I have the userids of people who have joined a group in one table but not their names thatlie in another table. So I think I need to do a join. I'm starting with groupid that describes the grouop.
Table 1, groupmem has groupid and userid for the members.
Table 2, users has userid and username
The users table has every user. The groupmem only has some who have joined groups.
SQL statement should be something like following but can't get it to work.
select users.name
FROM users,groupmem
LEFT JOIN users
on groupmem.userid=users.userid
WHERE groupmem.groupid = 22
22 being some value..
Thinking maybe where clause is in wrong place or I am using wrong type of join but or not using on correctly but, in any case, can't get it to work. Thx for any suggestions:
Try:
SELECT u.username
FROM `users` u
LEFT JOIN `groupmem` g
ON u.userid = g.userid
WHERE g.groupid = 22
This should do the trick:
SELECT users.name
FROM groupmem
LEFT JOIN users ON groupmem.userid = users.userid
WHERE groupmem.groupid = 22
Your query seems to be quite right - assuming I guessed your table-structure right.
Related
I currently have two tables, "tc_services" and "tc_users" which both have a "USER_ID" field and "BILLING_ID" field. I need to query these together, finding any results where...
A) "tc_services" does not have a "BILLING_ID"
B) "tc_users" does not contain a "USER_ID" that matches that of the coorelating "tc_services"
I am trying to put together a JOIN query statement such as the following but not able to figure it out so far. Any help would be appreciated!
SELECT *
FROM tc_services AS services
JOIN tc_users AS users
WHERE services.USER_ID NOT IN users.USER_ID AND services.BILLING_ID = '';
Something like:
SELECT SERVICE_ID, COUNT(users.USER_ID)
FROM tc_services AS services
LEFT JOIN tc_users AS users ON services.USER_ID = users.USER_ID
WHERE services.BILLING_ID = ''
GROUP BY services.SERVICE_ID HAVING COUNT(users.USER_ID) = 0
Second Edit after seeing your comment:
Just do
SELECT
*
FROM tc_services
WHERE tc_services.billing_id IS NULL AND
tc_services.user_id NOT IN (SELECT user_id FROM tc_users)
No joins needed
Edit:
After rereading your question, you might want an 'LEFT JOIN'
see this picture: http://i.stack.imgur.com/66zgg.png
So your query(s) would look something like
SELECT
*
FROM tc_users u
LEFT JOIN tc_services s ON a.user_id = s.user_id
WHERE s.billing_id IS NULL
which would give you the list of users that don't have a billing ID.
and then similar for the second question.
Original Answer:
Sounds like you might want to use a 'Union' rather than a 'Join'
Check out this related answer: What is the difference between JOIN and UNION?
my query looks like that:
SELECT
count(users.id)
FROM users
LEFT JOIN mail_sender_jobs_actions ON mail_sender_jobs_actions.userID = users.id
LEFT JOIN table2 ON table2.userID = users.id
LEFT JOIN table3 ON table3.userID = users.id
WHERE {$flexibleWhereClause}
Now, the mail_sender_jobs_actions table CAN (doesnt need to return anything) return multiple entries. I dont want to group the results but still limit the returns of mail_sender_jobs_actions to 1 so I dont get duplicates... Otherwise the count wouldnt work properly.
Scraped the whole web and found nothing working for me as I want to keep the where clause flexible. Any solution?
EDIT
so to explain the situation. We have a table with users (users). We have a table with actions (mail_seder_jobs_actions). We have other tables related to that query which are not relevant (table1, table2, table3)
If a user does an action, an entry is being created in the actions table.
The where clause is flexible, meaning it is possible that somebody wants to only show users with a specific action.
It is also possible that an action is not relevant to the user, so this entry gets ignored.
With where criteria you have there is no point using left join, since the where criteria applies to the table on the right hand side, effectively turning the left join into an inner join.
Apparently yo do not use any columns from the right hand side table, so instead of using joins, I would use an exists subquery.
SELECT
1 as count,
users.email
FROM users
WHERE EXISTS (SELECT 1
FROM mail_sender_jobs_actions
WHERE mail_sender_jobs_actions.userID = users.id
AND mail_sender_jobs_actions.type = '1'
AND mail_sender_jobs_actions.jobID = '106'
AND {$flexibleWhereClause})
However, there is little point in having the count() because it will always return 1. If you want to count how many records each user has in the mail_sender_jobs_actions table, then you have to use left join, group by, and move the where criteria into the join condition:
SELECT
count(mail_sender_jobs_actions.userID),
users.email
FROM users
LEFT JOIN mail_sender_jobs_actions ON mail_sender_jobs_actions.userID = users.id
AND mail_sender_jobs_actions.type = '1'
AND mail_sender_jobs_actions.jobID = '106'
AND {$flexibleWhereClause}
GROUP BY users.email
Hi I am trying to change some code so that users with certain group id do not show in search results.
at the moment the code is
$query = 'SELECT distinct b.'.$db->nameQuote('id')
.' FROM '.$db->nameQuote('#__users').' b';
I am trying to add something like the following but cannot get it to work.
select * from '.$db->quoteName('#__users').' where id not in (select user_id from #__user_usergroup_map where group_id = 8)
Any help would be appreciated.
Thanks.
This how you can try
select * from users u
where
not exists
(
select 1
from user_group ug
where
u.id = ug.iduser
AND ug.group_id = 8
)
You need change the table name and field name in the above query as your need.
DEMO
There are three ways of doing that.
Method 1: Join
Join usergroup_map table and then, select all rows that have different group_id that way:
SELECT <comma separated fields> from USERS u
LEFT JOIN USERGROUPS ug ON u.user_id = ug.user_id
WHERE ug.group_id != :group_id
GROUP BY u.user_id
And then -> bind any number to :group_id.
Please keep in mind that above statement will return users that are assigned to :group_id only if they are in another groups as well. (one to many relation).
Method 2: Subselect
Already suggested by other users.
Method 3: Join & Subselect
The 3rd, and the last option is to use sub-query within join statement, which tends to be the fastest solution in terms of optimalization. Of course, query times may be different depending on the engine you are working with, but it's worth giving a try.
SELECT <comma separated fields>
FROM USERS u
INNER JOIN (
SELECT g.user_id
FROM USERGROUPS g
WHERE g.group_id != :group_id
) ug ON ug.user_id = u.user_id
--
In this answer, I assume that you have properly configured database with foreign keys.
I am having a problem writing a MySQL query to get data from 2 tables in the same database. I don't know how to combine the 2 tables into 1 table basically so that I can use PHP to display the information. Right now I am using 2 queries and PHP to join them... I really need the persons name and the score they got.
tbl_scores
----------
user_id
points
tbl_users
---------
user_id
name
tbl_users has more fields but those are the only ones that matter I think? Please help or send what I need to look up to learn more.
SELECT * FROM tbl_scores RIGHT JOIN tbl_users ON tbl_scores.user_id = tbl_users.user_id;
The word you're looking to use is JOIN... more information on MySQL JOINs can be found all over the internet but I found one here: http://mysqljoin.com/
The following code is untested but should work for your scenario...
SELECT
u.name,
s.points
FROM
tbl_users AS u LEFT JOIN tbl_scores AS s ON u.user_id = s.user_id
use Join and more specificaly Left Join because it returns all rows from the left table (tbl_users ), even if there are no matches in the right table (tbl_scores) so that you get all users even those with no score :
SELECT * FROM tbl_users LEFT JOIN tbl_scores ON
tbl_users.user_id = tbl_scores.user_id;
My goal is that I want to get a list of user names in the database from my "users" table, but omit every user whose ID is also in the "projects_users" table where project_id = 1.
In another words, if these are the tables:
table: users
user_id user_name
1 dave
2 matt
3 james
table: projects_users
user_id project_id
1 2
2 2
3 1
This query would return "dave" and "matt" (since "james" is in the users table, but is also associated with project #1, thus he is omitted).
I understand that I should probably be using some form of join, but my current query is not doing it:
SELECT user_name
FROM users
JOIN projects_users ON (
users.user_id != (projects_users.user_id WHERE projects_users.user_id == 1)
)
This result does not work at all, and earlier experiments kept returning multiple copies of every name. Does anyone know of a way to do this without having to turn to a more manual PHP solution?
Final answer, worked perfectly. Maybe it isn't as optimised as some of the other solutions, but it's the only one that gave me valid results every time. For some reason, the other solutions sometimes popped out an unexpected name, or no name at all when they should have. Regardless, this sure beats doing it the long way with PHP.
SELECT user_id, user_name FROM users WHERE user_id NOT IN (SELECT user_id FROM projects_users WHERE project_id = 1)
Thanks everyone for your contributions. I appreciate all of your help and input.
Original answer
Utilize the power of a LEFT JOIN.
SELECT u.*
FROM users u
LEFT JOIN project_users pu ON u.user_id = pu.user_id
WHERE pu.project_id IS NULL OR pu.project_id <> 1;
Unlike JOIN (which is a shortcut for INNER JOIN), LEFT JOIN selects all rows from main table and their matching rows from joined table, BUT if the matching row is not found, a fake one is returned with all fields set to NULL.
Edit
When I re-read the question, it appeared to me that I got it wrong. If you want to filter out only users that are associated with a certain project, then this is a query to use.
SELECT DISTINCT u.user_id, u.user_name
FROM project_users pu
LEFT JOIN users u ON u.user_id = pu.user_id
WHERE pu.project_id <> 1;
try this:
SELECT DISTINCT
users.user_id,
user_name
FROM
projects_users
RIGHT JOIN
users
ON
users.user_id = projects_users.user_id
WHERE
projects_users.project_id <> 1
OR
projects_users.project_id IS NULL
Try the following:
select u.*
from users u
where exists (select null
from projects_users pu1
where u.user_id = pu1.user_id)
and not exists (select null
from projects_users pu2
where u.user_id = pu2.user_id and pu2.project_id = 1)
Alternatively:
select u.*
from users u
join projects_users pu on u.user_id = pu.user_id
group by u.user_id
having max(case when pu.project_id = 1 then 1 else 0 end) = 0