Training Course
tc_seq_no (primary key)
tc_trm_seq (foreign key to train_mod table)
... and some other title, desc etc fields
train_mod
trm_seq_no (primary key)
trm_trc_seq (foreign key to train_comp table)
.. and title etc fields
train_comp
trc_seq_no (primary key)
.. and title etc fields
We don't qualify the field names in the where because there is really
no chance we have duplicate field names. This is because of the
software we use to access Postgres. Thats also the reason for the all
caps. all of the query up to the where is put together for me based
on info I set up for the query.
Hope this info helps. I'm sure there is something wrong with the join
or something, I just don't see it.
Christine
At 10:22 AM 16/09/2010, you wrote:
>On 16/09/2010 16:05, Christine Penner wrote:
>>I have a query that joins 3 tables, TRAIN_MOD,TRAIN_COMP and
>>TRAINING_COURSE,
>>
>>There could be many training_course records for each of the other
>>tables. I want to get all records from the Train_mod and Train_comp
>>table even if there are no training course records available. This is
>>the query I'm trying and I get nothing. The data I'm trying this on has
>>no training_course records but does have records in the other tables.
>>What am I doing wrong.
>>
>>
>>SELECT *
>>FROM TRAIN_MOD LEFT OUTER JOIN TRAINING_COURSE ON
>>TRAIN_MOD.TRM_SEQ_NO=TRAINING_COURSE.TC_TRM_SEQ
>>LEFT OUTER JOIN TRAIN_COMP ON TRAIN_MOD.TRM_TRC_SEQ=TRAIN_COMP.TRC_SEQ_NO
>>where TC_PUB_ED IS TRUE OR TC_SEQ_NO IS NULL
>
>Can you show us the table schemas?
>
>Also, I think it's a good idea to qualify the columns in the WHERE
>clause, to prevent any possible ambiguity. Without seeing the table
>definitions I'm only guessing, but is it possible that these are
>doing something other than what you expect?
>
>Ray.
>
>PS - I personally find all-caps SQL very hard to read. :-)
>
>--
>Raymond O'Donnell :: Galway :: Ireland
>rod@iol.ie
>
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