•Write 5 Queries and explain what they would return. Use the database on the pre

Question

•Write 5 Queries and explain what they would return. Use the database on the previous slides. At least two of the queries must contain some form of join.

O Songs Artists O Group_Membership V Song_Id INT Artist _Id INT P Group_Id INT Song_Name VARCHAR(300) O Artist_F_Name VARGHAR(45) Artist Id INT O Song Language V ARCHAR(45) O Artist L_Name VARCHAR(45) Music_Groups O Track _Number INT Group_ID INT I Indexes Group_Name VARCHAR(45) D Albums O Date _Formed DATE Album _Id INT O Studio INT to Album _Name VARCHAR(45) ––– Indexes Creator INT Indexes O Studios Studio_ID INT Name VARGHAR(45) IT Indexes

Explanation / Answer

select * from Songs cross JOIN Song_List;

The result is Cartesian product of rows in tables.

2. select * from Songs,Song_List where Songs.Song_Id=Song_List.Song_Id;

This query results in records which are matched on equality.

3.select * from Song_List NATURAL JOIN Albums

It returns the record with matched Album_Id from the tables.

4.select * from Artists full outer join Group_Membership on (Artists.Artist_Id=Group_Membership. Artist_Id );

It returns all matched records from both the tables and then unmatched record s from both tables with null values.

5.select *from Group_Membership Left outer join Music_Groups( Group_membership.GroupId=Music_Groups. Group_Id);

It returns all matched records from both tables and all left table records with null values for table2.fields.

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