One variable row inside another variable row - php

I have following script:
$sql = "SELECT * FROM `users`"
$q = mysql_query($sql) or die(mysql_error());
$row = mysql_fetch_array($q);
$sql1 = "SELECT * FROM `other_table`";
$q1 = mysql_query($sql1) or die(mysql_error());
$row1 = mysql_fetch_array($q1);
$item = $row1[$row['username']];
How can I set one variable row inside another, since it does not work. Basically, I need to select username, and then select column with user username from other table, in which is written user points.
I was thinking about adding:
$sql = "SELECT * FROM `users`"
$q = mysql_query($sql) or die(mysql_error());
$row = mysql_fetch_array($q);
$sql1 = "SELECT `".$row['username']."` FROM `other_table` WHERE `uid` = 1";
$q1 = mysql_query($sql1) or die(mysql_error());
$row1 = mysql_fetch_array($q1);
$item = $row1[xxxxxxxxxx]; // DONT KNOW HOW TO DEFINE IT, so it takes out found variable (there is only one).

Guess you want something like
SELECT * FROM table1 t1, table2 t2 WHERE t1.user_name = t2.user_name?
Think about using JOIN

$sql = "SELECT * FROM users;";
$q = mysql_query($sql) or die(mysql_error());
$row = mysql_fetch_array($q);
$sql1 = sprintf("SELECT * FROM other_table where username='%s';", $row['username']);
$q1 = mysql_query($sql1) or die(mysql_error());
$row1 = mysql_fetch_array($q1);
// now $row1 contains the tuple of this user and could access the variables are you would
// normally do e.g. $row1['ID']

SELECT * FROM users AS u INNER JOIN other_table AS o ON u.username = o.username
I'm assuming you want to do this because you want to be able to access all the rows from either table where a particular user name is the same (e.g. the data from users where username="john" and the data from other_table where username="john" for all usernames). No need to nest a result set to do this, just use a JOIN statement and then you can access all the columns as if it was a single result set (because it is):
$sql = "SELECT * FROM users AS u INNER JOIN other_table AS o ON u.username = o.username";
$q = mysql_query($sql) or die(mysql_error());
$row = mysql_fetch_array($q);
$item = $row['any_column'];
FYI you should list out the column you want to retrieve instead of using *, even if you want to retrieve them all, as it is better practice in case you add new columns in the future.

Related

Query in php returns null or empty value

I wrote the following query:
$query1 = "SELECT * FROM session WHERE Id_session IN (SELECT * FROM students_in_session WHERE Username = '$email')";
$res = mysqli_query($conn,$query1);
$query2 ="SELECT * FROM students_in_session WHERE Username='$email'";
$res2 = mysqli_query($conn,$query2);
if (!$res) {
die(mysqli_error($conn));
}else{
while ($row = mysqli_fetch_array($res)) {
print_r($row);
$course = $row['Degree'];
$date = $row['Date'];
$hour = $row['Hour'];
$room = $row['Room'];
}
}
if(!$res2){
die(mysqli_error($conn));
}else{
while ($row = mysqli_fetch_array($res2)) {
print_r($row);
$prof = $row['Professor'];
$assis = $row['Assistent'];
}
}
return "\n\nDegree: ".$course."\n"."Date: ".$date."\n"."Hour: ".$hour."\n"."Room: ".$room."\n"."Prof: ".$prof."\n"."Assistent: ".$assis;
}
Currently using phpmyadmin and testing the query returns the expected result,but using the query in the code the variables are all empty.
These are DB's Table:
session
|Id_Session|Date|Hour|Room|Degree|
students_in_session
|Id_Session|Code|Name|Surname|Username|Professor|Assistent|
In query1 you are just try to compare Id_session with the whole table you need to compere with the session id only.
Just replace this
$query1 = "SELECT * FROM session WHERE Id_session IN
(SELECT * FROM students_in_session WHERE Username = '$email')";
with
$query1 = "SELECT * FROM session WHERE Id_session IN
(SELECT Id_Session FROM students_in_session WHERE Username = '$email')";
I thing it will work for you.
$query1 = "SELECT * FROM session WHERE Id_session IN (SELECT * FROM students_in_session WHERE Username = '$email')";
In this query you must need to select only one column like
$query1 = "SELECT * FROM session WHERE Id_session IN (SELECT Id_session FROM students_in_session WHERE Username = '$email')";
Check it.
when you use a IN over a nested query, the nested query can return only one column:
SELECT * FROM session WHERE Id_session IN
(SELECT Id_Session FROM students_in_session WHERE Username = '$email')
However a nested query is not the best approach in your case, because MySQL will have to execute 2 queries. You would better do an INNER JOIN :
SELECT S.*
FROM session S
INNER JOIN students_in_session SS ON SS.Id_Session=S.Id_Session
WHERE SS.Username = '$email'

PHP / mysql join

I need to get 3 tables's values , from first I need to get aff_id where v_id = 5 , from second I need to get user id where aff_id = first's aff_id , and from third I need to get username , email , id where id = second's aff_id . I can't write correct mysql query to get data , please , help me to get it . Here is my wrong code
SELECT * FROM wp_vendor_affiliates WHERE vendor_id = 21 LEFT JOIN wp_affiliate_wp_affiliates
SELECT wp_vendor_affiliates.affiliate_id ,
wp_affiliate_wp_affiliates.user_id
FROM wp_vendor_affiliates
INNER JOIN wp_affiliate_wp_affiliates INNER JOIN
Please , hetp me , and correct my query . Thanks fot helping and for support
Use this code
$id1 = 5;
$query1 = "SELECT * FROM table1 WHERE v_id='{$id1}'";
$result1 = mysqli_query($con,$query1);
$row1 = mysqli_fetch_array($result1);
$id2 = $row1['aff_id'];
$query2 = "SELECT * FROM table2 WHERE aff_id='{$id2}'";
$result2 = mysqli_query($con,$query2);
$row2 = mysqli_fetch_array($result2);
$id3 = $row2['aff_id'];
$query3 = "SELECT * FROM table3 WHERE id='{$id3}'";
$result3 = mysqli_query($con,$query3);
$row3 = mysqli_fetch_array($result3);
$id2 = $row3['aff_id'];
Here $con is the connection to your database
$con= mysqli_connect("localhost","root","","data_base");
I used here connection to the localhost. which you'd have to change most certainly. It's a bit long but basic

Converting SQL Table ID into another field in PHP

So I'm trying to get the following to work;
//SEARCH USERPETS TABLE FOR ANYTHING USER OWNS
$query = "SELECT * FROM userpets WHERE owner = '$username'";
$result = mysqli_query($conn, $query);
$row = mysqli_fetch_assoc($result);
$userspets = $row['petid'];
//SEARCH PETS TABLE FOR LIST OF PET NAMES AND DETAILS
$query = "SELECT * FROM pets";
$result = mysqli_query($conn, $query);
$row = mysqli_fetch_assoc($result);
$petid = $row['id']
$petname = $row['petname'];
$petimg = $row['petimg']
//TURN PET ID INTO PET NAME AND IMAGE
echo "Pets: ".$userspets;
Essentially what I'm trying to do is this;
The 'userpets' table contains all 'owned' pets and the players username is displayed.
I want to grab all pets owned by that user and compare the petid with the 'pets' table.
I then want to take the pet's name and image from that table and 'echo' it onto the page.
Getting all the ids is fine, I just don't know how to make it convert the id's into the names.
Table Structure
You can use JOIN of MYSQL or Foreach of PHP
This is example by using PHP Foreach
$query = "SELECT * FROM userpets WHERE owner = '".$username."'";
$result = mysqli_query($conn, $query);
$petid = array(); // store all petid of this user
$rows = mysqli_fetch_all($result,MYSQLI_ASSOC);
foreach($rows as $row) {
$petid[] = $row['petid'];
}
$query = "SELECT * FROM pets WHERE id IN (".implode(",",$petid).")";
// implode will convert an array to string with delimete
// example array(0=>35, 1=>36, 2=>48) will be convert to "35,36,48"
// and above query should be : SELECT * FROM pets WHERE id IN (35,36,48)
$result = mysqli_query($conn, $query);
$pets = mysqli_fetch_assoc($result);
// dump it
echo "<pre>";
var_dump($pets);
echo "</pre>";
die;
Using MySQL Join
<?php
$query = "SELECT pet.id, pet.petname, pet.petimg, up.owner FROM pets as pet LEFT JOIN userpets as up ON pet.id = up.pet_id WHERE up.owner = '".$username."'";
I don't know how your tables look, but the best thing I can think of is, you have 3 tables one with Users, second with pets, and third "many to many" table lets call it ownedpets with users that own pets, because many users can own many pets. So ownedpets should have id_users that is connected to user.id and id_pets which is connected to pets_id. With that in mind I would do the fallowing query
SELECT *
FROM ownedpets
LEFT JOIN users
ON users.id = ownedpets.id_users
LEFT JOIN pets
ON pets.id = ownedpets.id_pets
WHERE users.id = $user_id
hope this helps

sql select from table then compare with other table in one statement

I have to tables in one database.
users
user_activate
I have to variables in php
$username = foo;
$key = jas823k123ksd34324;
Now I want to select from the table users the attribute user_id where user_username == $username
I do this with this statement
$sql = "SELECT user_id FROM users WHERE user_username = '$username'";
$result = mysqli_query($db, $sql);
while($row = mysqli_fetch_assoc($result)){
$user_id = $row['user_id'];
}
Now I want to select from the table user_activate the attribute user_activate_key where user_activate_key == $key;
For this I use this statement:
$sql2 = "SELECT user_activate_key FROM user_activate WHERE user_activate_key = '$key'";
$result2 = mysqli_query($db, $sql2);
while($row = mysqli_fetch_assoc($result)){
$user_key = row['user_activate_key'];
}
Can I do both statements in one statement?
As you've written it, two seperate queries is the correct way to do it. But I suspect that there's some kind of relationship between users and user_activate that might make what you're asking for make sense. Assuming that a user_activate_key is tied to a specific user_id, you could do something like the following:
select users.user_id, ua.user_activate_key
from users u
left join user_activate ua
on u.user_id = ua.user_id
and ua.user_activate_key = '$key'
where u.username = '$username'
The LEFT JOIN means that the user will be shown even if there isn't a matching user_activate_key record.

How to use php variables in mysql query while php variable contains mysql query?

How can I implement something like this in mysql?
$query1 = "SELECT id FROM table WHERE username = 'John'";
$query2 = "SELECT id FROM table WHERE username= 'Parsa'";
$query = "SELECT * FROM table WHERE id BETWEEN $query1 AND $query2";
$result = mysql_query($query) or die('Query faild'.mysql_error());
$myrecord = mysql_fetch_assoc($result);
Try this
$query1 ="SELECT GROUP_CONCAT(id) FROM table WHERE firstname in('John','Parsa')";
$query = "SELECT * FROM table WHERE id IN ($query1)";
you have two identical queries , you could just have one . and use IN , not BETWEEN.
You can put those 3 queries in to one query:
$query = "SELECT * FROM table WHERE id
BETWEEN
( SELECT id FROM table WHERE firstname = 'John' GROUP BY id )
AND
( SELECT id FROM table WHERE firstname = 'Parsa' GROUP BY id )
";
although your query doesn't mean anything; you need "()" for subqueries to work.
$query1 = "(SELECT id FROM table WHERE username = 'John')";
$query2 = "(SELECT id FROM table WHERE username= 'Parsa')";
$query = "SELECT * FROM table WHERE id BETWEEN $query1 AND $query2";
u can use a subselection:
SELECT * FROM table WHERE id BETWEEN ($query1) AND ($query2)
But be careful: The Subselection result must be an Integer.

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