<java-digest elide>
On 04-Jul-01 Asha Ramaiah wrote:
> Hey! guys!
>
> I wanted a little help on the following : ..
>
> Scenario:
> I have 2 tables : one task and the other tasksequence
>
> desc task : (primary key taskId, varchar taskdesc)
> desc tasksequence (primary key (taskId,milestoneId))
>
> Now the query I want to form should give me a list of all taskIds in table
> task
> excluding the taskIds frm tasksequence..( a result set of >15 rows(taskIds))
>
> Can somebody help me with this ??...I have developed a quick fix for this :
>
> -- capture the resultset of all the taskIds in tasksequence , as a string
>
> --and then : "select taskId from task where taskId not in (taskIdsString)"
>
> Its working , but is the same not possible with left/right or natural
Start reading the manual, pay attention at:
"If there is no matching record for the right table in the ON or USING part in
a LEFT JOIN, a row with all columns set to NULL is used for the right table.
You can
use this fact to find records in a table that have no counterpart in
another table:
mysql> select table1.* from table1
LEFT JOIN table2 ON table1.id=table2.id
where table2.id is NULL;
"
stop reading.
--
Don Read [EMAIL PROTECTED]
-- It's always darkest before the dawn. So if you are going to
steal the neighbor's newspaper, that's the time to do it.
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