[thelist] Weird SELECT DISTINCT error

Luther, Ron Ron.Luther at hp.com
Fri Dec 16 07:43:57 CST 2005


Matt Warden noted:

>>... it is difficult to see how DISTINCT could operate on only one
column.


Hi Matt,


?Que?  

DISTINCT, (as I understand it anyway), operates across all of the fields

in your select statement.

Soooooo ... running a simple 'select distinct' on a single column turns 
out to be a nice neat trick to get a quick list of all of the unique 
values in that column.

Want to know all of the countries you have shipped product to so far
this 
month?   A simple 'Select Distinct Ship_To_Country From Some_Ship_Table 
Where Ship_Date >= 1-Dec-2005', (formatted for your db du jour), should 
get you that list of countries.

Very handy stuff.  [With a smallish db I've seen folks use 'select 
distinct's to populate their drop-down controls.]


HTH,

RonL.




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