I have created an entity tblPerson and from this entity I need to get the bGroup of t.adminID and the bGroup from the d.personID. I have tried the below query but it’s not returning anything.
`
SELECT t.adminID, p.firstName, p.lastName, t.transID, t.transDate, t.donationID, p.bGroup, b.bankName, d.personID AS 'Donor ID', 'Donor BGroup'
FROM tblTrans t
JOIN tblAdmin a ON t.adminID = a.adminID
JOIN tblPerson p ON a.personID = p.personID
JOIN tblDonation d ON t.donationID = d.donationID
JOIN tblBank b ON d.bankID = b.bankID
WHERE 'Donor BGroup' IN
(SELECT p.bGroup
FROM tblPerson p
JOIN tblDonation d ON p.personID = d.personID
JOIN tblTrans t ON d.donationID = t.donationID);
`
When I execute the subquery, it gives me the bGroup of the d.personID, what do you think is going on, and maybe any alternatives, please?
Sample Data
INSERT INTO tblPerson (personID, firstName, lastName, bGroup)
VALUES ('1A', 'John', 'Doe', 'XY'),
('2A', 'Joe', 'Bishop', 'AB'),
('1B', 'Elly', 'James', 'OP'),
('2B', 'Andre', 'Butch', 'XY'),
('3A', 'Amy', 'Gree', 'AB'),
('3B', 'Alfred', 'Black', 'OP'),
('4C', 'James', 'Brown', 'XY');
INSERT INTO tblAdmin (adminID, personID, description)
VALUES (1, '1A', 'Whatever.'),
(2, '1B', ''),
(3, '4C', 'Anything.'),
(4, '1A', '');
INSERT INTO tblDonation (donationID, bankID, personID, donationDate)
VALUES (1, 1, '3B', '2018-12-27'),
(2, 1, '2A', '2022-12-28'),
(3, 2, '3A', '2022-03-23'),
(4, 2, '4C', '2022-06-19'),
(5, 3, '1B', '2022-08-19'),
(6, 3, '2B', '2022-08-08'),
(7, 3, '3B', '2022-07-20'),
(8, 2, '4C', '2022-11-26'),
(9, 1, '3B', '2022-11-26'),
(10, 2, '2A', '2022-01-16');
INSERT INTO tblBank (bankID, bankName)
VALUES (1, 'Bank 1'),
(2, 'Bank 2'),
(3, 'Bank 3');
INSERT INTO tblTrans (transID, transDate, donationID, adminID)
VALUES (1, '2022-12-31', 1, 1),
(2, '2022-01-01', 2, 1),
(3, '2022-05-23', 3, 2),
(4, '2022-05-23', 4, 2),
(5, '2022-07-09', 5, 3),
(6, '2022-08-20', 6 4),
(7, '2022-12-27', 7,4);
Expected Output
Example: 1, John, Doe, 1, 2022-12-31, 1, XY, Bank 1, 3B, OP.
2
Answers
I managed to find the solution. Since I needed to call the same table twice with different IDs I had to create two aliases and JOIN the table twice, like so:
Your
WHERE 'Donor BGroup' IN (SELECT...)
clause evaluates toWHERE false
, because you don’t have any rows with that value intblPerson.bGroup
. So, your SELECT statement’s result set is empty.It’s hard to puzzle out your requirement from your question.