SQL SELECT Examples


The SQL SELECT statements could be complicated. The following slides give many SELECT examples, where RA means relational algebra and the CAP database is shown above.

Question I (Simple SELECT)
Find the aid values and names of agents that are based in New York.    
agent
aid aname city percent
a01 Smith New York 6
a02 Jones Newark 6
a03 Brown Tokyo 7
a04 Gray New York 6
a05 Otasi Duluth 5
a06 Smith Dallas 5
⇒
aid aname
a01 Smith
a04 Gray
Question II (SELECT All)
Display all the values in every row of the customer table.  
customer
cid cname city discnt
c001 TipTop Duluth 10.00
c002 Basics Dallas 12.00
c003 Allied Dallas 8.00
c004 ACME Duluth 8.00
c006 ACME Kyoto 0.00
⇒
cid cname city discnt
c001 TipTop Duluth 10.00
c002 Basics Dallas 12.00
c003 Allied Dallas 8.00
c004 ACME Duluth 8.00
c006 ACME Kyoto 0.00


Demonstration
Below is an SQL test area from W3Schools, which uses the well-known Northwind sample database. The tables here are for read only because of the problem of embedding the scripts. For a fully working example, check this by using Chrome.

SQL Statement:

Edit the SQL statement and click     to see the result, or  

Result:
The Database includes:
The Database includes:

TablenameRecord
Customers91
Categories8
Employees10
OrderDetails518
Orders196
Products77
Shippers3
Suppliers29




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