问题
I have a query that uses two SELECT statements that are combined using a UNION ALL. Both statements pull data from similar tables to populate the query results. I am attempting to remove the "semi-duplicate" rows from the query, but am having issues doing so.
My query is the following:
SELECT DISTINCT *
FROM
(
SELECT
TeamNum = CASE
WHEN T.TeamName = 'Alpha Team'
THEN '1'
WHEN T.TeamName IN ('Bravo Team', 'Charlie Team')
THEN '2'
WHEN T.TeamName = 'Delta Team'
THEN '3'
ELSE '<Undefined>'
END,
P.PatientLastName AS LastName,
P.PatientFirstName AS FirstName,
R.PrimaryCity AS City,
ReimbursorName = CASE
WHEN RE.ReimbursorDescription = 'Medicare'
Then 'R1'
WHEN RE.ReimbursorDescription = 'Medicaid'
Then 'R2'
ELSE 'R3'
END,
P.PatientID AS PatientID
FROM
PatReferrals PR LEFT JOIN Patient P ON PR.PatientID = P.PatientID,
Patient P LEFT OUTER JOIN Rolodex R ON P.RolodexID = R.RolodexID,
PatReferrals PR LEFT OUTER JOIN PatReimbursors PRE ON PR.PatientID = PRE.PatientID,
PatReimbursors PRE LEFT OUTER JOIN Reimbursors RE ON PRE.ReimbursorID = RE.ReimbursorID,
PatReferrals PR FULL OUTER JOIN Teams T ON PR.TeamID = T.TeamID,
WHERE
PR.ReferralDate BETWEEN GETDATE()-4 AND GETDATE()-1
AND PR.Status <> 'R'
AND PRE.CoveragePriority = '1'
AND PRE.ExpirationDate IS NULL
UNION ALL
SELECT
TeamNum = CASE
WHEN T.TeamName = 'Alpha Team'
THEN '1'
WHEN T.TeamName IN ('Bravo Team', 'Charlie Team')
THEN '2'
WHEN T.TeamName = 'Delta Team'
THEN '3'
ELSE '<Undefined>'
END,
P.PatientLastName AS LastName,
P.PatientFirstName AS FirstName,
R.PrimaryCity AS City,
ReimbursorName = CASE
WHEN RE.ReimbursorDescription = 'Medicare'
Then 'E1'
WHEN RE.ReimbursorDescription = 'Medicaid'
Then 'E2'
ELSE 'E3'
END,
P.PatientID AS PatientID
FROM
PatReferrals PR LEFT JOIN Patient P ON PR.PatientID = P.PatientID,
Patient P LEFT OUTER JOIN Rolodex R ON P.RolodexID = R.RolodexID,
PatReferrals PR LEFT OUTER JOIN PatEligibilities PE ON PR.PatientID = PE.PatientID,
PatEligibilities PE LEFT OUTER JOIN Reimbursors RE ON PE.ReimbursorID = RE.ReimbursorID,
PatReferrals PR FULL OUTER JOIN Teams T ON PR.TeamID = T.TeamID,
WHERE
PR.ReferralDate BETWEEN GETDATE()-4 AND GETDATE()-1
AND PR.Status <> 'R'
AND PE.Status <> 'V'
AND PE.ApplicationDate BETWEEN DATE(PR.ReferralDate)-5 AND DATE('2100/01/01')
)
AS DUMMYTBL
ORDER BY
DUMMYTBL.LastName ASC,
DUMMYTBL.FirstName ASC
The results that I receive when I run the query is the following:
3 Doe Jane Town R1 19874
1 Roe John City R3 50016
1 Roe John City E1 50016
2 Smith Jane Town E3 33975
The data that I am needing to remove is duplicate rows based on a certain criteria once the results are brought in from the original query. Each person can only be listed once and they must have a single pay source (R1, R2, R3, E1, E2, E3). If there is a R#, than there cannot be a E# listed for that person. If there are no R#'s than an E# must be listed. As shown in my example results, line 2 and 3 have the same person listed, but two pay sources (R3 and E1).
How can I go about making each person have only one row shown using the criteria that I have listed?
EDIT: Modifed the SQL query to show the original variables from the WHERE clauses in order to show further detail on the query. The PatReimbursors and the PatEligibilities tables have similar data, but the criteria is different in order to pull the correct data.
回答1:
Your query does not make sense. I would start by eliminating the implicit cartesian product, generated by the , in the from clause.
My guess is that the from clause should be:
FROM
PatReferrals PR LEFT JOIN
Patient P
ON PR.PatientID = P.PatientID left outer join
Rolodex R
ON P.RolodexID = R.RolodexID left outer join
PatEligibilities PE
ON PR.PatientID = PE.PatientID left outer join
Reimbursors RE
ON PE.ReimbursorID = RE.ReimbursorID left outer join
Teams T ON PR.TeamID = T.TeamID
Once you do this, you may not need the union all or the select distinct. You may be able to put both the reimbursors and the eligibilities in the same query.
回答2:
Use a subquery or subqueries.
The overall query should be written using the following pattern:
Select Distinct [Person Data]
From PersonTable
left Join to otherTable1 -- add outer join for each table you need data from
On [Conditions that ensure join can generate only one row per person,
... and specify which of possibly many rows to get...]
Make sure the conditions eliminate any possibility for the join to generate more than one row from the other [outer] table per person row in in the person table,. This may (and often does) require that the join condition be based on a subquery, as, for example...
Select Distinct [Person Data]
From PersonTable p
left Join to employments e -- add outer join for each table you need data from
On e.PersonId = p.PersonId
and e.HireDate = (Select Max(hiredate) from employments
where personId = p.PersonId)
回答3:
After working with this for quite some time today, I found a solution to the problem that I was having. Here is the solution that works and pulls the correct information that I was needing:
SELECT DISTINCT
TeamNum,
LastName,
FirstName,
City,
ReimbursorName = CASE
WHEN max(ReimbursorName) IN ('R1', 'E1')
THEN '1'
WHEN max(ReimbursorName) IN ('R2', 'E2')
THEN '2'
ELSE '3'
END,
PatientID
FROM
(
SELECT
TeamNum = CASE
WHEN T.TeamName = 'Alpha Team'
THEN '1'
WHEN T.TeamName IN ('Bravo Team', 'Charlie Team')
THEN '2'
WHEN T.TeamName = 'Delta Team'
THEN '3'
ELSE '<Undefined>'
END,
P.PatientLastName AS LastName,
P.PatientFirstName AS FirstName,
R.PrimaryCity AS City,
ReimbursorName = CASE
WHEN RE.ReimbursorDescription = 'Medicare'
Then 'R1'
WHEN RE.ReimbursorDescription = 'Medicaid'
Then 'R2'
ELSE 'R3'
END,
P.PatientID AS PatientID
FROM
PatReferrals PR LEFT JOIN Patient P ON PR.PatientID = P.PatientID,
Patient P LEFT OUTER JOIN Rolodex R ON P.RolodexID = R.RolodexID,
PatReferrals PR LEFT OUTER JOIN PatReimbursors PRE ON PR.PatientID = PRE.PatientID,
PatReimbursors PRE LEFT OUTER JOIN Reimbursors RE ON PRE.ReimbursorID = RE.ReimbursorID,
PatReferrals PR FULL OUTER JOIN Teams T ON PR.TeamID = T.TeamID
WHERE
PR.ReferralDate BETWEEN GETDATE()-4 AND GETDATE()-1
AND PR.Status <> 'R'
AND PRE.CoveragePriority = '1'
AND PRE.ExpirationDate IS NULL
UNION ALL
SELECT
TeamNum = CASE
WHEN T.TeamName = 'Alpha Team'
THEN '1'
WHEN T.TeamName IN ('Bravo Team', 'Charlie Team')
THEN '2'
WHEN T.TeamName = 'Delta Team'
THEN '3'
ELSE '<Undefined>'
END,
P.PatientLastName AS LastName,
P.PatientFirstName AS FirstName,
R.PrimaryCity AS City,
ReimbursorName = CASE
WHEN RE.ReimbursorDescription = 'Medicare'
Then 'E1'
WHEN RE.ReimbursorDescription = 'Medicaid'
Then 'E2'
ELSE 'E3'
END,
P.PatientID AS PatientID
FROM
PatReferrals PR LEFT JOIN Patient P ON PR.PatientID = P.PatientID,
Patient P LEFT OUTER JOIN Rolodex R ON P.RolodexID = R.RolodexID,
PatReferrals PR LEFT OUTER JOIN PatEligibilities PE ON PR.PatientID = PE.PatientID,
PatEligibilities PE LEFT OUTER JOIN Reimbursors RE ON PE.ReimbursorID = RE.ReimbursorID,
PatReferrals PR FULL OUTER JOIN Teams T ON PR.TeamID = T.TeamID
WHERE
PR.ReferralDate BETWEEN GETDATE()-4 AND GETDATE()-1
AND PR.Status <> 'R'
AND PE.Status <> 'V'
AND PE.ApplicationDate BETWEEN DATE(PR.ReferralDate)-5 AND DATE('2100/01/01')
)
AS DUMMYTBL
GROUP BY
TeamNum,
LastName,
FirstName,
City,
PatientID
ORDER BY
DUMMYTBL.LastName ASC,
DUMMYTBL.FirstName ASC
Thanks for all the responses that were provided.
来源：https://stackoverflow.com/questions/15552152/sybase-sql-remove-semi-duplicates-from-query-results