I have fours tables and I wanted to join all three tables with the one table.
I have listed my problem as follows:
Tables:
users
user_training
user_courses
user_certificates
I wanted to get the data from [2,3,4] tables that user_id field matches with the users table ID field.
When I try the INNER JOIN it gives me the result for users that are common in all the tables, But I just wanted to check the [2,3,4] tables with the table [1] Records.
My Query...
SELECT A.training_name AS 'training_name', C.course_name AS 'course_name', D.certificate_name AS 'certificate_name'
FROM user_training AS A INNER JOIN users AS B ON A.user_id=B.ID INNER JOIN user_courses AS C ON B.ID = C.user_id INNER JOIN user_certificates AS D ON B.ID = D.user_id;
Thanks in Advance.
use left join
select u.* from users u
left join user_training ut on ut.user_id=u.user_id
left join user_courses uc on uc.user_id=u.user_id
left join user_certificates uct on uct.user_id=u.user_id
With this one you are getting all users and their respective trainings:
SELECT *
FROM `users`
LEFT JOIN `user_training` ON `users`.`id` = `user_training`.`user_id`
Changing *_trainig to *_courses or *_certificates will return all users with respected courses or certificates.
If you need to get data in one query, try this one:
SELECT *
FROM `users`
LEFT JOIN `user_training` ON `users`.`id` = `user_training`.`user_id`
LEFT JOIN `user_courses` ON `users`.`id` = `user_courses`.`user_id`
LEFT JOIN `user_certificates` ON `users`.`id` = `user_certificates`.`user_id`
If user has no trainings, courses, certificates all remaining fields will be null-ed.
Related
I have to write a query such that ,I need to get events whose start date is of 30 min from now.
My conditions are:
1) get the event from events table
2)Join created by of events with id in users table.
3)Comments from comment table with user ser id
But the problem here is if there is no comment for event then the event it self is not coming.If any comment is present it is coming.I dont want this.If comment is not there just fetch it as empty but not hide the total event .Can anyone please help me,.Thanks.
select u.email ,group_members.user_id,users.first_name,u.first_name
as host_name,events.name,events.start_date,comments.comments,c.first_name as
comment_user,comments.id from events
inner join users as u on u.id = events.created_by
inner join comments on events.id = comments.event_id
inner join group_members on events.group_id = group_members.group_id
inner join users as c on comments.from_user = c.id
inner join users on group_members.user_id = users.id
where events.start_date between date_add(now(),interval 1 minute) and date_add(
now(),interval 30 minute)
and group_members.user_status = 2
and events.status = 2
You need a left join to the comments table. I would put that table last in the from clause.
select u.email, gm.user_id, gu.first_name, u.first_name as host_name,
e.name, e.start_date, c.comments, uc.first_name as comment_user,
c.id
from events e inner join
users u
on u.id = e.created_by inner join
group_members gm
on e.events.group_id = gm.group_id inner join
users gu
on gm.user_id = gu.id left join
comments c
on e.id = c.event_id left join
users uc
on c.from_user = uc.id
where e.start_date between date_add(now(),interval 1 minute) and date_add(now(),interval 30 minute) and
gm.user_status = 2 and
e.status = 2;
Once you use a left join on comments, you also need a left join for the from user. I replaced all table names with aliases -- this makes it easier to track which table is used for which purpose.
Use the INNER JOIN Keyword and select the two columns by putting them with keyword ON.
SELECT EMP.EMP_ID, EMP.EMP_NAME, DEPT.DEPT_NAME FROM EMP
INNER JOIN DEPT ON DEPT.DEPT_ID = EMP.DEPT_ID;
I am trying to get the left outer join of 2 tables with respect to two tables , but i am unable to execute this query , phpmyadmin is giving #1064 error on line 12 when running this query:
SELECT
pt.id as planid,
pt.trip_name,
pt.description,
cor.latitude,
cor.longitude,
bb.id as bookmarkid,
bb.num_of_persons as persons
FROM
planned_trips as pt,
coordinates as cor,
LEFT JOIN Bookmarkedby as bb,Users as user
ON
user.id = 1 AND
user.id = bb.user_id AND
bb.plannedtrips_id = pt.id AND
pt.coordinates_id = cor.id'
I've struggling for an hour , what am i missing??
my database schema looks like this:
I am Currently just preparing my query i need to run this query on codeIgnitor.
You need a separate LEFT JOIN for each table.
SELECT
pt.id as planid,
pt.trip_name,
pt.description,
cor.latitude,
cor.longitude,
bb.id as bookmarkid,
bb.num_of_persons as persons
FROM planned_trips as pt
INNER JOIN coordinates as cor ON pt.coordinates_id = cor.id
LEFT JOIN Bookmarkedby as bb ON bb.plannedtrips_id = pt.id
LEFT JOIN Users as user ON user.id = bb.user_id AND user.id = 1
Problem is in the line LEFT JOIN Bookmarkedby as bb,Users as user. Consider changing it to
FROM
planned_trips as pt
JOIN coordinates as cor ON pt.coordinates_id = cor.id
LEFT JOIN Bookmarkedby as bb ON bb.plannedtrips_id = pt.id
LEFT JOIN Users as user ON user.id = bb.user_id
AND user.id = 1
I have normalized tables I want to select the items that belong to the userid
I'm familiar with select syntax but I'm very weak in joins tables so I'm a bit confused on how to get the items that belong to the user should I use join ? or is there other way
this is just simple example of my tables they have more fields
..........
user
..........
userid
firstname
address
..........
items
..........
itemsid
itemName
itemDescription
..........
user_items
..........
userid(FK)
itemsid(FK)
Use two inner join
select a.*, b.*
from user_items as c
inner join user as a on a.userid = c.userid
inner join items as b on b.itemsid = c.itemsid;
Use INNER JOIN
SQL
select user.*, items.*
from user_items
inner join user on user.userid = items.userid
inner join items on items.itemsid = user_items.itemsid;
So if I read this correctly, user_items.userid = user.userid.
So you want to join, something like this.
SELECT i.itemsid, i.itemName, i.Description FROM items i JOIN users us ON ui.userid = us.userid JOIN user_items ui ON ui.itemsid = i.itemsid WHERE ui.userid = VALUE;
Replace Value with your actuall user id
This can't be too hard, but I don't know what the term is I'm looking for. I'm sure you guys can help me out. :)
I have a table tasks with rows that have a column project_id. Each project_id refers to (the id of) a row in the projects table. Each project belongs to a certain user which is why it has a column user_id.
I now want to select all tasks from this table where the project_id equals any project of a certain user.
Or put more simply:
Each TASK belongs to a PROJECT which belongs to a USER.
I want to create a SELECT-statement to receive all TASKS that belong to a specific USER. The only link between each TASK and a USER is through the PROJECT.
How do I accomplish this?
Thank you very much for your help! :)
JOIN the tables:
SELECT
t.*
FROM tasks t
INNER JOIN projects p ON t.project_id = p.project_id
INNER JOIN users u ON p.user_id = u.user_id
WHERE u.user_id = #AcertianUserId
SELECT
tasks.*
FROM
users
INNER JOIN
projects ON users.id = projects.user_id
INNER JOIN
tasks ON projects.id = tasks.project_id
WHERE
users.id = 1
SQL Fiddle
select t.*
from tasks t
join projects p on p.id = t.project_id
join users u on u.id = p.user_id
where u.id = 17
Try :
SELECT t.*
FROM user u, projet p, task t
WHERE u.id = p.user_id
AND p.id = t.project_id
AND u.id = your_id
Or (same result) :
SELECT t.*
FROM user u
INNER JOIN projet p ON u.id = p.user_id
INNER JOIN task t ON p.id = t.project_id
WHERE u.id = your_id
I have two tables. I want to draw a sample of the first table except where the person in the first table is also in a second table. Am having trouble doing this seemingly simple query.
table users
id|name
table catuser
id|userid|catid
I have tried
SELECT u.*,c.userid FROM `users` u
LEFT JOIN `catuser` c
ON (u.id = c.userid AND c.userid <> '197')
WHERE u.id = '1'
and variations to no avail. Would appreciate any suggestions.
How abt. this:
SELECT u.*,c.userid
FROM `users` u
LEFT JOIN `catuser` c
ON u.id = c.userid
WHERE u.id = '1'
AND c.userid <> '197'
AND c.userid is null
SELECT * FROM users WHERE id NOT IN (SELECT DISTINCT userid FROM catuser)
If you want to query only users that have one or more categories, you can use a WHERE EXISTS query:
SELECT u.* FROM `users` u
WHERE EXISTS (SELECT * FROM catuser WHERE catuser.userid = u.id)
Another possibility is to do a left join, and check whether the join succeeded on checking on null:
SELECT u.*, c.* FROM `users` u
LEFT JOIN catuser c ON u.id = c.userid
WHERE c.id IS NOT NULL
If there is no corresponding row in catuser, all catuser fields will be null. By checking whether c.id is not null, you only include the rows with a category.
Note that the join may return a user multiple time, if he is in multiple categories.