Need Helps with SQL Queries for School Assignment

If anyone can take a look at this and tell me what I am doing wrong, I would surely appreciate it. I am using my textbook and W3schools SQL Tutorials and can't figure out why I keep having issues with these two specific queries...

Question: 335
Write an SQL statement to display the OwnerLastName, OwnerFirstName, and OwnerEmail of any owners of cats. Use a subquery with PET_OWNER and PET_3.

PET_OWNER

PET_3

QUERY:
SELECT OwnerLastName, OwnerFirstName, OwnerEmail
FROM PET_OWNER
WHERE PET_OWNER.OwnerID= (SELECT PET_3.OwnerID FROM PET_3
WHERE Pet_3.Pettype='Cat')
-----
It Returns: Query failed: Subquery returns more than 1 row

Screenshot:





https://gyazo.com/42b58823f433cf1671aef535b3e8e7cf

and the next question is the same as the above but I also have to include the Cat name 'Teddy'..

Screenshot:
https://gyazo.com/a6a13976a6481c0b2fc4256ad5941af2

I appreciate any help I can get here because I am at a lost. I did think about using a 'View' or a 'Join', but not even sure if those would work. I just cannot understand why what I did try will not work. Seems pretty straight forward, but still returns errors no matter what I try. The thing that is most frustrating is that I WANT it to return more than one row..

Your subquery returns more than 1 record and you have an equal sign. Use IN instead.

SELECT OwnerLastName, OwnerFirstName, OwnerEmail
FROM PET_OWNER
WHERE PET_OWNER.OwnerID IN (SELECT PET_3.OwnerID FROM PET_3
WHERE Pet_3.Pettype='Cat')

Thanks a lot for the help. I was able to just add the AND statement for the cats name for the second query and it worked like a charm too.

ok,

I have 3 tables table 1 and table 2 share keys
Table 2 and table 3 share keys
I need to query 3 columns from table one that correalate with 1 column from table 3 that meets certain guidelines.

How do I make the connection between Table 1 and 3 (obviously through table 2) and display the information in a single query?

I think by keys you mean primary-foreign key relationships? I'm assuming these three tables are normalized and you have the primary keys from table 1 and 3 in table 2? I'm thinking that's the goal here but not sure.

It would be something like

select * from table1 t1
join table2 t2 on t1.id = t2.id
join table3 t3 on t2.id = t3.id
where .......

This just doesn't make any sense. Everything I can find, including the last reply says that this should return the data. The column heading I queried coome up, but the data is empty... anyone see what I am doing wrong or is this an issue with the SQL app they have us using?



Question: 341
Write an SQL statement to display the OwnerLastName, OwnerFirstName, PetName, PetType, PetBreed, and AverageLifeExpectancy for pets with a known PetBreed. Use PET_3. The PET_OWNER, PET_3, and BREED tables are below.

SELECT OwnerLastName, OwnerFirstName, OwnerEmail from PET_OWNER join PET_3 on PET_OWNER.OwnerID = PET_3.OwnerID join BREED on PET_3.PetType = BREED.BreedName where AverageLifeExpectancy> 15;

You're joining on the wrong column

Change this PET_3.PetType = BREED.BreedName

to

PET_3.PetBreed = BREED.BreedName