SQL Server date range and outer join - sql

I'm trying to do a simple aggregate query to total some results for users in a date range. I want to select ALL users, and if they don't have appropriate records the query should just return 0 for them.
The problem is, even with a right outer join on the table selecting the user IDs it only selects users that exist in that date range of the left table...
Here is the query:
select B.fld_strcode, sum(ISNULL(fld_val, 0)) as res
from tbl_transproc A right outer join tbl_pr B on A.fld_int_id = B.fld_auto_int_id
where A.fld_dtmservicedate between '2012-04-01' and '2012-05-01'
and B.fld_bytprtypeid = 1
group by B.fld_strcode
This query returns 13 rows. The query to select just the IDs(fld_strcode) returns 25 unique results. I want it to return 25 rows (for each ID), and the ones without values just to have a value of 0. If I take out the date range (go through all results in the table) then it works for all users, which makes sense because over all time all users will have at least one record in the table. Some users won't have a record for some months, and when this is the case I need it to just return 0 for them.
Any ideas on how I can achieve that.

When filtering outer join one must remember to do it in join itself, otherwise one ends up with masked inner join:
select B.fld_strcode, sum(ISNULL(fld_val, 0)) as res
from tbl_transproc A
right outer join tbl_pr B
on A.fld_int_id = B.fld_auto_int_id
AND A.fld_dtmservicedate between '2012-04-01' and '2012-05-01'
where B.fld_bytprtypeid = 1
group by B.fld_strcode
I would switch tables so I get left join, because in more complex queries it gets unreadable, especially if you mix right and left joins, as query designer likes to do.

Related

Query with Left outer join and group by returning duplicates

To begin with, I have a table in my db that is fed with SalesForce info. When I run this example query it returns 2 rows:
select * from SalesForce_INT_Account__c where ID_SAP_BAYER__c = '3783513'
When I run this next query on the same table I obtain one of the rows, which is what I need:
SELECT MAX(ID_SAP_BAYER__c) FROM SalesForce_INT_Account__c where ID_SAP_BAYER__c = '3783513' GROUP BY ID_SAP_BAYER__c
Now, I have another table (PedidosEspecialesZarateCabeceras) which has a field (NroClienteDireccionEntrega) that I can match with the field I've been using in the SalesForce table (ID_SAP_BAYER__c). This table has a key that consists of just 1 field (NroPedido).
What I need to do is join these 2 tables to obtain a row from PedidosEspecialesZarateCabeceras with additional fields coming from the SalesForce table, and in case those additional fields are not available, they should come as NULL values, so for that im using a LEFT OUTER JOIN.
The problem is, since I have to match NroClienteDireccionEntrega and ID_SAP_BAYER__c and there's 2 rows in the salesforce table with the same ID_SAP_BAYER__c, my query returns 2 duplicate rows from PedidosEspecialesZarateCabeceras (They both have the same NroPedido).
This is an example query that returns duplicates:
SELECT
cab.CUIT AS CUIT,
convert(nvarchar(4000), cab.NroPedido) AS NroPedido,
sales.BillingCity__c as Localidad,
sales.BillingState__c as IdProvincia,
sales.BillingState__c_Desc as Provincia,
sales.BillingStreet__c as Calle,
sales.Billing_Department__c as Distrito,
sales.Name as RazonSocial,
cab.NroCliente as ClienteId
FROM PedidosEspecialesZarateCabeceras AS cab WITH (NOLOCK)
LEFT OUTER JOIN
SalesForce_INT_Account__c AS sales WITH (NOLOCK) ON
cab.NroClienteDireccionEntrega = sales.ID_SAP_BAYER__c
and sales.ID_SAP_BAYER__c in
( SELECT MAX(ID_SAP_BAYER__c)
FROM SalesForce_INT_Account__c
GROUP BY ID_SAP_BAYER__c
)
WHERE cab.NroPedido ='5320'
Even though the join has MAX and Group By, this returns 2 duplicate rows with different SalesForce information (Because of the 2 salesforce rows with the same ID_SAP_BAYER__c), which should not be possible.
What I need is for the left outer join in my query to pick only ONE of the salesforce rows to prevent duplication like its happening right now. For some reason the select max with the group by is not working.
Maybe I should try to join this tables in a different way, can anyone give me some other ideas on how to join the two tables to return just 1 row? It doesnt matter if the SalesForce row that gets picked out of the 2 isn't the correct one, I just need it to pick one of them.
Your IN clause is not actually doing anything, since...
SELECT MAX(ID_SAP_BAYER__c)
FROM SalesForce_INT_Account__c
GROUP BY ID_SAP_BAYER__c
... returns all possible IDSAP_BAYER__c values. (The GROUP BY says you want to return one row per unique ID_SAP_BAYER__c and then, since your MAX is operating on exactly one unique value per group, you simply return that value.)
You will want to change your query to operate on a value that is actually different between the two rows you are trying to differentiate (probably the MAX(ID) for the relevant ID_SAP_BAYER__c). Plus, you will want to link that inner query to your outer query.
You could probably do something like:
...
LEFT OUTER JOIN
SalesForce_INT_Account__c sales
ON cab.NroClienteDireccionEntrega = sales.ID_SAP_BAYER__c
and sales.ID in
(
SELECT MAX(ID)
FROM SalesForce_INT_Account__c sales2
WHERE sales2.ID_SAP_BAYER__c = cab.NroClienteDireccionEntrega
)
WHERE cab.NroPedido ='5320'
By using sales.ID in ... SELECT MAX(ID) ... instead of sales.ID_SAP_BAYER__c in ... SELECT MAX(ID_SAP_BAYER__c) ... this ensures you only match one of the two rows for that ID_SAP_BAYER__c. The WHERE sales2.ID_SAP_BAYER__c = cab.NroClienteDireccionEntrega condition links the inner query to the outer query.
There are multiple ways of doing the above, especially if you don't care which of the relevant rows you match on. You can use the above as a starting point and make it match your preferred style.
An alternative might be to use OUTER APPLY with TOP 1. Something like:
SELECT
...
FROM PedidosEspecialesZarateCabeceras AS cab
OUTER APPLY(
SELECT TOP 1 *
FROM SalesForce_INT_Account__c s1
WHERE cab.NroClienteDireccionEntrega = s1.ID_SAP_BAYER__c
) sales
WHERE cab.NroPedido ='5320'
Without an ORDER BY the match that TOP 1 chooses will be arbitrary, but I think that's what you want anyway. (If not, you could add an ORDER BY).

How to LEFT JOIN two simple tables but not throwing away data from the second table? [duplicate]

I am trying to get the number of page opens on a per day basis using the following query.
SELECT day.days, COUNT(*) as opens
FROM day
LEFT OUTER JOIN tracking ON day.days = DAY(FROM_UNIXTIME(open_date))
WHERE tracking.open_id = 10
GROUP BY day.days
The output I get it is this:
days opens
1 9
9 2
The thing is, in my day table, I have a single column that contains the number 1 to 30 to represent the days in a month. I did a left outer join and I am expecting to have all days show on the days column!
But my query is doing that, why might that be?
Nanne's answer given explains why you don't get the desired result (your WHERE clause removes rows), but not how to fix it.
The solution is to change WHERE to AND so that the condition is part of the join condition, not a filter applied after the join:
SELECT day.days, COUNT(*) as opens
FROM day
LEFT OUTER JOIN tracking
ON day.days = DAY(FROM_UNIXTIME(open_date))
AND tracking.open_id = 10
GROUP BY day.days
Now all rows in the left table will be present in the result.
You specify that the connected tracking.open_id must be 10. For the other rows it will be NULL, so they'll not show up!
The condition is in the WHERE clause. After joining the tables the WHERE conditions are evaluated to filter out everything matching the criteria.Thus anything not matching tracking.open_id = 10 gets discarded.
If you want to apply this condition while joining the two tables, a better way is to use it with the ON clause (i.e. joining condition) than the entire dataset condition.

Can't seem to get an outer join working on informix [duplicate]

I am trying to get the number of page opens on a per day basis using the following query.
SELECT day.days, COUNT(*) as opens
FROM day
LEFT OUTER JOIN tracking ON day.days = DAY(FROM_UNIXTIME(open_date))
WHERE tracking.open_id = 10
GROUP BY day.days
The output I get it is this:
days opens
1 9
9 2
The thing is, in my day table, I have a single column that contains the number 1 to 30 to represent the days in a month. I did a left outer join and I am expecting to have all days show on the days column!
But my query is doing that, why might that be?
Nanne's answer given explains why you don't get the desired result (your WHERE clause removes rows), but not how to fix it.
The solution is to change WHERE to AND so that the condition is part of the join condition, not a filter applied after the join:
SELECT day.days, COUNT(*) as opens
FROM day
LEFT OUTER JOIN tracking
ON day.days = DAY(FROM_UNIXTIME(open_date))
AND tracking.open_id = 10
GROUP BY day.days
Now all rows in the left table will be present in the result.
You specify that the connected tracking.open_id must be 10. For the other rows it will be NULL, so they'll not show up!
The condition is in the WHERE clause. After joining the tables the WHERE conditions are evaluated to filter out everything matching the criteria.Thus anything not matching tracking.open_id = 10 gets discarded.
If you want to apply this condition while joining the two tables, a better way is to use it with the ON clause (i.e. joining condition) than the entire dataset condition.

SELECT FROM inner query slowdown

We have two very similar queries, one takes 22 seconds the other takes 6 seconds. Both use an inner select, have the exact same outer columns and outer joins. The only difference is the inner select that the outer query is using to join in on.
The inner query when run alone executes in 100ms or less in both cases and returns the EXACT SAME data.
Both queries as a whole have a lot of room for improvement, but this particular oddity is really puzzling to us and we just want to understand why. To me it would seem the inner query should be executed once in 100ms then the outer stuff happens. I have a feeling the inner select may be executed multiple times.
Query that takes 6 seconds:
SELECT {whole bunch of column names}
FROM (
SELECT projectItems.* FROM projectItems
WHERE projectItems.isActive = 1
ORDER BY projectItemsID ASC
OFFSET 0 ROWS FETCH NEXT 1 ROWS ONLY
) projectItems
LEFT JOIN categories
ON projectItems.fk_category = categories.categoryID
...{more joins}
Query that takes 22 seconds:
SELECT {whole bunch of column names}
FROM (
SELECT projectItems.* FROM projectItems
WHERE projectItems.isActive = 1
AND projectItemsID = 6539
) projectItems
LEFT JOIN categories
ON projectItems.fk_category = categories.categoryID
...{more joins}
For every row in your projectItems table, in the second function, you search two columns instead of one. If projectItemsID isn't the primary key or if it isn't indexed, it takes longer to parse an extra column.'
If you look at the sizes of the tables and the number of rows each query returns, you can calculate how many comparisons need to be made for each of the queries.
I believe that you're right that the inner query is being run for every single row that is being left joined with categories.
I can't find a proper source on it right now, but you can easily test this by doing something like this and comparing the run times. Here, we can at least be sure that the inner query is only running one time. (sorry if any syntax is incorrect, but you'll get the general idea):
DECLARE #innerQuery TABLE ( [all inner query columns here] )
INSERT INTO #innerQuery
SELECT projectItems.* FROM projectItems
WHERE projectItems.isActive = 1
AND projectItemsID = 6539
SELECT {whole bunch of field names}
FROM #innerQuery as IQ
LEFT JOIN categories
ON IQ.fk_category = categories.categoryID
...{more joins}

Outer join on multiple tables on SQL Server

I'm writing a recursive algorithm. It's taking data from 4 periods in the last year, and creating a resultset.
The issue is that not all scenarios return 4 periods.
So, I've done an set of 4 selects on the table, used an outer join to connect them. Their joined on the PK. However, they're all joined to the first datapoint. Sometimes this datapoint doesn't exist, which throws a wrench in my join.
Is there an easy way to do a full outer join on 4 tables using a PK with doing 16 where clauses and outer joining them with (+)
Actually, does (+) even work on sql server?
Thanks,
Eric
You should first create a complete dataset containing all periods in the previous year. *You could do this by using something like SELECT DISTINCT PERIOD FROM (SELECT PERIOD FROM SetA union SELECT PERIOD FROM SetB UNION SELECT PERIOD FROM SETC etc...) AS COMPLETESET"
Then left join against the COMPLETESET all other datasets on period.
The data points that do not exist in the joins will return null values.