Selecting suppliers that have at least the same approval codes as the contract requires

问题

Have a table of suppliers that have 'approval codes' (VNDAPP) and a table of contracts that have 'requirement codes' (COXA). Contracts can have any number of requirements and suppliers can have any number of approvals.

VNDAPP: (vendor approvals table)
VNUM    (vendor number)
REQMT   (approval code)

COXA:   (contract requirements table)
CONTR   (contract number)
REQMT   (requirement)

Need to find all suppliers that have approvals that, as a minimum, meet the requirements of a certain contract.

Example contract 7736 has requirements number 1 and 10. There are 27 suppliers that have both of these as a minimum. Since the requirements are variable, I cannot hard code them into the query. I'm not certain this qualifies as a relational division problem...

SELECT VNDNO
FROM VNDAPP
LEFT JOIN COXA ON VNDAPP.REQMT = COXA.REQMT
GROUP BY VNDAPP.VNDNO
HAVING Count(COXA.REQMT) = (SELECT count(*)
FROM COXA WHERE COXA.CONTR = '7736'
GROUP BY COXA.CONTR)

What am I doing wrong??

Thanks in advance!

Example data:

Contract Requirement (COXA):
CONTR   REQMT
7736    1
7736    10
7737    1
7737    4
7737    6
7738    5
7739    1



Supplier Approval (VNDAPP):
VNDNO   REQMT
10019   1
10020   1
10020   2
10020   10
10021   1
10021   4
10021   5
10021   6



Desired result:
CONTR   VNDNO
7736    10020
7737    10021
7738    10021
7739    10019
7739    10020
7739    10021

回答1:

Lets assume that you have two binding tables supplier_approval(supplierid, approvalid) and contracts_requirement(contractid, requirementid), where approvalid and requirementid corresponds. Then you can use the following query

select sa.supplierid
from supplier_approval sa
where sa.approvalid IN (
    select cr.requirementid
    from contracts_requirement cr
    where cr.contractid = 7736
 )
group by sa.supplierid
having count(distinct sa.approvalid) = (
    select count(*)
    from contracts_requirement cr
    where cr.contractid = 7736
)

回答2:

I think you just want:

SELECT VNDNO
FROM VNDAPP JOIN
     COXA
     ON VNDAPP.REQMT = COXA.REQMT
WHERE COXA.CONTR = '7736'
GROUP BY VNDAPP.VNDNO
HAVING Count(*) = (SELECT count(*)
                   FROM COXA
                   WHERE COXA.CONTR = '7736'
                  );

That is, count the requirements on the vendor that match the requirements for the contract. Then, check if the total count matches the total for the contract.

This assumes you don't have duplicate requirements on either side.

来源：https://stackoverflow.com/questions/53859081/selecting-suppliers-that-have-at-least-the-same-approval-codes-as-the-contract-r

标签

sql

db2

relational-division