Take some of these vendor codes, they can

Based on Monster group and GPT:
Both statements express the same meaning, find the supplier code that can supply at least one of the red parts from the supplier.

However, the condition in the exists subquery in the second statement is incorrect. In the second exists subquery, instead of the PB table, the SPJB table should be used to check if there is a particular vendor offering a particular part for a particular project. Meanwhile, the equality condition(i.e. SPJB.SN=SB.SN AND SPJB.PN=PB.PN AND SPJB.JN=JN) should be used in the second exists subquery instead of the NOT EXISTS subquery.

SELECT SN
FROM SB
WHERE NOT EXISTS (
SELECT *
FROM SPJB
WHERE SPJB.SN = SB.SN AND SPJB.PN IN (
SELECT PN
FROM PB
WHERE COLOR = '红'
)
AND NOT EXISTS (
SELECT *
FROM SPJB AS SPJB2
WHERE SPJB2.SN = SB.SN AND SPJB2.PN = SPJB.PN AND SPJB2.JN = SPJB.JN
)
)