I seem to be a little stumped... I'm trying to get data from three tables, but they're not all inter-related -- one table relates to each of the other two.
Exams_taken
ID
exam_id
user_id
Exams_available
ID
exam_name
Users
ID
user_name
I want to create an output where I have the exam_id, exam_name, and user_name.
I thought I could figure out how to do this as a single query, but I'm lost. Is it possible? Or do I need to do a query on 'Exams_available' and then a loop with a second query to JOIN 'Exams_taken' and 'Users'?
Thanks,
Scott
If you need an output that contains exam_id, exam_name and user_name I can suppose that you need the Exams taken, so why not just query like this:
SELECT exam_id, E.exam_name, U.user_name FROM Exams_taken as ET
INNER JOIN Exams_available as E on ET.exam_id = E.exam_id
INNER JOIN Users as U on ET.user_id = U.user_id
Related
Okay, so I have two tables, a news table and a users table. They are set up as below:
news:
id title user_id contents
users:
id username password
When I run this query:
SELECT news.title, users.username, news.contents FROM news INNER JOIN users ON news.user_id=users.id WHERE news.id=:id
I can only access the user id using $query['id']. So it appears that the join is using the column names from table2, although I want them to map it to the column names of table1. So even though the column is called id in the users table, I want to access it under user_id, since I specified that in the JOIN query.
I need this because if I ever need the id from table1, they would both be mapped to the column called id and I would only be able to get the id of the users table.
So is there any way to do this? Access the column from table2 under the name of the column in table1?
In MySQL what you specify in the select statement is what it is called in the result set, so you need to tell it what to give you. you do that with the AS command
SELECT users.id AS user_id ... FROM ...
That way you can call it whatever you want
or grab the user_id from news with
SELECT news.user_id ... FROM ...
SELECT users.id AS id1, news.id AS id2, news.title, users.username, news.contents
FROM news INNER JOIN users ON news.user_id=users.id WHERE news.id=:id
echo $query['id1'] . $query['id2'];
I have two SQL tables. The first one structure is simple.
ID Name
----------
The second one is simple too.
CommentID Comment CreatorID
----------------------------------
I want to show in my site all the comments that correspond with the "ID of user"
The problem is we have here a lot of ID and two different tables.
Something like this:
$1= $bdd->query("SELECT * FROM comments WHERE id_user=220281");
$2=$1->fetch();
But its impossible because id user is not on the comments table.
The most simple way to do this is to join the tables like this:
select
users.name,
comms.commentID,
comms.comment
from
userTable users
join commentTable comms
on users.ID=comms.ownersID
where
users.id=1
This will return the users name in each row of data, but you don't need to use it in the output more than once.
It also sounds like you could use a few pointers on SQL queries. Do yourself a favour and have a read of this article I put together a while back.
SELECT c.*
FROM comments c
INNER JOIN users u ON c.id_creator = u.id_user AND
u.id_user = 220281
A simple join will do the trick like this :
SELECT c.comment, u.user_name FROM
Users u
JOIN
Comments c ON
c.creator_id = u.user_id
WHERE
u.user_id=220281
fiddle:http://sqlfiddle.com/#!6/3b28a/1
I have two table in the same database: hlstats_Events_Connects and hlstats_PlayerUniqueIds.
In the hlstats_Events_Connects I have a value I wish to get, however the ID it's related to I need to get from the data in another table, using the "uniqueId" that I have. Example:
**hlstats_Events_Connects**
playerId eventTime
----------------------
8 2013-04-05 05:44:14
**hlstats_PlayerUniqueIds**
playerId uniqueId
---------------------
8 0:0:84901
So I have the "uniqueId" as a variable, and I want to say, get the playerId of the persons uniqueId, then get the eventTime from what the playerId is. Currently I have something along the lines of the below, but can't figure out the Where clause.
SELECT c.eventTime, c.playerId, u.uniqueId, u.playerId
FROM c.hlstats_Events_Connects, u.hlstats_PlayerUniqueIds
WHERE ...?
Cheers
Looks like you are just missing the JOIN. You will join the tables on the playerId column:
SELECT c.eventTime, c.playerId, u.uniqueId, u.playerId
FROM c.hlstats_Events_Connects c
INNER JOIN u.hlstats_PlayerUniqueIds u
ON c.playerId = u.playerId
Note, I updated the query to use ANSI JOIN syntax, in this case an INNER JOIN. This is standard SQL syntax, instead of commas between the tables and the join in the WHERE
Use JOIN like this
SELECT c.eventTime, c.playerId, u.uniqueId, u.playerId
FROM c.hlstats_Events_Connects, u.hlstats_PlayerUniqueIds
WHERE c.playerId = u.playerId
You don't need to add prefixes to table names, instead those should be specified after table name, and also you can just join on playerId column (if those are large tables, I'd suggest adding an index to those columns.)
SELECT
c.eventTime, c.playerId, u.uniqueId, u.playerId
FROM
hlstats_Events_Connects c,
hlstats_PlayerUniqueIds u
WHERE
u.uniqueId = "0:0:84901" and
u.playerId = c.playerId
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;
i have spent the last 2 days going over this problem trying to work it out.
i have two tables
one is the user_login and it has a row called user_id the other is agedcare and it has a row called id
i have tried to get the 2 to link together
i want to be able to update the agedcare using the id from user_login as the main id
$query = "SELECT id FROM agedcare INNER JOIN user_id ON login_users = login_users.user_id WHERE login_users.user_id = '$id'"
The format is something more like..
SELECT id,name,age
FROM Table1
INNER JOIN Table2
ON Table1.Field=Table2.Field
Another way to simplify the select statement (so that you avoid using the table names throughout) is to "rename" the table right after you name it. For example, the line that has "FROM Table1 T1" - the T1 immediately after the table name is "renaming" the table allowing you to shorten the table name when you need to refer to it. In addition, you can use the t1 and t2 identifiers when selecting the fields.
SELECT t1.id,t1.name,t2.age
FROM Table1 T1
INNER JOIN Table2 T2
ON T1.Field=T2.Field
Check your format of join, it must be like this
SELECT * FROM t1 as a LEFT JOIN t2 as b ON a.id=b.id where user_id = 'id'