Is it possible to Select distinct value from different columns?

[abdfahim]

As I say, Is it possible to Select distinct value from different columns in a single statement? Like

 

Select Distinct Column1, Column2, Column3 From Table

 

(Well, I dont know whether there is a syntax like this !!!)

[Illusion]

DISTINCT on three columns results all the records that have distinct combination of these there columns not the distinct values from the each column.

[pnj]

Something like this is closer:

select distinct(col1) as a from table1 union select distinct(col2) as a from table2;

 

But you could get a duplicate if the same data is in different columns.  If this is the case, you could try a subquery:

 

select distinct(a) from (select distinct(col1) as a from table1 union select distinct(col2) as a from table2) as foo

 

cheers

-pnj