopname,
            mainaddress
    ) row_num
    FROM 
    DUSAgeocodeDB.nearbystops
    ) delete from cte where row_num > 1;

but it gives me the following error:

Error Code: 1146. Table 'dusageocodedb.cte' doesn't exist

Any help will be much appreciated!

Answer 1

Assuming you have a primary key on the table, then:

delete ns 
    from DUSAgeocodeDB.nearbystops ns join
         (select nearbystopname, mainaddress, min(id) as min_id
          from DUSAgeocodeDB.nearbystops ns2
          group by nearbystopname, mainaddress
         ) ns2
         on ns2.nearbystopname = ns.nearbystopname and 
            ns2.mainaddress = ns.mainaddress and
            ns.id > ns.id;

If you don't have a primary key, your best bet might be to repopulate the table:

create table temp_ns as 
    select nearbystopname, latitude, longitude, mainaddress, 
           row_number() over (partition by nearbystopname, mainaddress) as seqnum
    from DUSAgeocodeDB.nearbystops ns;

truncate table DUSAgeocodeDB.nearbystops ns;  -- SAVE first!!!

insert into DUSAgeocodeDB.nearbystops (nearbystopname, latitude, longitude, mainaddress)
    select nearbystopname, latitude, longitude, mainaddress
    from temp_ns
    where seqnum = 1;