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Start your free trialTracy Cano
6,645 PointsCan someone help me understand how to answer this question about outer joins?
Challenge Task 5 of 5 In a car database there is a Sale table with columns, SaleID, CarID, CustomerID, LocationID, SalesRepID, SaleAmount and SaleDate. The database also has a SalesRep table with columns, SalesRepID, FirstName, LastName, SSN, PhoneNumber, StreetAddress, City, State and ZipCode.
Show all SaleDate, SaleAmount, and SalesRep First and Last name from Sale and SalesRep. Make sure that all Sales appear in results even if there is no SalesRep associated to the sale.
1 Answer
Travis Alstrand
Data Analysis Techdegree Graduate 49,443 PointsHey there Tracy Cano !
For this one, we need to utilize an OUTER JOIN to make sure we're showing all Sale
s, even if there is not an associated SalesRep
for the row.
We'll want to specify what we want to select from both tables.
I decided to put the Sale
table on the "left" as it makes more sense in my head.
Then LEFT OUTER JOIN the other table where the IDs match up.
I hope this makes sense!
SELECT SaleDate, SaleAmount, FirstName, LastName
FROM Sale
LEFT OUTER JOIN SalesRep ON Sale.SalesRepID = SalesRep.SalesRepID