I have 2 tables in ms access 2010 as below
USERS (u_id, u_name)
LOAN (l_id, l_from[ref users.u_id], l_to[ref users.u_id], l_amount)
Users
+------+--------+
| u_id | u_name |
+------+--------+
| 1 | abc |
| 2 | def |
+------+--------+
Loan
+-----+--------+------+----------+
|l_id | l_from | l_to | l_amount |
+-----+--------+------+----------+
| 1 | 2 | 1 | 100 |
| 2 | 2 | 1 | 100 |
| 3 | 1 | 1 | 50 |
+-----+--------+------+----------+
I want to select names instead of numbers(l_from & l_to) from loan table
select
loan.l_id,
loan.l_from,
users.u_name user_from,
loan.l_to,
users.u_name as user_to,
loan.l_amount
from loan, users
where ???
JOIN the users table two times like so:
SELECT
l.l_id,
fromusers.u_name AS user_from,
tousers.u_name AS user_to,
l.l_amount
FROM loan l
INNER JOIN users fromusers ON l.l_from = fromusers.u_id
INNER JOIN users tousers ON l.l_to = tousers.u_id
SQL Fiddle Demo (it is SQL Server 2008, but should be the same syntax for ms-access, I think)
Just join on the Users table twice, once for each of from and to.
SELECT l.l_id, uFrom.u_name AS user_from,
uTo.u_name AS user_to, l.l_amount
FROM LOAN l
INNER JOIN Users uFrom ON l.l_from = uFrom.u_id
INNER JOIN Users uTo ON l.l_to = uTo.u_id
Related
I'm trying to join my users table with my jobs table based on a mapping table users_jobs:
Here is what the users table looks like:
users
|--------|------------------|
| id | name |
|--------|----------------- |
| 1 | Ozzy Osbourne |
| 2 | Lemmy Kilmister |
| 3 | Ronnie James Dio |
| 4 | Jimmy Page |
|---------------------------|
jobs table looks like this:
|--------|-----------------|
| id | title |
|--------|-----------------|
| 1 | Singer |
| 2 | Guitar Player |
|--------------------------|
And users_jobs table looks like this:
|--------|-------------|-------------|---------------|-------------|
| id | user_id | job_id | column3 | column4 |
|--------|-------------|-------------|---------------|-------------|
| 1 | 1 | 1 | 0 | 1 |
| 2 | 2 | 1 | 1 | 0 |
| 3 | 3 | 1 | 0 | 1 |
| 4 | 4 | 2 | 1 | 0 |
|----------------------|-------------|---------------|-------------|
For example, let's say the ozzy does a query.
Here is what should expect:
|--------|------------------|------------|--------- |
| id | name | column3 | column4 |
|--------|----------------- |------------|----------|
| 1 | Ozzy Osbourne | 0 | 1 |
| 2 | Lemmy Kilmister | 1 | 0 |
| 3 | Ronnie James Dio | 0 | 1 |
|---------------------------|------------|----------|
Basically, he can only see the job in which he is registered (role) and the users included.
I tried to do this:
SELECT u1.*, uj1.colum3, uj1.column4
FROM users AS u1
JOIN users_jobs AS uj1 ON uj1.user_id = 1
JOIN jobs AS j1 ON j1.id = up1.job_id
WHERE uj1.job_id = 1
Any help would be great!
Looks like you need INNER JOIN Try this :
select u.id, u.column3 , u.column4 from users u
inner join user_jobs uj on u.id=uj.user_id
inner join jobs j on j.id=uj.job_id
where uj.job_id=1;
If you need by certain user_id
select u.id, u.column3 , u.column4 from users u
inner join user_jobs uj on u.id=uj.user_id
inner join jobs j on j.id=uj.job_id
where uj.job_id=1
and u.id=1;
I found a solution.
Using #stackFan approach adding an EXISTS clause to make sure that the user is in.
SELECT u.id, u.column3 , u.column4
FROM users u
INNER JOIN user_jobs uj on u.id = uj.user_id
INNER JOIN jobs j on j.id = uj.job_id
WHERE uj.job_id = <job-ID>
AND
EXISTS (
SELECT *
FROM users_jobs AS uj
WHERE uj.job_id = <job-ID>
AND uj.user_id = <user-ID>
);
Try LEFT JOIN. It will display all users, whether they have job or not.
SELECT u.id, u.name, uj.colum3, uj.column4
FROM users AS u
LEFT JOIN users_jobs uj ON uj.user_id = u.id
LEFT JOIN jobs j ON j.id = uj.job_id
I have below table SUBJ_SKILLS which has records like
TCHR_ID | LINE_NBR | SUBJ | SUBJ_TYPE
--------| ------- | ---------- | ----------
1 | 1 | Maths | R
1 | 2 | 101 | U
2 | 1 | BehaviourialTech | U
3 | 2 | Maths | R
4 | 1 | RegionalLANG | U
5 | 3 | ForeignLANG | U
5 | 4 | Maths | R
6 | 2 | Science | R
7 | 1 | 101 | U
7 | 3 | Physics | R
..
..
I am trying to retrieve records like below (i.e. single teacher who taught multiple different subjects)
TCHR_ID | LINE_NBR | SUBJ | SUBJ_TYPE
--------| ------- | ---------- | ----------
5 | 3 | ForeignLANG | U
5 | 4 | Maths | R
7 | 1 | 101 | U
7 | 3 | Physics | R
1 | 1 | Maths | R
1 | 2 | 101 | U
Here, the line numbers are unique, means that TCHR_ID:5 taught Physics (which was LINE_NBR=1, but was removed later). So, the LINE_NBR are not updated and stay as is.
i also have a look up table (SUBJ_LKUP) for subject and their categories/type like below ('R' for Regular subject and 'U' for Unique subject )
SUBJ | SUBJ_TYPE
----------------- | ------------
Maths | R
Physics | R
ForeignLANG | U
101 | U
Science | R
BehaviourialTech | U
RegionalLANG | U
My approach to resolve this was to create a table which have 2 records for Teacher and use another query on base table (SUBJ_SKILLS) and new table to filter out distinct records. I came up with below queries..
Query-1:
create table tchr_with_2_subj as select SS.TCHR_ID
from SUBJ_SKILLS SS, SUBJ_LKUP SL
where SS.SUBJ = SL.SUBJ
and SL.SUBJ_TYPE IN ('R', 'U') AND SS.TCHR_ID IN
(select SS.TCHR_ID from SUBJ_SKILLS SS)
GROUP BY SS.TCHR_ID HAVING COUNT(*) = 2)
Query-2:
select SS.TCHR_ID from SUBJ_SKILLS SS, tchr_with_2_subj tw2s
where SS.TCHR_ID = tw2s.TCHR_ID
GROUP BY SS.TCHR_ID,SS.SUBJ_TYPE HAVING COUNT(*) > 1)
Question:
1)'IN' condition in Query-1 is causing problems and pulling wrong records.
2) Is there a better way to write query to pull matching records using a single query (i.e. instead of creating a table)
Could someone help me on this pls.
For the answer to your original question, I would use window functions:
select ss.*
from (select ss.*,
min(subj) over (partition by tchr_id) as mins,
max(subj) over (partition by tchr_id) as maxs
from SUBJ_SKILLS ss
) ss
where mins <> maxs;
It is unclear how the subject type fits in, but if you need to include that, similar logic will work.
Your second table can be obtained from your first table with:
select ss.*
from
subj_skills as ss
inner join (
select tchr_id
from subj_skills
group by tchr_id
having count(*) > 1
) as mult on mult.tchr_id=ss.tchr_id;
I'd use analytic functions here, asomething like:
select tchr_id, line_nbr, subj, SUBJ_TYPE
from (select count(distinct subj) over (partition by tchr_id) as grp_cnt,
s.*
from subj_skills s)
where grp_cnt > 1
If you need to filter out invalid records, you can do it in the inner query. If a teacher cannot teach the same subject multiple times (the req 'multiple different subjects' can be translated to 'multiple subjects'), then I'd rather use count(*) instead of count(distinct subj).
is it possible if i want to do INNER JOIN only if the record exist on the 2nd table if not then dont join?
this is my table
User table
+--------+--------------+
| id | name |
+--------+--------------+
| 1 | John |
+--------+--------------+
| 2 | Josh |
+--------+--------------+
House table
+--------+-------------+--------------+
| id | owner_id | house_no |
+--------+-------------+--------------+
| 1 | 1 | 991 |
+--------+-------------+--------------+
this is my INNER JOIN query
SELECT h.owner_id, u.name, h.house_no FROM user u
INNER JOIN house h on u.id = h.owner_id
WHERE u.id = :id
it will return this result if id = 1
+--------+--------------+--------------+
| id | name | house_no |
+--------+--------------+--------------+
| 1 | John | 991 |
+--------+--------------+--------------+
but if i run with id = 2 no result returned.
what i want to do right now is it still return the result even when no data exist for id = 2 in table house
Use a left outer join instead.
SELECT u.id, u.name, h.house_no FROM user u
LEFT OUTER JOIN house h on u.id = h.owner_id
WHERE u.id = :id
The resulting record will be:
+--------+--------------+--------------+
| id | name | house_no |
+--------+--------------+--------------+
| 2 | Josh | null |
+--------+--------------+--------------+
Trying to select the Match Table and convert the ID's into the Schools name, but right now I can only get one row to work at a time. What would my select look like instead?
select Match.ID, School, GuestTeamID from Match
inner join Team on team.id = match.HomeTeamID
Match Table
+------------+------------+-------------+
| ID | HomeTeamID | GuestTeamID |
+------------+------------+-------------+
| 1 | 1 | 2 |
| 2 | 3 | 4 |
+------------+------------+-------------+
Team Table:
+----+----------+
| ID | School |
+----+----------+
| 1 | School A |
| 2 | School B |
| 3 | School C |
| 4 | School D |
+----+----------+
Join Team table twice with Match table to fetch school name.
Try this:
SELECT M.ID, t1.School AS HomeSchool, t2.School AS GuestSchool
FROM MATCH m
INNER JOIN Team t1 ON t1.id = m.HomeTeamID
INNER JOIN Team t2 ON t2.id = m.GuestTeamID;
I have 2 tables with similar layout, involving INCOME and EXPENSES.
The id column is a customer ID.
I need a result of customer TOTAL AMOUNT, summing up income and expenses.
Table: Income
| id | amountIN|
+--------------+
| 1 | a |
| 2 | b |
| 3 | c |
| 4 | d |
Table: Expenses
| id | amountOUT|
+---------------+
| 1 | -x |
| 4 | -z |
My problem is that some customers only have expenses and others just income... so cannot know in advance id I need to do a LEFT or RIGHT JOIN.
In the example above an RIGHT JOIN could do the trick, but if the situation is inverted (more customers on the Expenses table) it doesn't work.
Expected Result
| id | TotalAmount|
+--------------+
| 1 | a - x |
| 2 | b |
| 3 | c |
| 4 | d - z |
Any help?
select id, SUM(Amount)
from
(
select id, amountin as Amount
from Income
union all
select id, amountout as Amount
from Expense
) a
group by id
I believe a full join will solve your problem.
I would approach this as a union. Do that in your subquery then sum on it.
For instance:
select id, sum(amt) from
(
select i.id, i.amountIN as amt from Income i
union all
select e.id, e.amountOUT as amt from Expenses e
)
group by id
You should really have another table like client :
Table: Client
| id |
+----+
| 1 |
| 2 |
| 3 |
| 4 |
So you could do something like that
SELECT Client.ID, COALESCE(Income.AmountIN, 0) - COALESCE(Expenses.AmountOUT, 0)
FROM Client c
LEFT JOIN Income i ON i.ID = c.ID
LEFT JOIN Expense e ON e.ID = c.ID
Will be less complicated and i'm sure it will come handy another time :)