Question

I have a table like

City    POSTAGE   PRICE**                   

HOUSTON   DEFAULT    20
DEFAULT   AIR        14
DEFAULT   GROUND     30
DEFAULT   DEFAULT    40

Now i want to query for price on this table with a combination like ‘CHICAGO,GROUND’
which should check if the perfect combination exists, else i should substitute DEFAULT and search for the value..

example,
HOUSTON,AIR should return 14
HOUSTON,GROUND should return 20
HOUSTON,FEDEX should return 20
CHICAGO,FEDEX should return 40

Is there a way to achieve this instead of writing multiple queries ..

thank you!

Answer 1

This uses the SQL*Plus syntax for passing parameters, you may need to change that to suit:

 select price
 from your_table
 where ( city = '&p_city' or city = 'DEFAULT') 
 and ( postage = '&p_postage' or postage = 'DEFAULT') 
 order by case when city = '&p_city' then 1 else 2 end 
          , case when postage = '&p_postage'  then 1 else 2 end 

This will return multiple rows but presumably you want only the one PRICE. The ORDER BY clause prioritises matches on CITY over matches on POSTAGE. You can then select the first row.