How to remove all the reminders belonging to the news created by Jack?
These are tables created by me with same data and now I want to fire SQL query for above requirement.
This is what I tried
DELETE FROM reminders
USING news
INNER JOIN reminders
WHERE CreatedBy = 'Jack'
AND reminders.ReminderId = news.NewsId;
I find the USING syntax in MySQL deletes to be a bit confusing -- because USING is already used syntactically as a replacement for ON.
Something like this should work:
DELETE r
FROM reminders r JOIN
news n
USING (NewsId)
WHERE n.CreatedBy = 'Jack';
Note that the join condition is on NewsId in both tables.
Related
I've created several tables in a test database based on columns/rows in my main database.
test.websites.url = main.websites.url
test.category_main = main.websites.category1
test.category_01 = main.websites.category2
test.category_02 = main.websites.category3
etc...
The test database columns already contain all the rows from the main
database, but I need to add the rows from the respective tables to the
category_to_website table and create foreign keys because there is
currently no relation between them in the test database. That is why I have joined the
main database in the query.
When trying to use the main table as a reference for updating the existing rows in the test database, some values are updated but they are not always correct. I'm executing the query from the test database.
My query:
UPDATE category_to_website
LEFT JOIN main.websites
ON websites.url = main.websites.url
LEFT JOIN category_01
ON category_01.name = main.websites.category2
SET category_to_website.category_01_id = category_01.id
WHERE category_to_website.category_01_id = main.websites.category2
My database schema:
I suspect that the issue is with the type of JOINs I am doing, but I've tried LEFT JOIN, JOIN, and INNER JOIN and get the same results. I think that maybe I need a SELECT sub query or my WHERE clause is off?
EDIT
Based on the comments I was able to get this all sorted out. Here are the steps I took.
1. Merged the category_* tables into a category table.
2. Joined the test.websites table into the query.
UPDATE test.category_to_website
LEFT JOIN test.websites
ON test.websites.id = category_to_website.url_id
RIGHT JOIN main.websites
ON test.websites.url = main.websites.url
INNER JOIN test.category
ON test.category.name = main.websites.category1
SET category_to_website.category01_id = category.id
WHERE category_to_website.url_id = test.websites.id
UPDATE category_to_website
JOIN websites
ON websites.id = category_to_website.url_id
JOIN main.websites
ON websites.url = main.websites.url
JOIN category
ON category.name = main.websites.category1
SET category_to_website.category01_id = category.id
SETs are done to rows that participate in the JOINs. But if you LEFT JOIN to category_to_website then all its rows participate so then you must restrict them in a WHERE the way you already did in the ON.
Thank goodness you have started to relationalize that horrible schema. Keep going: replace all multiple categery_ columns in each table by just one category column for id or name. And if you named them category_id and category_name their nature would be clear. (Maybe post your next version as a new question.)
SELECT submissions.created_at, guests.accepted
FROM submission
INNER JOIN guests
ON guests.event_id = 1
ORDER BY submissions.created_at ASC;
Currently this query is taking a long time to run (may not even return everything).
What I am trying to accomplish:
Grab the field submissions.created at and guests.accepted (the two are linked by a submission_id)
given a certain event_id (event 1 for example).
What is wrong with my query?
You forgot to give the JOIN condition in your query. Try this:
SELECT submissions.created_at, guests.accepted
FROM submission s
INNER JOIN guests g on g.event_id = s.submissions_id
where guests.event_id = 1
ORDER BY submissions.created_at ASC;
SELECT submissions.created_at, guests.accepted
FROM submission
INNER JOIN guests
ON guests.(column to match against) = submissions.(column to match on)
where guests.event_id=1
ORDER BY submissions.created_at ASC;
As many others here have already said, your join is a little goofed. It's attempting to join the one row that matches in the guests table against every single row in the submission column.
You would need to do your join like this :
Inner join guest on guest.event_id = submissions_id
where guest.event_id = 1
When you join you need to join on two columns from different table (most of the time id columns)
You can read the MySQL example for more explanation. And here is the link to the MySQL reference manual
I have 3 tables called
_partnership,
_partners,
_partnership_arm._partners = stores basic partner information
_partnership_arm = stores partnership arm details
_partnership = stores partners partnership records which includes the partner_id
arm_id which reference _partners.partner_id and _partnership_arm.arm_id.
So as an admin i want to select all details from the _partnership table which join other table reference without a where clause, but am having issue doing it.
here is my code
SELECT
_partnership.*,
_partners.names,
_partnership_arm.arm_name
FROM
`_partnership`
JOIN
`_partners`,`_partnership_arm` ON
_partnership.partner_id = _partners.partner_id
AND
_partnership.arm_id = _partnership_arm.arm_id
I also want a user to be able to select using a where clause
Please how can i achieve this?
Thank you.
SELECT
_partnership.*,
_partners.names,
_partnership_arm.arm_name
FROM
`_partnership`
JOIN
`_partners` ON _partnership.partner_id = _partners.partner_id
JOIN
`_partnership_arm` ON _partnership.arm_id = _partnership_arm.arm_id
I am writing a query for a health organization. The query is to pull patient data, where an encounter/appointment was completed but a chart note was not generated. I have the query pulling patients and their appointments; is there a way to basically say "only show the patients where 'master_im' document was not generated"?
I am using Microsoft SQL Server Management Studio.
Without seeing your table structures, etc. your could do a check to see if the master_im IS NULL.
SELECT *
FROM yourTable
WHERE appointment = 'completed'
AND master_im IS NULL
I would advise posting some additional details on your tables.
If the data is stored in separate tables, then you will want to JOIN the tables together to get the results you want.
EDIT #1 based on your comment you could do something like this:
select *
from person p
inner join appointments a
on p.enc_id = a.encid
left join patient_documents pd
on p.enc_id = pd.enc_id
where a.status = 'completed'
and pd.document_desc != 'master_im'
I tried looking for a question such as this on SO but a lot of them were outer joins with more complicated select clauses whereas my question is more simple and should be a faster reference for newbies at MySQL.
Being used to Oracle SQL, I was trying to join three tables and perform a delete like so:
DELETE * FROM tbl_login, tbl_profile, images
WHERE tbl_login.loginid = tbl_profile.loginid
AND tbl_profile.loginid = images.loginid
AND loginid = 'derek';
In MySQL my attempt is:
DELETE FROM tbl_profile, images, tbl_login
USING tbl_profile INNER JOIN images INNER JOIN tbl_login
WHERE tbl_profile.loginid = images.loginid
AND images.loginid = tbl_login.loginid
AND loginid='derek';
I ran this in the SQL section of PHPMyadmin and it told me that loginid was ambiguous which I thought was funny because if I'm joining the three tables why would it be ambiguous? So I edited it and made it
tbl_login.loginid = 'derek'
that deleted the correct row from the tbl_login table but it ended up deleting all the rows from my other tables. What am I doing wrong here?
Remove tbl_profile and images from your FROM clause.
I think your query should look something like this (note the different way the join conditions are defined):
DELETE FROM tbl_profile, images, tbl_login
USING tbl_profile INNER JOIN images ON images.loginid = tbl_profile.loginid
INNER JOIN tbl_login ON tbl_login.loginid = tbl_profile.loginid
WHERE tbl_login.loginid='derek';
I assume you want to delete the rows from all 3 tables. If you only want to delete from tbl_login, the previous answer tells you how to do it :)