[SQL] Related table question

[Ruslan Zasukhin]

on 1/15/04 9:56 AM, Eric Forget at forgete at cafederic.com wrote:

> Hi,
> 
> I have 2 tables:
> 
>   Table1 has some fields...
> 
>   Table "Keyword" has:
> 
>       VDK_ObjectPtr        mTable1;
>       VDK_String           mName;
> 
> If I query
> 
> SELECT DISTINCT Table1.RecID FROM Table1, Keyword WHERE Keyword.Name = 'me'
> 
> I will have all the records of Table1 that have a related Keyword.Name =
> 'me'.
> 
> For the reverse I tried:
> 
> SELECT DISTINCT Table1.RecID FROM Table1, Keyword WHERE Keyword.Name <> 'me'
> 
> This will works only if the record of Table1 has at least 1 related Keyword
> relation. If it has not it is excluded. How can I include those?

You need to use LEFT OUTER JOIN

 SELECT DISTINCT Table1.RecID
 FROM Table1, Keyword
  WHERE   Table1.RecID *= Keyword.mTable1 AND
            Keyword.Name <> 'me'
    

-- 
Best regards,
Ruslan Zasukhin      [ I feel the need...the need for speed ]
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e-mail: ruslan at paradigmasoft.com
web: http://www.paradigmasoft.com

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