select * from orderitems where orderitems123.sku!=orderitems.sku

What is the question?

i want to know the rows in orderitems table
where orderitems123.sku!=orderitems.sku

All records in orderitems where the sku does not exist in the other table orderitems123

select a.*
from orderitems a
left join orderitems123 b on a.sku=b.sku
where b.sku is null

select orderitems.*
from orderitems
inner join orderitems123 on orderitems123.itemid = orderitems.itemid and  orderitems123.sku <> orderitems.sku

Please try this:

select * from orderitems
      Inner Join orderitems123 On orderitems123.itemid=orderitems.itemid
            And orderitems123.sku!=orderitems.sku

Or if they both have itemid, and you want to match by itemid but where the sku for the itemid-itemid match is not the same:

select a.*
from orderitems a
join orderitems123 b on a.itemid=b.itemid
where a.sku!=b.sku

orderitems is newer than orderitems123 so orderitems will have more rows which means itemid (primary key)

You can swap sku for itemid in the query I gave earlier

i.e. new rows in orderitems

select a.*
from orderitems a
left join orderitems123 b on a.itemid=b.itemid
where b.itemid is null

how to combine

select a.*
from orderitems a
join orderitems123 b on a.itemid=b.itemid
where a.sku!=b.sku


select a.*
from orderitems a
left join orderitems123 b on a.itemid=b.itemid
where b.itemid is null


want rows where sku are different (different skus, or one row doesnt exist)

If orderitems has skus as 1,2,3,4 and orderitems123 has skus as 3.4,5,6. Now based on this sample, which skus are you expecting in the result set?

type in previous post. Its supposed to be comma between 3 and 4.

If orderitems has skus as 1,2,3,4 and orderitems123 has skus as 3,4,5,6. Now based on this sample, which skus are you expecting in the result set?

thanks