Joining 2 tables in PHP - php

This might be a dumb and very simple question, but I'm stuck and I've tried multiple ways already. So I have this code:
$RefLinksRAW = $GLOBALS['DATABASE']->query("
SELECT u.id, u.username FROM ".USERS." as u
LEFT JOIN ".TURNAMENT." as s
ON s.id_owner = u.id;");
But I want to also SELECT columns from TURNAMENT that corresponds to s.id_owner, how do I do that?
Basically I want to make a table that shows contents from both of those tables.
This is the TURNAMENT table, I want to make sure that 'id' from USERS table is same as 'id_owner' and also select 'wons' column

You can just add the columns you are after to the SELECT section. For example,
SELECT
u.id,
u.username,
s.somecolumn,
s.someothercolumn
FROM
users u
LEFT JOIN
turnament s ON s.id_owner = u.id;
Replace users and turnament with your actual table names, and somecolumn/someothercolumn with the columns you are after.

Related

join of two sql tables

I have two tables and I want to join them to get the desired output.
Say the 1st table (seat1) is
and the 2nd table (collegestudents) is
The desired output is
I have tried the below code. But it fails to give the desired result.
$rde2=mysqli_query($con, "select * from seat1 s
left JOIN collegestudents c ON c.Roll = s.Roll
");
Any help please.
You want a left join. Your query looks fine, but you would need not to use select *, and instead explictly list the columns that you want to select, using table prefixes. Otherwise, since you have a Roll column in both tables, a name clashes will happen, that your application apparently does not handle well.
select
s.Roll,
c.Name,
s.Subject
from seat1 s
left join collegestudents c on c.Roll = s.Roll

How to join 2 values from different tables in mysql

I'm a beginner in MySQL, so I need help.
I want to get values of name column from table role to show it together with information from users instead id_role.
How can I realize it? What should the query I write?
Can you attach the link with solve?
The picture for explanation.
Read more here about SQL JOINS
SELECT users.*, role.*
FROM users
INNER JOIN role ON users.id_role = role.id;
Try LEFT JOIN
SELECT `users`.*,`role`.name as role FROM `users` LEFT JOIN `role` ON `users`.id_role= `role`.id

How to join all three tables in MYSQL?

I have a MySQL database that has three tables holding information about uploaded photos by users. I have a PHP page that displays all the photos in the database (tbl_uploads) and who uploaded them (tbl_users). To display the photos and who uploaded them I have a join in the MySQL query.
SELECT *
FROM tbl_uploads, tbl_users
WHERE tbl_uploads.user_id = tbl_users.user_id
ORDER BY date DESC
I now want to join a third table tbl_collab to the MySQL query that allows me to display all the users that collaborated with the photo (a form allows them to post the $file and their $user_id to tbl_collab). I guess I need to add a join from tbl_uploads.file with tbl_collab.user_id but I'm not sure how.
tbl_users
|//**user_id**//|int(11)|No|
|user_name|varchar(25)|No|
|user_email|varchar(60)|No|
|user_password|varchar(255)|No|
|joining_date|datetime|No|
tbl_uploads
|//**id**//|int(10)|No|
|file|varchar(100)|No|
|type|varchar(30)|No|
|size|int(11)|No|
|user_id|int(11)|No|
|user_name|varchar(25)|No|
tbl_collab
|//**id**//|int(11)|No|
|user_name|varchar(100)|No|
|user_id|int(11)|No|
|file|varchar(255)|No|
I have been trying your various suggestions and I can't really get them to work as I would hope so I have made a mysql fiddle that might be help me.
The problem is that when I loop through the rows that the query throws up in PHP I ether get just the rows where there is join with tbl_uploads.file and tbl.collab.file or I get the multiple rows duplicating themselves.
I'd suggest preferring ANSI SQL syntax for joins (over mentioning multiple tables in the "from" clause) as once the queries get complex I find the ANSI syntax easier to follow. Using that syntax, joining multiple tables is no big deal. e.g.,
SELECT uploads.<column>, users.<column>, collabs.<column>
FROM tbl_uploads uploads
JOIN tbl_users users ON users.user_id=uploads.user_id
JOIN tbl_collabs collabs ON collabs.file=uploads.file
ORDER BY uploads.date DESC
(Note, replace <column> above with the names of columns you want to select from the respective tables, using AS syntax to provide unique names where necessary.)
Consider that you will probably want to create indexes over the fields in the join conditions for performance if you expect the database will become large. You may also want to use left joins when joining, e.g., tbl_collabs if it is possible an upload will have no collaborators, otherwise the query will return no data if there are no matching rows in tbl_collabs.
The first thing to do is to normalize your data. If you look closely, username appears in all three tables. It shouldn't. It belongs only in the users table. Then your other tables need to have a user_id field instead of the username.
tbl_uploads
|//**id**//|int(10)|No|
|file|varchar(100)|No|
|type|varchar(30)|No|
|size|int(11)|No|
|user_id|int(11)|No|
tbl_collab
|//**id**//|int(11)|No|
|user_id|int(11)|No|
|file|varchar(255)|No|
In both cases the user_id is a foreign key to the id field in the users table. Now we have something consistent to join on.
SELECT * FROM tbl_uploads
INNER JOIN tbl_users ON tbl_uploads.user_id = tbl_users.user_id
INNER JOIN tbl_collab ON tbl_collab.file = tbl_uploads.file
Whether you should use INNER JOIN or LEFT JOIN depends on exactly what you need to do with your data, but INNER JOIN seems more appropriate based on information provided.
Update: As #drew pointed out, none of your tables have a column named date did you perhaps intend to sort by tbl_users.joining_date?
Seems the join is on file to me
SELECT *
FROM tbl_uploads
inner join tbl_users on tbl_uploads.user_id = tbl_users.user_id
inner join tbl_collab on tbl_collab.file = tbl_uploads.file
ORDER BY date DESC
You can just add another join condition. Also, note that implicit joins (having multiple tables in the from clause) isn't considered a good practice, and you should probably use explicit join clauses:
SELECT *
FROM tbl_uploads up
JOIN tbl_users us ON up.user_id = us.user_id
JOIN tbl_collab c ON c.user_id = up.user_id
ORDER BY date DESC

SUM value from query changes when i add inner join to the query

$sql = mysql_query("SELECT totals.*, sum(totals.payments) as total_payments
FROM totals
INNER JOIN users
GROUP BY totals.idseller;");
When i add the INNER JOIN the sum value is changed. Why?
In my SQL table i have one record in totals width this value: 8943.09 but when i do the some the result is giving me this value: 44715.45
What i am doing wrong?
$sql = mysql_query("SELECT totals.*, sum(totals.payments) as total_payments FROM totals
INNER JOIN users ON totals.idseller = users.idseller
GROUP BY users.UserName;");
Use this Hope this will help you.
When you INNER JOIN to another table, the returned data set is modified to only include rows that exist in both tables. In this case it is likely that there are rows in 'totals' that do not have a matching row in users - either the totals.idseller field might accept null values, or data has become orphaned when matching users have been deleted or edited.
If you want all data in 'totals' regardless of matching user you would user a LEFT JOIN instead in ms-sql, I suspect a similar approach will work in my-sql
You should give an "on" based on the ids. Such as like
inner join users on users.id = totals.idseller
Otherways the sql server will combine all possible rows in the tables, which is most cases not what you wish.
Because when you are adding inner join in your SQL Query, it means you are selecting the data which is common in both the tables.
EX:
SELECT * FROM TABLE_A
INNER JOIN TABLE_B
ON TABLE_A.ID = TABLE_B.ID
If you are joining users table which contains 5 records. By joining table, as there is no any column mapping, this sum-up 5 times and this is reason for showing different values.
Please let me know something wrong in it.
Thanks,
Umehs

Join mysql with multiple queries

I have three different SQL tables I need to join:
table "internet" with columns id|type|status
table "type_list" with columns id|type_name
table "status_list" with columns id|status_name
I want to output text from the two other tables (type_list, status_list) but not values as numbers which currently I have in table "internet".
I also don't want to make lazy programming - PHP array to make ID's equal to something like
$type_list = array("1"=>"VDSL2","2"=>"ADSL");
$status_list = array("1"=>"Pending","2"=>"Active");
because the text is already in the tables, i just dont know how to join them and output the text as query combined together in one query.
Use JOIN
SELECT i.id, type_name, status_name
FROM internet i
LEFT OUTER JOIN type_list t ON t.id = i.type
LEFT OUTER JOIN status_list s ON s.id= i.status
Read the MySQL doc for more informations.
Just write the select with the fields you want.
select internet.id,type_name,status_name from internet
inner join type_list
on type_list.id=internet.id
inner join status_list
on status_list.id=internet.id
For this you need a LEFT JOIN, like so:
SELECT i.id, t.type_name, s.status_name
FROM internet AS i
LEFT JOIN type_list AS t ON t.id = i.id
LEFT JOIN status_list AS s ON s.id= i.id
From your question, it is unclear what field you would like to join the queries on. In the above example, the queries are joined on the id field.
Please also note that the AS is not actually necessary, I have just put it in there to make it clear what is going on

Categories