Please start any new threads on our new
site at https://forums.sqlteam.com. We've got lots of great SQL Server
experts to answer whatever question you can come up with.
| Author |
Topic |
|
hero
Starting Member
1 Post |
 Posted - 2010-04-30 : 16:16:58
|
Hello everybody, hello Dani!I'm doing my homework of 'Data Base', exactly in the chapter: Relational Algebra, here I am, I can't find a specific relation (or the SQL corresponding query) !Here the schema:MEAL(guest,date);MENU(dish,date);PREFERENCE(person,dish);I wanna find the SQL query (or the relation in Relational Algebra):"the guests who attended to every dish".I'm semi-sure that we must use the division operation, but how?This my try in relational algebra(I'd like to know the SQL corresponding query):R1:JOIN(MEAL,MENU);R2:PROJECT(R1,guest,dish);R3:PROJECT(R1,dish);R4:DIVISION(R2,R3); Or how .. I need help  I hope find a solution or a lil hint!Greeting! |
|
|
visakh16
Very Important crosS Applying yaK Herder
52326 Posts |
Posted - 2010-05-01 : 00:29:05
|
| group on the person and take the distinct count of dish. this should be equal to distinct count of dish in dish table.------------------------------------------------------------------------------------------------------SQL Server MVPhttp://visakhm.blogspot.com/ |
 |
|
|
|
|
|
SQL query .. please!