Working with multiple tables 25

For real data, we would need to go through these records and find out why, fixing those that

can be fixed. Once we do fix it, we could get rid of the  album  column in the newSongs

table.

One other thing to fix in newSongs is the ID column: it was not transferred over as auto

increment. So go ahead and switch the ID column to auto increment.

First, it tells you  invalid default value for ID . Switch  Null  to YES and the default value

to NULL. Then, you'll get a different error.

Try the following:

select * from newSongs where id=7185

This is the Time Warp from the Rocky Horror Picture Show. It's in there twice. How many

items do we have like this?

select id, artist, song, album, count(*) as idCount from newSongs group by id

having idCount > 1

Having is a form of where  that  often  works  better  after  group  by.  If  you  can  use  where,

however, it is almost always a better choice.

Looks like we have 61 songs that ended up getting duplicated. Why?