SQL count distinct

Hi,

I have a table that has fields in it like so

HA7 5PQ
HA8 6ZA
WA19 7ZE
WA20 4AZ
HA5 5AE
HA8 6RT
WA19 7ZA

and so on

I want to do a query to count all distinct postcodes excluding the last 3 digits so for the example above would look like this

HA7
HA8
WA19
WA20
HA5

Which means there are 5 distinct data

The table that it is stored in is postcode and the column is called codes

please help

Thanks,

R8VI  
R8VIAsked:
Who is Participating?
 
James MurrellConnect With a Mentor Product SpecialistCommented:
something like

select distinct left(postcode,4) from codes
0
 
mimran18Commented:
Select  Left([Field Name],3) from [Table Name] Group By Left([Field name],3)
0
 
Pratima PharandeCommented:
select distinct substring(postcode, 1, (len(postcode) - 3))  from codes
0
Free Tool: SSL Checker

Scans your site and returns information about your SSL implementation and certificate. Helpful for debugging and validating your SSL configuration.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

 
Bhavesh ShahLead AnalysistCommented:
Hi,

I think you wanted to separate data based on " " space.

if so, check out this code.

declare @str varchar(20)
set @str = 'ADDSA7 5PDAQ'


SELECT substring(@str,1,charindex(' ',@str)-1)

Open in new window


- bhavesh

0
 
deightonprogCommented:
select  count(distinct RTRIM(LEFT(RTRIM(codes ),LEN(RTRIM(codes )) - 3))) from postcode WHERE LEN(RTRIM(codes )) > 3;
0
 
mansooralia_yahooCommented:
Hi,

I think bhavesh is on right track, but need to add distinct, just like

declare @str varchar(20)
set @str = 'ADDSA7 5PDAQ'


SELECT distinct substring(@str,1,charindex(' ',@str)-1)

Open in new window

0
 
LowfatspreadCommented:
;with cte as
 ( select left(ltrim(codes)+' ',charindex(' ',ltrim(codes)+' ') -1) as OutwardPostcode
    from postcodes)
select outwardpostcode,count(*)
from cte
group by outwardpostcode
order by 1

or

;with cte as
 ( select left(ltrim(codes)+' ',charindex(' ',ltrim(codes)+' ') -1) as OutwardPostcode
    from postcodes)
select count(distinct outwardpostcode)
from cte


ps you should really store the postcode as its component parts  at least the outward and inward even if you don't go down to the sector and walk layers...  you can always have a computed column on the table or view containing the whole string




0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.