asked on SQL join 3 tables & show all rows from one
Using mysql 5.5 but don't think that matters...
I have 3 tables
accounts
|a_id|StoreName|Address etc
products_accounts
|pa_id|p_fk|a_fk|
products
|p_id|UPC|ProdName| etc
some accounts have multiple products associated with them, some don't have any.
I need a query to return all accounts with associated products
result
----------------
a_id|StoreName | UPC | ProdName
1234 | Bob's Mart |12345 | WidgetA |
1235 | Bob's Mart |22345 | WidgetB |
1256 | Smart Mart |12345 | WidgetA |
3321 | Kwik Mart | null | null
I've tried a few combinations of left & right joins but can't seem to get it right.
I'm doing this in coldfusion so I can nest the product query within a store loop but Is this do-able with joins (or unions)??
I have 3 tables
accounts
|a_id|StoreName|Address etc
products_accounts
|pa_id|p_fk|a_fk|
products
|p_id|UPC|ProdName| etc
some accounts have multiple products associated with them, some don't have any.
I need a query to return all accounts with associated products
result
----------------
a_id|StoreName | UPC | ProdName
1234 | Bob's Mart |12345 | WidgetA |
1235 | Bob's Mart |22345 | WidgetB |
1256 | Smart Mart |12345 | WidgetA |
3321 | Kwik Mart | null | null
I've tried a few combinations of left & right joins but can't seem to get it right.
I'm doing this in coldfusion so I can nest the product query within a store loop but Is this do-able with joins (or unions)??
MySQL ServerDatabasesMicrosoft SQL Server
Last Comment
SidFishes
select allaccounts
from accounts left join products
ON t1.id = t2.id -- this will return all accounts , if you need
--you can more tables using the left join all the way.
union
select allaccounts
from accounts join products ON t1.id = t2.id -- this will return accounts with products
from accounts left join products
ON t1.id = t2.id -- this will return all accounts , if you need
--you can more tables using the left join all the way.
union
select allaccounts
from accounts join products ON t1.id = t2.id -- this will return accounts with products
ASKER
Rusty, I basically had what you've posted, and I now realize (I think) the reason it isn't working is that only accounts that have products associated with them are even -in- products_accounts table so the join can't work (as I was hoping)
I get products by accounts but if the account has no products associated with it, (ie: not in products_accounts table) then they don't show.
I think the only way to do this is in 2 parts. Unless someone has any other ideas.
I get products by accounts but if the account has no products associated with it, (ie: not in products_accounts table) then they don't show.
I think the only way to do this is in 2 parts. Unless someone has any other ideas.
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ASKER
OK that's doing the trick...brutally slow however (28secs to return 15k rows). I guess that's the problem with Union?
If I was just returning 1 row it would be ok but I'm doing proximity lookups based on lat/lon and can have up to 50 store locations in an area.
Going to have to try something else I think. Unless you have any other suggestions, I'll award pts & close the q..
If I was just returning 1 row it would be ok but I'm doing proximity lookups based on lat/lon and can have up to 50 store locations in an area.
Going to have to try something else I think. Unless you have any other suggestions, I'll award pts & close the q..
try this
Select a_id, StoreName , UPC , ProdName
from accounts Left outer join products_accounts
on a_id = a_fk
Left outer join products on p_id = p_fk
Select a_id, StoreName , UPC , ProdName
from accounts Left outer join products_accounts
on a_id = a_fk
Left outer join products on p_id = p_fk
with table references included :-)
SELECT accounts.a_id, accounts.StoreName , products.UPC , products.ProdName
FROM accounts
LEFT OUTER JOIN products_accounts ON accounts.a_id = products_accounts.a_fk
LEFT OUTER JOIN products ON products_accounts.p_fk = products.p_id
SELECT accounts.a_id, accounts.StoreName , products.UPC , products.ProdName
FROM accounts
LEFT OUTER JOIN (
SELECT DISTINCT
products_accounts.a_fk, products_accounts.p_fk
FROM products_accounts
) ap ON accounts.a_id = ap.a_fk
LEFT OUTER JOIN products ON ap.p_fk = products.p_id
ASKER
apologies...ended up using CF for the solution and forgot this was open.
Paul & appari - the left outer joins work, but they are even slower than the UNION (38 vs 28 seconds)
Pts to Rusty for first solution even though it's not practical in this instance due to the query time issue.
Paul & appari - the left outer joins work, but they are even slower than the UNION (38 vs 28 seconds)
Pts to Rusty for first solution even though it's not practical in this instance due to the query time issue.
FROM accounts t1
INNER JOIN products_accounts t2
ON t1.a_id = t2.a_fk
LEFT JOIN products t3
ON t2.p_fk = t3.p_id
unless I am missing something about your tables that should return what you want.