Need to select only patients who have not specific codes - sql

Question

I have here an issue in this sql - it will give me the rows that are not these diagnosis codes. But a patient can have them as well.
I need patients who do not have these 3 codes
V72.31', 'Z01.411', 'Z01.419' at all.
SELECT distinct "Vouchers"."Patient_ID"
FROM (("Ntier_70751"."PM"."Service_Diagnoses" "Service_Diagnoses"
INNER JOIN "Ntier_70751"."PM"."Services" "Services"
ON "Service_Diagnoses"."Service_ID"="Services"."Service_ID")
INNER JOIN "Ntier_70751"."PM"."Diagnosis_Codes" "Diagnosis_Codes"
ON "Service_Diagnoses"."Diagnosis_Code_ID"="Diagnosis_Codes"."Diagnosis_Code_ID")
INNER JOIN "Ntier_70751"."PM"."Vouchers" "Vouchers" ON "Services"."Voucher_ID"="Vouchers"."Voucher_ID"
WHERE "Diagnosis_Codes"."Diagnosis_Code" not in ('V72.31', 'Z01.411', 'Z01.419')

Answer 1

Your desired outcome is unclear.
This will show patients who have your "invalid" codes, so long as they have at least one code that is not in your exclusion list:
SELECT DISTINCT
v.Patient_ID
FROM
Ntier_70751.PM.Service_Diagnoses sd
INNER JOIN Ntier_70751.PM.Services s
ON sd.Service_ID = s.Service_ID
INNER JOIN Ntier_70751.PM.Diagnosis_Codes dc
ON sd.Diagnosis_Code_ID = dc.Diagnosis_Code_ID
AND dc.Diagnosis_Code not in ('V72.31', 'Z01.411', 'Z01.419')
INNER JOIN Ntier_70751.PM.Vouchers v
ON s.Voucher_ID= v.Voucher_ID
And this one will exclude patients who have at least one of the "invalid" codes (regardless of what other "valid" codes they may have):
SELECT DISTINCT
v.Patient_ID
FROM
Ntier_70751.PM.Vouchers v
WHERE
v.Patient_ID NOT IN
(
SELECT DISTINCT
v.Patient_ID
FROM
Ntier_70751.PM.Service_Diagnoses sd
INNER JOIN Ntier_70751.PM.Services s
ON sd.Service_ID = s.Service_ID
INNER JOIN Ntier_70751.PM.Diagnosis_Codes dc
ON sd.Diagnosis_Code_ID = dc.Diagnosis_Code_ID
AND dc.Diagnosis_Code in ('V72.31', 'Z01.411', 'Z01.419')
INNER JOIN Ntier_70751.PM.Vouchers v
ON s.Voucher_ID= v.Voucher_ID
)

Answer 2

Why are you attempting to do this umpteen-way join? I'm sure there's a far more efficient way to do things. We need, however, a more precise description of what you're trying to achieve.
The problem is the scope to which the restricting WHERE clause is applied. You are essentially saying
SELECT . . .
FROM (THIS
JOIN THAT
JOIN (THEOTHERONE WHERE . . .))
when what you actually need is:
SELECT . . .
FROM (THIS JOIN THAT JOIN THEOTHERONE)
WHERE . . .
By constructing the multi-way join, you are picking up and tacking on other tuples that may contain those unwanted diagnosis codes. Do your selection ("selection" means WHERE; SELECT is actually "projection" [poor choice of keywords from the creators of SQL) at the last possible moment.
Here's a suggestion. Today, you want to reject records where the diagnosis codes match, say, A, B, or C; tomorrow you may want to ALSO reject records where the diagnosis codes match P or Q. You should GENERALIZE this to make it TABLE-DRIVEN: create a second table
CREATE TABLE REJECTION_CATEGORY( CATEG, DIAGN_CODE )
PRIMARY KEY( CATEG, DIAGN_CODE )
and initialize it with the following query:
INSERT INTO REJECTION_CATEGORY VALUES( 1, 'V72.31 ),
VALUE ( 1, 'Z01.411' ),
VALUES( 1, 'Z01.419' )
then you can change your first query to:
SELECT . . .
FROM (join-of-this-and-that)
WHERE DIAGNOSIS_CODE NOT IN (
SELECT DIAGN_CODE
FROM REJECTION_CATEGORY
WHERE CATEG = 1)
and tomorrow's query, which rejects a COMPLETELY DIFFERENT set of diagnosis codes, just changes the last line but one to read WHERE CATEG = 2.