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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);
Sample ERD Diagram
Expected Output
Example: 1, John, Doe, 1, 2022-12-31, 1, XY, Bank 1, 3B, OP.
Your WHERE 'Donor BGroup' IN (SELECT...) clause evaluates to WHERE false, because you don't have any rows with that value in tblPerson.bGroup. So, your SELECT statement's result set is empty.
It's hard to puzzle out your requirement from your question.
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:
SELECT t.adminID, person.firstName, person.lastName, t.transID, t.transDate, t.donationID, person.bGroup, b.bankName, donor.personID AS 'Donor ID', donor.bGroup AS 'Donor BGroup'
FROM tblTrans t
JOIN tblAdmin a ON t.adminID = a.adminID
JOIN tblPerson person ON a.personID = person.personID
JOIN tblDonation d ON t.donationID = d.donationID
JOIN tblPerson donor ON
JOIN tblBank b ON d.bankID = b.bankID;
Trying to collect some heirarchical data to send out to a third party, and was directed to this post.
After attempting to tweak it to my use case on SQL Fiddle, the stored procedure keeps timing out.
So I tried it on locally twice (via PhpMyAdmin).
When I try to reload PMA in the browser after calling the stored procedure, I just get an eternal "waiting for response" spinner (more than 10 or 20 minutes).
I'm presuming there's something wrong with my SP code ???
CREATE TABLE foo
(`id` int, `name` varchar(100), `parentId` int, `path` varchar(100))
//
INSERT INTO foo (`id`, `name`, `parentId`, `path`)
VALUES (1, 'discrete', 0, NULL),
(2, 'res', 1, NULL),
(3, 'smt', 2, NULL),
(4, 'cap', 1, NULL),
(5, 'ind', 1, NULL),
(6, 'smt', 4, NULL),
(7, 'tant', 6, NULL),
(8, 'cer', 6, NULL)
//
CREATE PROCEDURE updatePath()
BEGIN
DECLARE cnt, n int;
SELECT COUNT(*) INTO n FROM foo WHERE parentId = 0;
UPDATE foo a, foo b SET a.path = b.name WHERE b.parentId IS NULL AND a.parentId = b.id;
SELECT count(*) INTO cnt FROM foo WHERE path IS NULL;
while cnt > n do
UPDATE foo a, foo b SET a.path = concat(b.path, '|', b.id) WHERE b.path IS NOT NULL AND a.parentId = b.id;
SELECT count(*) INTO cnt FROM foo WHERE path IS NULL;
end while;
END//
EDIT
Expected results:
VALUES (1, 'discrete', 0, '1'),
(2, 'res', 1, '1|2'),
(3, 'smt', 2, '1|2|3'),
(4, 'cap', 1, '1|4'),
(5, 'ind', 1, '1|5'),
(6, 'smt', 4, '1|4|6'),
(7, 'tant', 6, '1|4|6|7'),
(8, 'cer', 6, '1|4|6|8');
After a good nights sleep, I took #Drew's lead and I went through it one pc at a time.
Got it working. Here's where I'm leaving it:
CREATE TABLE foo
(`id` int, `name` varchar(100), `parentId` int, `path` varchar(100))
//
INSERT INTO foo
(`id`, `name`, `parentId`, `path`)
VALUES
(1, 'dscr', 0, NULL),
(2, 'res', 1, NULL),
(3, 'smt', 2, NULL),
(4, 'cap', 1, NULL),
(5, 'ind', 1, NULL),
(6, 'chp', 4, NULL),
(7, 'tant', 6, NULL),
(8, 'cer', 6, NULL)
//
CREATE PROCEDURE updatePath()
BEGIN
DECLARE cnt, n int;
SELECT COUNT(*) INTO n FROM foo WHERE parentId = 0; -- n is now 1
SELECT COUNT(*) INTO cnt FROM foo WHERE path IS NULL; -- cnt is now 8
UPDATE foo child, foo parent -- each child now has its parent and own ID's in the path
SET child.path = CONCAT(parent.id, '|', child.id)
WHERE parent.parentId = 0
AND child.parentId = parent.id;
WHILE cnt > n DO
UPDATE foo child, foo parent -- concat parent's path and own ID into each empty child's path
SET child.path = concat( parent.path,'|',child.id )
WHERE parent.path IS NOT NULL
AND child.parentId = parent.id;
SELECT COUNT(*) INTO cnt -- decrement cnt
FROM foo
WHERE path IS NULL;
END WHILE;
UPDATE foo -- set path for any top-level categories
SET path = id
WHERE path IS NULL;
END//
call updatePath()//
Feel free to critique.
Hope this helps someone else some time.
Are you trying to do a self-referencing join to create the hierarchy?
select
a.name,
parentName = b.name
from
foo a ,
outer join foo b on
(
a.id = b.parentId
)
I am trying to build a product review page where users can comment any submitted reviews like Amazon. I want the page to display 3 user reviews as well as 2 responses to each of the reviews if they exist.
Here's the table
CREATE TABLE product_review
(`ID` int, `username` varchar(21), `review_title` varchar(30), `review_or_reply` int)
;
INSERT INTO product_review
(`ID`, `username`, `review_title`, `review_or_reply`)
VALUES
(1, 'Tom', 'Rip-off', 0),
(2, 'Peter', 'Rip-off', 1),
(3, 'May', 'Rip-off', 1),
(4, 'June', 'Rip-off', 1),
(5, 'Tommy', 'Worth the Price', 0),
(6, 'Sammy', 'Worth the Price', 1),
(7, 'Sam', 'Worth the Price',1),
(8, 'Bryan','Worth the Price',1),
(9, 'Sally', 'Average Product', 0)
;
The review_or_reply field is effectively a Yes or No field, where 0 means it's a review and 1 is the review's comments by other users.
Is there a single select statement that can limit 3 reviews and bring up two of their comments? For example:
Select `username`,`review_title`,`reply` from product_review where review_or_reply ='0' Limit 3
Select `username`,`review_title`,`reply` from product_review where review_or_reply = '1' and title = 'Rip-off' Limit 2
Select `username`,`review_title`,`reply` from product_review where review_or_reply = '1' and title = 'Worth the Price' Limit 2
Select `username`,`review_title`,`reply` from product_review where review_or_reply = '1' and title = 'Average Product' Limit 2
I want the output to be like this:
username review_title review_or_reply
Tom Rip-off 0
Peter Rip-off 1
May Rip-off 1
Tommy Worth the Price 0
Sammy Worth the Price 1
Sam Worth the Price 1
Sally Average Product 0
this will return 3 review_titles and then pull out two responses to that
SELECT
pr.*,
IF( #A = t.review_title,
IF(#B = 3, #B := 1, #B := #B +1)
, #B
) AS group_col,
#A := t.review_title
FROM (
SELECT
id,
username,
review_title
FROM product_review
WHERE reply ='0' LIMIT 3
) t
JOIN product_review pr ON pr.review_title=t.review_title
CROSS JOIN (SELECT #A := "", #B := 1) AS temp
GROUP BY group_col, review_title
ORDER BY id;
EDIT:
if there are more than one reply that is 0 in the database like so then this query will check for that. (since you did specify in the other queries that the reply had to be 1).
INSERT INTO product_review
(`ID`, `username`, `review_title`, `reply`)
VALUES
(1, 'Tom', 'Rip-off', 0),
(2, 'Peter', 'Rip-off', 1),
(3, 'May', 'Rip-off', 0),
(4, 'June', 'Rip-off', 1),
(5, 'Tommy', 'Worth the Price', 0),
(6, 'Sammy', 'Worth the Price', 1),
(7, 'Sam', 'Worth the Price',1),
(8, 'Bryan','Worth the Price',1),
(9, 'Sally', 'Average Product', 0),
(10, 'Timothy', 'Rip-off', 1)
notice that at id 3 there is a reply of 0 with id 10 a reply of 1. this query will correctly skip the reply = 0.
SELECT
pr.*,
IF( #A = t.review_title,
IF(pr.reply = 0, 1,
IF(#B = 3, #B := 1, #B := #B +1)
), #B
) AS group_col,
#A := t.review_title
FROM (
SELECT
DISTINCT
id,
username,
review_title
FROM product_review
WHERE reply ='0'
GROUP BY review_title
LIMIT 3
) t
JOIN product_review pr ON pr.review_title=t.review_title
CROSS JOIN (SELECT #A := "", #B := 1) AS temp
GROUP BY group_col, review_title
ORDER BY id;
DEMO
...or slower but simpler...
SELECT x.*
FROM product_review x
JOIN product_review y
ON y.review_title = x.review_title
AND y.id <= x.id
GROUP
BY x.id
HAVING COUNT(*) <= 3
ORDER
BY MIN(y.id)
LIMIT 3;
I have the following table structure. The idea is that users have permissions to a forum either by their class or specific user overrides. ('action' in both cases is an enum with values 'read' & 'write')
user (id, class)
forum (id, name)
forum_permissions (forum_id, class_id, action)
forum_user_permissions (forum_id, user_id, action)
With the following query, I'm getting extra results based on rows in forum_permissions that I don't expect. By this I mean that every row on forum_permissions with forum_id = 3 is returned even though the class_id does not match.
SELECT forum.id AS forum_id, forum.name
FROM forum
JOIN forum_permissions ON forum_permissions.forum_id = forum.id
LEFT JOIN forum_user_permissions ON (
forum_user_permissions.forum_id = forum.id AND forum_user_permissions.user_id = 3 )
WHERE (( forum_permissions.class_id = 1 AND forum_permissions.action = 'read' )
OR
( forum_user_permissions.action = 'read' ))
e.g. I get this:
FORUM_ID NAME
1 chat
2 support
3 secret
3 secret
3 secret
3 secret
but expected this:
FORUM_ID NAME
1 chat
2 support
3 secret
I have made an SQL Fiddle with the specific example including data http://sqlfiddle.com/#!2/75c3a/5/0
Your left join is adding those extra lines. mybe if you change the WHERE
WHERE forum_user_permissions.user_id is not null and (
(forum_permissions.class_id = 1 AND forum_permissions.action = 'read')
OR
(forum_user_permissions.action = 'read')
)
Or
SELECT
forum.id AS forum_id, forum.name
FROM
forum
JOIN
forum_permissions
ON
forum_permissions.forum_id = forum.id
LEFT JOIN
forum_user_permissions
ON (
forum_user_permissions.forum_id = forum.id
)
WHERE forum_user_permissions.user_id = 3 and (
(forum_permissions.class_id = 1 AND forum_permissions.action = 'read')
OR
(forum_user_permissions.action = 'read')
)
But it depends on the results your are trying to get
Okay, I solved it myself by using LEFT JOIN's for both permission tables, rather than put the logic in a WHERE clause. I'm not very sure if this is a better approach than my first attempt and will gladly upvote if someone can explain.
SELECT forum.id AS forum_id, forum.name
FROM forum
LEFT JOIN forum_permissions
ON ( forum_permissions.forum_id = forum.id
AND forum_permissions.class_id = 1
AND forum_permissions.action = 'read' )
LEFT JOIN forum_user_permissions
ON ( forum_user_permissions.forum_id = forum.id
AND forum_user_permissions.user_id = 3
AND forum_user_permissions.action = 'read' )
WHERE forum_permissions.forum_id IS NOT null OR forum_user_permissions.forum_id IS NOT null
The full dataset is included below as I guess the fiddle will expire at some point.
INSERT INTO user
(`id`, `class`)
VALUES
(1, 1), (2, 1), (3, 1), (4, 2);
INSERT INTO forum
(`id`, `name`)
VALUES
(1, 'chat'), (2, 'support'), (3, 'secret');
INSERT INTO forum_permissions
(`forum_id`, `class_id`, `action`)
VALUES
(1, 1, 'read'), (1, 1, 'write'),
(1, 2, 'read'), (1, 2, 'write'),
(2, 1, 'read'), (2, 1, 'write'),
(2, 2, 'read'), (2, 2, 'write'),
(3, 2, 'read'), (3, 2, 'write'),
(3, 3, 'read'), (3, 3, 'write');
INSERT INTO forum_user_permissions
(`forum_id`, `user_id`, `action`)
VALUES
(3, 3, 'read'), (3, 3, 'write');
I have a database of students.
CREATE TABLE classlist
(`id` int, `studentid` int, `subjectid` int, `presentid` int)
;
CREATE TABLE student
(`id` int, `name` varchar(4))
;
CREATE TABLE subject
(`id` int, `name` varchar(4))
;
CREATE TABLE classStatus
(`id` int, `name` varchar(8))
;
INSERT INTO classlist
(`id`, `studentid`, `subjectid`, `presentid`)
VALUES
(1, 111, 1, 1),
(2, 222, 3, 0),
(3, 333, 2, 1),
(4, 111, 4, 1),
(5, 111, 1, 0),
(6, 222, 3, 0),
(7, 333, 2, 1),
(8, 111, 4, 1),
(9, 111, 2, 0),
(10, 111, 4, 1),
(11, 111, 1, 1),
(12, 333, 3, 1),
(13, 333, 2, 1),
(14, 333, 3, 1)
;
INSERT INTO student
(`id`, `name`)
VALUES
(111, 'John'),
(222, 'Kate'),
(333, 'Matt')
;
INSERT INTO subject
(`id`, `name`)
VALUES
(1, 'MATH'),
(2, 'ENG'),
(3, 'SCI'),
(4, 'GEO')
;
INSERT INTO classStatus
(`id`, `name`)
VALUES
(0, 'Absent'),
(1, 'Present')
;
And I have a query which shows how many times they have been present or absent.
SELECT
studentid,
students.name AS NAME,
SUM(presentid = 1) AS present,
SUM(presentid = 0) AS absent
FROM classlist
INNER JOIN student as students ON classlist.studentid=students.id
GROUP BY studentid, NAME
See this fiddle below.
http://sqlfiddle.com/#!2/fe0b0/1
There seems to be a trend from looking at this sample data that after someone attends subjectid 4 they are often not coming to the next class. How can I capture this in a query. I want to ONLY show data WHERE last subjectid =4. So in my sample data rows matching my criteria would be.
(5, 111, 1, 0),
(9, 111, 2, 0),
(11, 111, 1, 1),
as these rows are all the next row of a studentid who had a subjectid=4.
My output would be
| STUDENTID | NAME | PRESENT | ABSENT|
| 111 | John | 1 | 2 |
To get the next class for a student, use a correlated subquery:
select cl.*,
(select min(cl2.id) from classlist cl2 where cl2.studentid = cl.studentid and cl2.id > cl.id) as nextcl
from classlist cl
Plugging this into your query example tell you you who is present and absent for the next class:
SELECT students.id, students.name AS NAME,
SUM(cl.presentid = 1) AS present, SUM(cl.presentid = 0) AS absent,
sum(clnext.presentid = 1) as presentnext
FROM (select cl.*,
(select min(cl2.id) from classlist cl2 where cl2.studentid = cl.studentid and cl2.id > cl.id) as nextcl
from classlist cl
) cl INNER JOIN
student as students
ON cl.studentid = students.id left outer join
classlist clnext
on cl.nextcl = clnext.id
GROUP BY students.id, students.NAME
Add a where cl.subjectid = 4 to get the answer for subject 4.
I fixed the query. The SQLFiddle is k.
A quick and dirty solution could be to get the Classlist.Id for all lines where subjectid=4 (let's call them n) then select all the lines where Id = n+1