Handle Complex Query - sql

Question

I have following tables with their columns
tbAgent :- Agent, AgentX, AgentCode, NIPRNumber, PhysicalAddressState,
SystemUser
tbBroker :- Broker, BusinessName, BrokerCode,SystemUser
tbCompany :- Company, CompanyX
tbSystemUser :- SystemUser FirstName, LastName, EmailAddress
tbProduct :- Product, ProductX, ProductCode, Jurisdiction, CompanyId
tbLicence :- Licence, LicenceNumber,DateIssued,ExpirationDate,Jurisdiction,
StateIssued, BrokerId, AgentId
tbCompanyAgent :- CompanyId, AgentId, ProductId, LicenseNumber,
LicenseIssueDate,LicenceExpirationDate
tbBrokerAgent :- BrokerId, AgentId
tbJurisdiction :- Jurisdiction, JurisdictionX
In this project, we store Agents, Agencies (Brokers) and Companies in tbAgent, tbBroker and tbCompany respectively. We store Company's Products in tbProduct.
Thr Agent's LicenseDetails are stored in tbLicence. Agent's are appointed to Agencies(Brokers) and these details are stored in tbBrokerAgent.
Also Agents are appointed to Companies and these details are stored in tbCompanyAgent. The Agents are appointed to Companies, if Company's product's Jurisdiction matched with the Agent's License's Resident State or Non Resident state.
Note that Agent's has two type of licences stored in tbLicence, one is Resident and other is Non Resident Licenses. If it is Resident License, then the column name "Jurisdiction" contains 0 and If it is Non Resident License, then it contain actual Jurisdiction Id of State. If it contains 0 then we have to consider Agent's PhysicalAddressState as ResidentState.
All jurisdictions (States) are present in tbJurisdiction.
Now I have to create a view where I have to fetch the following Information
CompanyX
CompanyCode
BrokerX
BrokerCode
AgentX
Agentcode
NIPRNumber
ProductX
ProductCode
State
LicenceNumber
EffectiveDate
ExpirationDate
I have tried the following query
SELECT a.AgentCode,sy.AgentName,L.Licence,L.LicenceNumber,DateIssued as EffectiveDate,L.ExpirationDate,J.JurisdictionX as State
From tbAgent as a
INNER JOIN tbLicence L ON L.AgentId=a.Agent
LEFT OUTER JOIN (SELECT Jurisdiction,JurisdictionX FROM tbJurisdiction) as j on j.Jurisdiction=
(
CASE WHEN ISNULL(L.Jurisdiction,'0')='0' THEN a.PhysicalAddressState
ELSE
L.Jurisdiction
END
)
LEFT OUTER JOIN (SELECT SystemUser, (FirstName + ' '+LastName) as AgentName FROM tbSystemUser ) as sy on sy.SystemUser=a.SystemUser
The above query is fetching the following information
AgentX
Agentcode
NIPRNumber
State
LicenceNumber
EffectiveDate
ExpirationDate
Excluding the following columns
CompanyX
CompanyCode
BrokerX
BrokerCode
ProductX
ProductCode
I am not able to tweak the above query for fetching the excluding Column's information because the query is getting complex to handle...
Please help me !!!

Answer 1

If the question is about complexity, I hope CTE-technique will be a good tip for you:
;WITH cteJur as
(
SELECT
Jurisdiction,
JurisdictionX
FROM tbJurisdiction j
),
cteSysUsr as
(
SELECT
SystemUser,
(FirstName + ' '+LastName) as AgentName
FROM tbSystemUser su
),
cteAgent as
(
SELECT
a.AgentCode, a.SystemUser,
L.Licence, L.LicenceNumber,
L.DateIssued as EffectiveDate, L.ExpirationDate,
CASE
WHEN ISNULL(L.Jurisdiction,'0')='0'
THEN a.PhysicalAddressState
ELSE L.Jurisdiction
END as Jurisdiction
FROM tbAgent as a
INNER JOIN tbLicence L ON L.AgentId=a.Agent
)
SELECT
a.AgentCode, sy.AgentName,
a.Licence, a.LicenceNumber,
a.EffectiveDate, a.ExpirationDate,
J.JurisdictionX as State
FROM tbAgent as a
LEFT JOIN cteJur as j on j.Jurisdiction = a.Jurisdiction
LEFT JOIN cteSysUsr as sy on sy.SystemUser = a.SystemUser
If you were looking where to include your "excluded columns" - add them into appropriate CTE and reference them in final select. You don't have to put every joined table into a subquery. Just join it and reference table's columns in select list, that's it. Just as described in the query above.

Answer 2

First, you appear to have a good following of the tables and how related. I have tried to implement them and get ALL columns from the respective table(s). You can strip out whatever you want.
Now, first, I want you to look at the FROM clause section. Think of this before getting the columns, especially in a complex query of a lot of tables being joined. Take each one to the next. I always try to do my joins with the first table (or alias) as the left-side of the ON clause and the JOINING TO as the right-side... Then, if something is nested under the second, I keep the indentation going so I see the literal correlations more directly and have less chance of getting confused.
from
FirstTable alias1
JOIN SecondTable alias2
on alias1.IDColumn = alias2.IDColumn
JOIN ThirdTable alias3
on alias2.OtherID = alias3.OtherID
Now, in the case of your Jurisdictions, there are 3 possible places it CAN originate from... The agent, product and the license. Because I do not know which version you specifically want, I applied LEFT-JOINs to each one respectively. This allows me to use the same table multiple times with different aliases. Then I grab each JurisdictionX and call it an appropriate "as" name in the result.
Finally, I build out all the field columns that are wanted. If you wanted to narrow the list of data (such as a single broker) then you just apply the WHERE criteria. Hopefully this makes a lot of sense and you can strip out the extra fields you may not care about.
SELECT
a.Agent,
a.AgentX,
a.AgentCode,
a.NIPRNumber,
a.PhysicalAddressState,
a.SystemUser,
( AgUser.FirstName + ' '+ AgUser.LastName) as AgentName,
AgUser.EmailAddress as AgentEMail,
b.Broker,
b.BusinessName,
b.BrokerCode,
b.SystemUser as BrokerUser,
( BrUser.FirstName + ' '+ BrUser.LastName) as BrokerName,
BrUser.EmailAddress as BrokerEMail,
l.License,
l.LicenseNumber,
l.DateIssued,
l.ExpirationDate,
l.Jurisdiction,
l.StateIssued,
ca.LicenseNumber as CA_LicenseNumber,
ca.LicenseIssueDate as LicenseIssueDate,
ca.LicenseExpirationDate as LicenseExpirationDate,
c.Company,
c.CompanyX,
p.ProductX,
p.ProductCode,
AgJuris.JurisdictionX as AgentJurisdiction,
LicJuris.Jurisdiction as LicenseJurisdiction,
ProdJuris.Jurisdiction as ProductJurisdiction
from
tbAgent a
JOIN tbSystemUser AgUser
ON a.SystemUser = ag.SystemUser
JOIN tbLicense l
ON a.Agent = l.AgentID
JOIN tbBroker B
ON l.BrokerID = B.BrokerID
JOIN tbSystemUser BrUser
ON b.SystemUser = br.SystemUser
LEFT JOIN tbJurisdiction LicJuris
ON ISNULL(L.Jurisdiction,'0') = LicJuris.Jurisdiction
JOIN tbCompanyAgent ca
ON a.Agent = ca.AgentID
JOIN tbCompany c
ON ca.CompanyID = c.Company
JOIN tbProduct p
ON ca.CompanyID = p.CompanyID
AND ca.ProductID = p.Product
LEFT JOIN tbJurisdiction ProdJuris
ON p.Jurisdiction = ProdJuris.Jurisdiction
LEFT JOIN tbJurisdiction AgJuris
ON a.PhysicalAddressState = AgJuris.Jurisdiction
Additionally, for the issue on Jurisdictions, since you have all 3 POSSIBLE, you could add a last column such as
COALESCE( LicJuris.Jurisdiction, AgJuris.JurisdictionX ) as WhichJurisdiction
or considering all 3...
COALESCE( LicJuris.Jurisdiction, COALESCE( ProdJuris.Jurisdiction , AgJuris.JurisdictionX )) as WhichJurisdiction
So, if the license jurisdiction is not available, grab the value from product jurisdiction, if not that, fall back to the agent's jurisdiction.