Why do these SQL Server queries produce different outcomes? - sql-server

DATABASE: Adventure Works 2017
Query #1:
select
c.CustomerID, c.FirstName, c.EmailAddress,
a.AddressID as addrId, addr.AddressLine1 as address
from
[AdventureWorksLT2017].[SalesLT].[Customer] c
left join
(
[AdventureWorksLT2017].[SalesLT].[CustomerAddress] a
inner join
[AdventureWorksLT2017].[SalesLT].[Address] addr
on addr.AddressID = a.AddressID
)
on c.CustomerID=a.CustomerID
where
c.EmailAddress = 'orlando0#adventure-works.com';
This is the result:
https://i.stack.imgur.com/hJlmQ.png
Query #2
select
c.CustomerID, c.FirstName, c.EmailAddress,
a.AddressID as addrId, addr.AddressLine1 as address
from
[AdventureWorksLT2017].[SalesLT].[Customer] c
left join
[AdventureWorksLT2017].[SalesLT].[CustomerAddress] a
on a.CustomerID = c.CustomerID
inner join
[AdventureWorksLT2017].[SalesLT].[Address] addr
on addr.AddressID = a.AddressID
where
c.EmailAddress = 'orlando0#adventure-works.com';
This is the result of query #2:
https://i.stack.imgur.com/XwOdg.png
The desired result I want is the one from query #1, but I tried with the second query and I thought that it will produce the same result - but ...
Can anyone explain why ?

The answer is very simple, it's all about the join ordering.
Starting with the second version, we do the following steps
Take all Customer
Left join their CustomerAddress, so none of the previous rows have been removed
Inner join Address to steps 1 and 2, which means only rows that already have a match will be in the resultset
Whereas in version one:
Take all Customer
Take all CustomerAddress...
...Inner join Address to step 2 only, which means only CustomerAddress rows that have a match with Address will be in the resultset
But then left join the whole result of 2 and 3, so none of step 1 Customer rows have been removed
This means that the first version will not remove Customer rows which do not have an Address, whereas version two will do so. Version one is more likely the correct intention
Important note:
The parenthesis themselves are not what does this. It's the fact that the inner join is nested between left join and its respective on. In other words, it's the order of the joins that counts.

Related

Find third largest quote ever created for each of the accounts in the EC1 area

Can anyone help I'm new to SQL and trying to figure out the below question see image for the table structure;
Question = Select account name, contact last name, case number, quote number, quote date and quote value for the f third-largest quote ever created for each of the accounts in the EC1 area
So far I got;
Select
a.accountname, cc.lastname, c.casenumber,
q.quotenumber, q.quotedate, q.quotevalue
from
TBL_Quote q
Left join
TBL_case c On q.caseid = c.caseid
Left join
tbl_contact cc On c.contactID = cc. contactID
Left join
tbl_account a On a.accountid = cc.accountid
Where
left(a.postcode, 3) like 'EC1'
and for the third:
SELECT TOP 1 value
FROM
(SELECT DISTINCT TOP 3 value
FROM tbl_quote
ORDER BY value DESC) a
ORDER BY value
I can't seem to combine the top 3 and the query is it best to overpartion by ?
I would suggest joins and a row-limiting clause:
select ac.accountName, co.lastName, ca.caseNumber, qu.quoteNumber
from tbl_account ac
inner join tbl_contact co on co.accountId = ac.accountId
inner join tbl_case ca on ca.contactId = co.contactId
inner join tbl_quote qu on qu.caseId = ca.quoteId
where ac.postcode like 'EC1%'
order by len(qu.value) desc
offset 2 rows fetch next 1 row only

Why do I have duplicate records in my JOIN

I am retrieving data from table ProductionReportMetrics where I have column NetRate_QuoteID. Then to that result set I need to get Description column.
And in order to get a Description column, I need to join 3 tables:
NetRate_Quote_Insur_Quote
NetRate_Quote_Insur_Quote_Locat
NetRate_Quote_Insur_Quote_Locat_Liabi
But after that my premium is completely off.
What am I doing wrong here?
SELECT QLL.Description,
QLL.ClassCode,
prm.NetRate_QuoteID,
QL.LocationID,
ISNULL(SUM(premium),0) AS NetWrittenPremium,
MONTH(prm.EffectiveDate) AS EffMonth
FROM ProductionReportMetrics prm
LEFT JOIN NetRate_Quote_Insur_Quote Q
ON prm.NetRate_QuoteID = Q.QuoteID
INNER JOIN NetRate_Quote_Insur_Quote_Locat QL
ON Q.QuoteID = QL.QuoteID
INNER JOIN NetRate_Quote_Insur_Quote_Locat_Liabi QLL
ON QL.LocationID = QLL.LocationID
WHERE YEAR(prm.EffectiveDate) = 2016 AND
CompanyLine = 'Ironshore Insurance Company'
GROUP BY MONTH(prm.EffectiveDate),
QLL.Description,
QLL.ClassCode,
prm.NetRate_QuoteID,
QL.LocationID
I think the problem in this table:
What Am I missing in this Query?
select
ClassCode,
QLL.Description,
sum(Premium)
from ProductionReportMetrics prm
LEFT JOIN NetRate_Quote_Insur_Quote Q ON prm.NetRate_QuoteID = Q.QuoteID
LEFT JOIN NetRate_Quote_Insur_Quote_Locat QL ON Q.QuoteID = QL.QuoteID
LEFT JOIN
(SELECT * FROM NetRate_Quote_Insur_Quote_Locat_Liabi nqI
JOIN ( SELECT LocationID, MAX(ClassCode)
FROM NetRate_Quote_Insur_Quote_Locat_Liabi GROUP BY LocationID ) nqA
ON nqA.LocationID = nqI.LocationID ) QLL ON QLL.LocationID = QL.LocationID
where Year(prm.EffectiveDate) = 2016 AND CompanyLine = 'Ironshore Insurance Company'
GROUP BY Q.QuoteID,QL.QuoteID,QL.LocationID
Now it says
Msg 8156, Level 16, State 1, Line 14
The column 'LocationID' was specified multiple times for 'QLL'.
It looks like DVT basically hit on the answer. The only reason you would get different amounts(i.e. duplicated rows) as a result of a join is that one of the joined tables is not a 1:1 relationship with the primary table.
I would suggest you do a quick check against those tables, looking for table counts.
--this should be your baseline count
SELECT COUNT(*)
FROM ProductionReportMetrics
GROUP BY MONTH(prm.EffectiveDate),
prm.NetRate_QuoteID
--this will be a check against the first joined table.
SELECT COUNT(*)
FROM NetRate_Quote_Insur_Quote Q
WHERE QuoteID IN
(SELECT NetRate_QuoteID
FROM ProductionReportMetrics
GROUP BY MONTH(prm.EffectiveDate),
prm.NetRate_QuoteID)
Basically you will want to do a similar check against each of your joined tables. If any of the joined tables are part of the grouping statement, make sure they are also in the grouping of the count check statement. Also make sure to alter the WHERE clause of the check count statement to use the join clause columns you were using.
Once you find a table that returns the incorrect number of rows, you will have your answer as to what table is causing the problem. Then you will just have to decide how to limit that table down to distinct rows(some type of aggregation).
This advice is really just to show you how to QA this particular query. Break it up into the smallest possible parts. In this case, we know that it is a join that is causing the problem, so take it one join at a time until you find the offender.

MS SQL Table Joins - Multiple Tables

I am new to MS SQL and am having trouble joining 4 tables within a query.
I am trying to join Orders, Order Lines, Client, and Picked tables to create a query to show quantity ordered and picked for a client. If I comment out the last inner join for Picked, I get the correct results. When I include the inner join for Picked the query returns results but data that should be in the Picked fields is NULL. One order line can have 1 or more Picked lines.
SELECT W_Warehouse, OH.OrderID, OH.RequiredDate, C.Client, OL.LineNbr, OL.QtyOrd, P.QtyPick
FROM Order
INNER JOIN Warehouse on Order.OH_WHS = Warehouse.W_PK
INNER JOIN Client on Order.O_Client = Client.C_PK
INNER JOIN OrderLine on Order.O_PK = OrderLine.OL_PK
INNER JOIN Picked on OrderLine.O_PK = Picked.P_PK
WHERE C.CLIENT = 'WENDYS'
Without knowing the data in the tables it is difficult to answer precisely.
But as you say you have 1+ rows in the Picked table, you probably want to do aggregation with GROUP BY and SUM()
Maybe this is what you're looking for:
SELECT
W.W_Warehouse,
OH.OrderID,
OH.RequiredDate,
C.Client,
OL.LineNbr,
OL.QtyOrd,
P.QtyPick
FROM
Order OH
INNER JOIN Warehouse W on OH.OH_WHS = W.W_PK
INNER JOIN Client C on OH.O_Client = C.C_PK
INNER JOIN OrderLine OL on OH.O_PK = OL.OL_PK
CROSS APPLY (
select sum(QtyPick) as QtyPick
from Picked P
where OL.O_PK = P.P_PK
) P
WHERE
C.CLIENT = 'WENDYS'
It calculates the sum of QtyPick separately so it doesn't increase the number of lines in the result.

How to join one select with another when the first one not always returns a value for specific row?

I have a complex query to retrieve some results:
EDITED QUERY (added the UNION ALL):
SELECT t.*
FROM (
SELECT
dbo.Intervencao.INT_Processo, analista,
ETS.ETS_Sigla, ATC.ATC_Sigla, PAT.PAT_Sigla, dbo.Assunto.SNT_Peso,
CASE
WHEN ETS.ETS_Sigla = 'PE' AND (PAT.PAT_Sigla = 'LIB' OR PAT.PAT_Sigla = 'LBR') THEN (0.3*SNT_Peso)
WHEN ETS.ETS_Sigla = 'CD' THEN (0.3*SNT_Peso)*0.3
ELSE SNT_Peso
END AS PESOAREA,
CASE
WHEN a.max_TEA_FimTarefa IS NULL THEN a.max_TEA_InicioTarefa
ELSE a.max_TEA_FimTarefa
END AS DATA_INICIO_TERMINO,
ROW_NUMBER() OVER (PARTITION BY ATC.ATC_Sigla, a.SRV_Id ORDER BY TEA_FimTarefa DESC) AS seqnum
FROM dbo.Tarefa AS t
INNER JOIN (
SELECT
MAX(dbo.TarefaEtapaAreaTecnica.TEA_InicioTarefa) AS max_TEA_InicioTarefa,
MAX (dbo.TarefaEtapaAreaTecnica.TEA_FimTarefa) AS max_TEA_FimTarefa,
dbo.Pessoa.PFJ_Descri AS analista, dbo.AreaTecnica.ATC_Id, dbo.Tarefa.SRV_Id
FROM dbo.TarefaEtapaAreaTecnica
LEFT JOIN dbo.Tarefa ON dbo.TarefaEtapaAreaTecnica.TRF_Id = dbo.Tarefa.TRF_Id
LEFT JOIN dbo.AreaTecnica ON dbo.TarefaEtapaAreaTecnica.ATC_Id = dbo.AreaTecnica.ATC_Id
LEFT JOIN dbo.ServicoAreaTecnica ON dbo.TarefaEtapaAreaTecnica.ATC_Id = dbo.ServicoAreaTecnica.ATC_Id
AND dbo.Tarefa.SRV_Id = dbo.ServicoAreaTecnica.SRV_Id
INNER JOIN dbo.Pessoa ON dbo.Pessoa.PFJ_Id = dbo.ServicoAreaTecnica.PFJ_Id_Analista
GROUP BY dbo.AreaTecnica.ATC_Id, dbo.Tarefa.SRV_Id, dbo.Pessoa.PFJ_Descri
) AS a ON t.SRV_Id = a.SRV_Id
INNER JOIN dbo.TarefaEtapaAreaTecnica AS TarefaEtapaAreaTecnica_1 ON
t.TRF_Id = TarefaEtapaAreaTecnica_1.TRF_Id
AND a.ATC_Id = TarefaEtapaAreaTecnica_1.ATC_Id
AND a.max_TEA_InicioTarefa = TarefaEtapaAreaTecnica_1.TEA_InicioTarefa
LEFT JOIN AreaTecnica ATC ON TarefaEtapaAreaTecnica_1.ATC_Id = ATC.ATC_Id
LEFT JOIN Etapa ETS ON TarefaEtapaAreaTecnica_1.ETS_Id = ETS.ETS_Id
LEFT JOIN ParecerTipo PAT ON TarefaEtapaAreaTecnica_1.PAT_Id = PAT.PAT_Id
LEFT OUTER JOIN dbo.Servico ON a.SRV_Id = dbo.Servico.SRV_Id
INNER JOIN dbo.Intervencao ON dbo.Servico.INT_Id = dbo.Intervencao.INT_Id
LEFT JOIN dbo.Assunto ON dbo.Servico.SNT_Id = dbo.Assunto.SNT_Id
) t
The result is following:
It works good, the problem is that I was asked that if when a row is not present on this query, it must contain values from another table (ServicoAreaTecnica), so I got this query for the other table based on crucial information of the first query. So if I UNION ALL I get this:
Query1 +
UNION ALL
SELECT INN.INT_Processo,
PES.PFJ_Descri,
NULL, --ETS.ETS_Sigla,
ART.ATC_Sigla,
NULL ,--PAT.PAT_Sigla,
ASS.SNT_Peso,
NULL, --PESOAREA
NULL, --DATA_INICIO_TERMINO
NULL --seqnum
FROM dbo.ServicoAreaTecnica AS SAT
INNER JOIN dbo.AreaTecnica AS ART ON ART.ATC_Id = SAT.ATC_Id
INNER JOIN dbo.Servico AS SER ON SER.SRV_Id = SAT.SRV_Id
INNER JOIN dbo.Assunto AS ASS ON ASS.SNT_Id = SER.SNT_Id
INNER JOIN dbo.Intervencao AS INN ON INN.INT_Id = SER.INT_Id
INNER JOIN dbo.Pessoa AS PES ON PES.PFJ_Id = SAT.PFJ_Id_Analista
The result is following:
So what I want to do is to remove row number 1 because row number 2 exists on the first query, I think I got it explained better this time. The result should be only row number 1, row number 2 would appear only if query 1 doesn't retrieve a row for that particular INN.INT_Processo.
Thanks!
Ok, there are two ways to reduce your record set. Given that you've already written the code to produce the table with the extra rows, it might be easiest to just add code to reduce that:
Select * from
(Select *
, Row_Number() over
(partition by IntProcesso, Analista order by ISNULL(seqnum, 0) desc) as RN
from MyResults) a
where RN = 1
This will assign row_number 1 to any rows that came from your first query, or to any rows from the second query that do not have matches in the first query, then filter out extra rows.
You could also use outer joins with isnull or coalesce, as others have suggested. Something like this:
Select ISNULL(a.IntProcesso, b.IntProcesso) as IntProcesso
, ISNULL(a.Analista, b.Analista) as Analista
, ISNULL(a.ETSsigla, b.ETSsigla) as ETSsigla
[repeat for the rest of your columns]
from Table1 a
full outer join Table2 b
on a.IntProcesso = b.IntProcesso and a.Analista = b.Analista
Your code is hard to read, because of the lengthy names of everything (and to be honest, the fact that they're in a language I don't speak also makes it a lot harder).
But how about: replacing your INNER JOINs with LEFT JOINs, adding more LEFT JOINs to draw in the alternative tables, and introducing ISNULL clauses for each variable you want in the results?
If you do something like ... Query1 Right Join Query2 On ... that should get only the rows in Query2 that don't appear in Query 1.

Inner Join and Left Join in same sql query

I'm trying to perform inner join and then left join in same sql query.
But the left join is not working. It is not showing the null values
I've two tables EVENT_INVITATIONS and USERINFO which has 2 records when joined.
so, the join query goes like this :
select * from [UandMePROD].[dbo].EVENT_INVITATIONS EI
join [UandMePROD].[dbo].USERINFO UI on EI.USER_ID = UI.USER_ID and EI.EVENT_ID=11033
It gives out 2 records.
So, I'm performing a left join with another table CLIENT_CONTACTS which has only 1 matching record in it.
So, actually it should show the null value to the unmatched record. but it is not showing the second record. It is showing only 1 record which is matched(join)
My failed sql query :
select * from [UandMePROD].[dbo].EVENT_INVITATIONS EI
join [UandMePROD].[dbo].USERINFO UI on EI.USER_ID = UI.USER_ID
left join CLIENT_CONTACTS CC on UI.MOBILENO=CC.MOBILE_NUMBER
where cc.CLIENT_ID=20111 and EI.EVENT_ID=11033
can you please tell me where I'm doing mistake?
I need the 2 records.
Since you are doing a left join, cc.CLIENT_ID is null for all the values which only exist in CLIENT_CONTACTS and your where clause Where cc.CLIENT_ID = 20111
converts your LEFT JOIN into INNER JOIN. Adding this filter in ON clause solves the issue.
select *
from [UandMePROD].[dbo].EVENT_INVITATIONS EI
inner join [UandMePROD].[dbo].USERINFO UI on EI.[USER_ID] = UI.[USER_ID]
left join CLIENT_CONTACTS CC on UI.MOBILENO = CC.MOBILE_NUMBER
and cc.CLIENT_ID = 20111
where EI.EVENT_ID=11033
You should not specify EI.EVENT_ID on WHERE clause. Those limit your results after the join. You should specify EI.EVENT_ID in an ON clause.
select * from [UandMePROD].[dbo].EVENT_INVITATIONS EI join [UandMePROD].[dbo].USERINFO UI on EI.USER_ID = UI.USER_ID AND (EI.EVENT_ID=11033 or EI.EVENT_ID is null) left join CLIENT_CONTACTS CC on UI.MOBILENO=CC.MOBILE_NUMBER where cc.CLIENT_ID=20111
Providing some suggestions,since it is not possible to say what is happening with out table data
Left join should show null values from output of first inner join eventhough there are no mobile number matches,so try removing where condition and see if you are getting any result

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