i have table of members
table members :
pid| id | name
1 | id01 | jenny
2 | id02 | kain
3 | id03 | alex
and have another table members_opt
table members_opt
pid | members_id | category
1 | id01 | cat
2 | id01 | dog
3 | id02 | dog
4 | id03 | NULL
now i use below SQL query
SELECT * FROM members a JOIN
(SELECT members_id, max(category) as category FROM members_opt GROUP BY members_id) b
ON a.id = b.members_id
But this SQL Query not catch "id03"'s data because "id03"'s members_opt.category is NULL
I want this result
result :
id | name | category
id01 | jenny | cat
id02 | kain | dog
id03 | alex | NULL
(the result now showed double name, double id value.)
How can i use SQL query?
You can try this -
SELECT * FROM members a JOIN
(SELECT members_id, max(CASE WHEN category IS NULL THEN 0) as category FROM members_opt GROUP BY members_id) b
ON a.id = b.members_id
Use the below query to get your desired output -
SELECT a.id, a.name, b.category FROM members a INNER JOIN
(SELECT members_id, category FROM members_opt GROUP BY members_id) b
ON a.id = b.members_id
Just change JOIN to LEFT JOIN :
SELECT a.id, a.name, b.category
FROM members a
LEFT JOIN (
SELECT members_id, max(category) as category
FROM members_opt GROUP BY members_id) b
ON a.id = b.members_id
and if you want 'cat' for 'jenny', you should use aggregation function min.
Related
Looking to join 3 tables, but having trouble on the last one.
members
ID | name
---------
1 | John
2 | Jane
3 | Jack
member_points (can have multiple transactions between members)
ID | date | id_from | id_to
---------------------------
1 | 8/8 | 1 | 2
2 | 8/8 | 1 | 2
3 | 8/8 | 3 | 2
member_ratings (one member can only rate another member, one time)
ID | id_from | id_to | rating
-----------------------------
1 | 2 | 1 | 5
Each member may rate each member only once, and can only rate the member they received a point from, based on the member_points table.
My current query achieves this, however I'm having difficulty introducing the 3rd table, that will include the rating accoringly.
Here is what I have so far:
$sql = '
SELECT *,
m.id AS id,
c1.id AS id_from,
c1.name AS name_from,
c2.id AS id_to,
c2.name AS name_to
FROM member_points AS m
JOIN members AS c1 ON m.id_from = c1.id
JOIN members AS c2 ON m.id_to = c2.id
and m.id_to='.$_SESSION["userid"].'
GROUP BY name_from';
My goal is join the 3rd table so I can call the associated rating.
ID | name_from | name_to | rating
----------------------------------
1 | 2 | 1 | 5
2 | 2 | 3 | pending
#Andrew you need to use a LEFT JOIN to join in the member_ratings table like this:
$sql = '
SELECT *,
m.id AS id,
c1.id AS id_from,
c1.name AS name_from,
c2.id AS id_to,
c2.name AS name_to,
IF(mr.rating IS NULL, 'pending', mr.rating) AS rating
FROM member_points AS m
JOIN members AS c1 ON m.id_from = c1.id
JOIN members AS c2 ON m.id_to = c2.id
and m.id_to='.$_SESSION["userid"].'
LEFT JOIN member_ratings AS mr ON mr.id_from = c1.id
AND mr.id_to = c2.id
GROUP BY name_from';
please let me know if this isn't what you need and I'll try to help you further.
How do I build a joint to select either table
Table jobs
Id | name | salary | company | type
1 | php | 17.850 | 5 | 1
2 | mysql | 4.500 | 89 | 2
2 | nodejs | 7.500 | 89 | 1
Table Company
Id | name | Area | status
1 | Facebook| Developer| 1
2 | Google | Manager | 1
Table Candidate
Id | name | City | phone
1 | Alan Kout | Nevada | 1 555 6666
2 | Wagner Mom | L.A. | 1 444 8965
My query mysql, inner join candidate or company
If type == 1 in table jobs INNER JOIN ON table company
If type == 2 in table jobs INNER JOIN ON table candidate
Example
SELECT * FROM table_jobs
IF(table_jobs.type == 1, INNER JOIN table_company, INNER JOIN table_candidate)
This is possible?
You can achieve this using a LEFT JOIN instead of an INNER JOIN:
SELECT *
FROM table_jobs tj
LEFT JOIN table_company tco ON tj.type = 1 AND tco.id = tj.id
LEFT JOIN table_candidate tca ON tj.type = 2 AND tca.id = tj.id
This will join to table_company where the type is 1, and table_candidate where the type is 2.
You can then SELECT whichever columns are needed from each table as appropriate.
Use left join and coalesce():
SELECT tj.*,
coalesce(co.name, ca.name) as name,
. . .
FROM table_jobs tj LEFT JOIN
table_company co
ON co.id = tj.id and tj.type = 1 LEFT JOIN
table_candidate ca
ON ca.id = tj.id and tj.type = 2;
If you want both joins in one result you can use the UNION operator
SELECT *
FROM table_jobs INNER JOIN table_company
WHERE table_jobs.type=1
UNION
SELECT *
FROM table_jobs INNER JOIN table_candidate
WHERE table_jobs.type=2
I have tables books and bookType which pose a 1 X n relationship.
books
+-----+------------------+----------+-------+
| id | title | bookType | price |
+-----+------------------+----------+-------+
| 1 | Wizard of Oz | 3 | 14 |
| 2 | Huckleberry Finn | 1 | 16 |
| 3 | Harry Potter | 2 | 25 |
| 4 | Moby Dick | 2 | 11 |
+-----+------------------+----------+-------+
bookTypes
+-----+----------+
| id | name |
+-----+----------+
| 1 | Fiction |
| 2 | Drama |
| 3 | Children |
+-----+----------+
How would I retrieve bookTypes where all books are more expensive than e.g. 12($)?
In this case, the expected output would be:
+-----+----------+
| id | name |
+-----+----------+
| 1 | Fiction |
| 3 | Children |
+-----+----------+
You can use not exists:
select t.*
from bookTypes t
where not exists (
select 1
from books b
where b.bookType = t.id and b.price < 12
)
If you want to select book types that also have at least one associated book:
select t.*
from bookTypes t
where
exists (select 1 from books b where b.bookType = t.id)
and not exists (select 1 from books b where b.bookType = t.id and b.price < 12)
Do a GROUP BY, use HAVING to return only booktypes having the lowest price > 12.
SELECT bt.name
FROM bookTypes bt
INNER JOIN books b ON b.bookType = bt.id
group by bt.name
HAVING SUM(b.price <= 12) = 0;
You can directly consider using having min(price) >= 12 with grouping by bookType
select t.id, t.name
from bookTypes t
join books b
on t.id = b.bookType
group by b.bookType
having min(price) >= 12
Moreover, if your DB's version is at least 10.2, then you can also use some window functions for analytical queries such as min(..) over (partition by .. order by ..) :
with t as
(
select t.id, t.name, min(price) over (partition by bookType) as price
from bookTypes t
join books b
on t.id = b.bookType
)
select id, name
from t
where price >= 12
in which min() over (..) window function determines minimum price for each booktype by use of partition by bookType
Demo
I think GMB's solution is likely the best so far. But for sake of completeness: You can also use the ALL operator with a correlated subquery. That's probably the most straight forward solution.
SELECT *
FROM booktypes bt
WHERE 12 < ALL (SELECT b.price
FROM books b
WHERE b.booktype = bt.id);
Can you not just select from books inner join bookTypes on id WHERE price > 12?
SELECT bt.*
FROM bookTypes bt
INNER JOIN books b ON b.bookType = bt.id
WHERE b.price > 12
I am trying to write a MySQL query to select all rows from table a, as well as information from table b, while also querying the count and sum of values in another table c, for each row of a.
I will try to break that down a bit better, here is a simplified version of my tables:
Table A
+---------+----------+-----------+
| id | name | bid |
+---------+----------+-----------+
| 1 | abc | 1 |
| 2 | def | 1 |
| 3 | ghi | 2 |
+--------------------------------+
Table B
+---------+----------+
| id | name |
+---------+----------+
| 1 | STAN |
| 2 | UCLA |
+--------------------+
Table C
+---------+----------+-----------+
| id | aid | cnumber |
+---------+----------+-----------+
| 1 | 1 | 40 |
| 2 | 1 | 20 |
| 3 | 2 | 10 |
| 4 | 3 | 40 |
| 5 | 3 | 20 |
| 6 | 3 | 10 |
+--------------------------------+
What I need is a query that will return rows containing
a.id | a.name | b.id | b.name | SUM(c.cnumber) | COUNT(c.cnumber)
I am not sure if such a thing is even possible in MySQL.
My current solution is trying to query A + B Left Join and then UNION with A + C Right Join. It's not giving me the results I'm looking for however.
Thanks.
edit:
current query re-written for this problem:
SELECT
a.id,
a.name,
b.id,
b.name
"somecolumn" as dummy_column
"somecolumn1" as dummy_column1
FROM a
LEFT OUTER JOIN b ON a.b.id = b.id
UNION
SELECT
"somecolumn" as dummy_column
"somecolumn1" as dummy_column1
"somecolumn2" as dummy_column2
"somecolumn3" as dummy_column3
COUNT(c.cnumber) AS ccount
SUM(c.cnumber) AS sum
FROM a
RIGHT OUTER JOIN c ON a.id = c.a.id;
Unfortunately MySQL doesn't have FULL OUTER JOIN, and this is my temporary work around, although I don't think it's even the proper idea.
My desired output is all the rows from table A with some info from table B, as well as their totaled inputs in table C.
edit2:
SELECT
a.id,
a.name,
b.id,
SUM(c.cnumber) as totalSum,
(SELECT count(*) FROM c as cc WHERE cc.aid = a.id) as totalCount
FROM
a
LEFT JOIN b ON a.bid = b.id
LEFT JOIN c ON c.aid = a.id;
For future similar questions, solution:
SELECT
a.id AS aid,
a.name,
b.id,
(SELECT SUM(c.rating) FROM c WHERE c.aid = aid) AS totalSum,
(SELECT COUNT(c.rating) FROM c WHERE c.aid = aid) AS totalCount
FROM
a
LEFT JOIN b ON a.bid = b.id;
Your query should be :-
SELECT
a.id,
a.name,
b.id,
(SELECT SUM(c.cnumber) FROM c as cd WHERE cd.aid = a.id) as totalSum,
(SELECT count(*) FROM c as cc WHERE cc.aid = a.id) as totalCount
FROM
a
LEFT JOIN b ON a.bid = b.id
LEFT JOIN c ON c.aid = a.id;
It may help you.
I have tried your example.
SELECT * ,
(SELECT SUM(cnumber) FROM `table_c` WHERE `table_c`.`iaid` = `table_a`.`id`),
(SELECT COUNT(cnumber) FROM `table_c` WHERE `table_c`.`a.id` = `table_a`.`id`)
FROM `table_a`,`table_b` WHERE `table_b`.`id` = `table_a`.`b.id`
i got the Following output.
I am trying to sum some columns from multiple tables in just one SQL query, but I seem to be getting the wrong results. I think there is a problem with the code that I have provided below. Please any help on this is appreciated.
item Names
| id | name |
| 1 | AB |
| 2 | CA |
table1
| id | interest | year |
| 1 | 20.00 | 2014 |
| 2 | 30.00 | 2013 |
| 1 | 10.00 | 2013 |
table2
| id | deposit | year |
| 1 | 10.00 | 2014 |
| 2 | 10.00 | 2014 |
This is the query that I tried:
SELECT
a.name,
b.year,
sum(b.interest) as 'total'
FROM
`table1` b
INNER JOIN
`item names` a
ON
b.id=a.id
GROUP BY
b.id
UNION ALL
SELECT
c.name,
d.year,
sum(d.deposit) as 'total'
FROM
`table2` d
INNER JOIN
`item names` c
ON
d.id=c.id
GROUP BY
d.id
EXPECTED RESULTS
UPDATE
I am trying to find the total sum of interest and deposit for a particular year and for a particular item
|name | year | total |
| AB | 2014 | 30.00 |
| AB | 2013 | 10.00 |
| CA | 2013 | 30.00 |
| CA | 2014 | 10.00 |
Perhaps... assuming table1 and table2 have same structure.
First I generate a set with the union values from one and two then we use a simple aggregate and a group by to sum the values by name and year.
SELECT I.Name, B.year, Sum(B.Total)
FROM item I
INNER JOIN
(SELECT * FROM table1 UNION select * FROM table2) B
on B.ID = I.ID
GROUP BY I.Name, B.Year
In the query you have posted, you need to group by year also to get the results. Then, you can use UNION to get all of the rows from the first set, along with all of the rows from the second set:
SELECT a.name, b.year, SUM(b.interest) AS total
FROM names a
JOIN table1 b ON b.id = a.id
GROUP BY a.name, b.year
UNION
SELECT a.name, c.year, SUM(c.deposit) AS total
FROM names a
JOIN table2 c ON c.id = a.id
GROUP BY a.name, c.year;
However, this doesn't give you your final results, as names that appear in each table ('AB' for example) will appear twice. One row for the year in deposits, one row for the year in interests. To combine those, just use the above as a subquery, sum the totals and again group by name and date:
SELECT name, year, SUM(total) AS total
FROM(
SELECT a.name, b.year, SUM(b.interest) AS total
FROM names a
JOIN table1 b ON b.id = a.id
GROUP BY a.name, b.year
UNION
SELECT a.name, c.year, SUM(c.deposit) AS total
FROM names a
JOIN table2 c ON c.id = a.id
GROUP BY a.name, c.year) temp
GROUP BY name, year;
Here is an SQL Fiddle example.