Re: Something strang on "left join"

On 09/28/2017 08:17 AM, 陳世泓 wrote:
> Hi,
>
>  
>
>         My pgsql version is 9.6, and I got something wrong result while
> using left join.
>
>        
>
>         We used “left join” to join t1 and t2, the result of the first
> row was wrong ,here is the LEFT JOIN result.  
>
>  
>
> 1.     select * from cicifcif
>
> 2.     select * from eccifidi
>
> 3.     select * from cicifcif t1 left join eccifidi t2 on
> t1."CI-CUST-NO" = t2."EC-CUST-NO" ORDER BY T1."CI-CUST-NO"
>
>  
>
>   THE LEFT JOIN RESULT OF THE FIRST ROW , COLUMNS OF eccifidi SHOULD BE
> “222”,”N”,”Y”….
>

Chances are some of the ID columns contain spaces or some other
whitespace characters. Try length() on them:

SELECT length("CI-CUST-NO") FROM ...
SELECT length("EC-CUST-NO") FROM ...

regards

--
Tomas Vondra http://www.2ndQuadrant.com
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