I have a problem with integers in MySQL. I am trying to update a cell which stores an integer. However, I have problem with the type of that cell. Actually it is type is set to int but when I retrive the data I always get 0 and I belive it is because of the problem about how I am trying to get it. Here is my code sample;
function updateNumb($username) {
$query = "SELECT `num` FROM `profiles` WHERE `nick`='" . $username . "'";
$result = mysql_query($query, $this->conn) or die(mysql_error());
$row = mysql_fetch_array($result, MYSQL_ASSOC);
$row['num'] = $row['num'] + 1;
$numb = (int)$row['num'] + 1;
//here I update the data.
$query = "UPDATE `profiles` SET `num`=" . $numb . " WHERE `nick`='".$username."'";
mysql_query($query, $this->conn) or die(mysql_error());
return $numb;
}
Can it be because of mysql_fetch_array stuff? Or how could I overcome this problem?
replace partisayisi with num
There is nothing wrong with the code you provided, maybe it's not doing what you really need, for example num is incremented twice, but there are no visible mistakes that would make it return 0, at least not in what we can see.
Make sure you provide valid username, try to echo your query before sending to mysql to see what it really looks like, maybe try this query yourself in mysql client or phpmyadmin to see what's going on.
Also if the only thing you need is to increment num for some user you can do it in one update, you don't need to use select to get that number:
UPDATE profiles set num=num+1 WHERE nick='somenick'
Related
I am a novice when it comes to PHP but I don't understand if my syntax is wrong in this statement, or how would I grab an int from my MySQL server.
I know that my server credentials are working fine. How would I fix this statement to give me a returned integer of the number of reviews in the userinfo table?
$numberofpreviousreviews = mysql_query("SELECT `number_of_reviews` FROM `userinfo`") or die(mysql_error()); //Check to see how many reviews user has previously created
$amountofreviews = $numberofpreviousreviews + 1;
$query2 = mysql_query("ALTER TABLE userinfo ADD `amountofreviews` VARCHAR(10000)") or die(mysql_error()); //Make another column in database for the new review
You need to fetch your results after you run your query. There are several ways to do this but using mysql_fetch_assoc() will work for you.
$numberofpreviousreviews = mysql_query("SELECT `number_of_reviews` FROM `userinfo`") or die(mysql_error()); //Check to see how many reviews user has previously created
$row = mysql_fetch_assoc($numberofpreviousreviews);
$amountofreviews = $row['number_of_reviews'] + 1;
FYI, you shouldn't be using mysql_* functions anymore. They are deprecated and going away. You should use mysqli or PDO.
Assume you have a table userinfo which has the following structure and data :
Scenario #1 :
If you want to retrieve the all number_of_reviews, then do like this,
$query = "SELECT `number_of_reviews` FROM `userinfo`";
$result = mysqli_query($db,$query);
while ($row = mysqli_fetch_assoc($result)) {
echo "Number of reviews : " . $row['number_of_reviews'] . "<br/>";
}
It will give you,
Number of reviews : 20
Number of reviews : 40
Since, the result has many rows, it will display like above.
Scenario #2:
If you want to retrieve only the specific number_of_reviews for some user id (which is unique). I take id as 1 as a example here. Then do like,
$query2 = "SELECT `number_of_reviews` FROM `userinfo` WHERE `id` = 1";
$result2 = mysqli_query($db,$query2);
while ($row2 = mysqli_fetch_assoc($result2)) {
echo $row2['number_of_reviews'] . "<br/>";
}
This will print,
20.
Because, number_of_reviews is 20 for id 1.
I am trying to get the last value of a field during a new registration.
before insert data into the table, I want to create a user id number according to the last registered user's id number. to do that I use this:
//to reach the last value of userID field;
$sql = "SELECT userID FROM loto_users ORDER BY userID DESC LIMIT 1";
$result = mysql_query($sql);
while($row = mysql_fetch_array($result))
{
$value = $row['userID'];
echo "$value"; //not resulting here
}
$userID = $value+1;
so, the userID becomes 1.
The weird thing is, I could capable to use exact same code in another php file and works fine.
I would like to say that, rest of the code works fine. No problem with db connections or any other things you can tell me.
Note that: When I run the same query line in the mysql interface, I can get the value I want. I mean $sql line.
Your problem is in this code:
{
$svalue = $row['userID'];
----^
echo "$value"; //not resulting here
}
$userID = $value+1;
Change to $value.
But the right answer is to define userID to be auto-incrementing. That way, the database does the work for you. After inserting the row, you can do:
SELECT LAST_INSERT_ID()
To get the last value.
I solved the problem. Here;
$sql = "SELECT userID FROM loto_users ORDER BY userID DESC LIMIT 1";
$result = mysql_query($sql);
$user_info = $result->fetch_assoc();
$value = intval($user_info["userID"]);
$userID = $value+1;
Thanks everyone.
If you mark the userID field as autoincrement in you mysql table.
You won't need to set the userID and db increase the userID for you. You can get the assigned userID using the mysql_insert_id() function. Here is an example from php.net
mysql_query("INSERT INTO mytable (product) values ('kossu')");
printf("Last inserted record has id %d\n", mysql_insert_id());
Here is another example for your case
mysql_query("INSERT INTO 'loto_users'('username',...) values('usernameValue',...)");
echo "New User id is ".mysql_insert_id();
Was hoping someone could give me some help. I have been trying to learn pagination but have run into an issue. when I run this to get my total rows count:
$sql = "SELECT COUNT (*) FROM item WHERE fid='17'";
$query = mysqli_query($con, $sql);
$row = mysqli_fetch_row($query);
$rows = $row[0];
$rows comes back with no value, I am under the impression that $rows should contain the total number of records from item with the fid of 17, when I run SELECT COUNT (*) FROM item WHERE fid='17' in phpmyadmin it returns 98 which is the correct count. Directly before the above code I use this code to connect to the db, which I use again later to display the records which works fine.
$con=mysqli_connect("$host","$username","$password","$dbname");
// Check connection
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
This statement displays records later in the script
$sql = mysqli_query($con,"SELECT * FROM item WHERE fid='17' ORDER BY id DESC $limit ");
So there is data and the info is correct.
I have been following this tutorial on the subject http://www.developphp.com/view.php?tid=1349 and it works like a charm on his example in the video, all I have changed is the database particulars to mine. Can't figure this one out, been stuck for days so now I am bothering you fine folks.
Update: Changed
$query = mysqli_query($con, $sql);
$row = mysqli_fetch_row($query);
$rows = $row[0];
to
if ($result=mysqli_query($con,$sql))
{
// Return the number of rows in result set
$rows=mysqli_num_rows($result);
// Free result set
mysqli_free_result($result);
}
And everything is working now. Still wish I knew what was wrong with my original code but I will be moving on. Thanks Phil Perry for all your help this morning!
Well, you could SELECT * FROM... and then call mysqli_num_rows($query). Probably slower than SELECT count(*). BTW, I presume that item is not a reserved word in SQL. You can always wrap table and field names in backticks (not quotes ' or "). You could also try SELECT count(*) AS myCount....
try this,
$sql = "SELECT COUNT(*) FROM item WHERE fid='17'";
$query = mysqli_query($sql);
$row = mysqli_fetch_array($query);
$rows = $row[0];
I'm running a very simple query that I think should work. The only thing that I haven't done before is put a php variable in the WHERE clause of the query. The variable $X is a numerical value, say 100. When I run this query, I just get a value of 0 returned. Am I doing something obviously stupid?
SELECT generator_64k.n
FROM generator_64k
WHERE generator_64k.n<= '$X'
I've looked around the web and also tried this:
SELECT generator_64k.n
FROM generator_64k
WHERE generator_64k.n<= '" . $X . "'
But this also just returns 0.
Any ideas? Thanks in advance.
$query = "SELECT generator_64k.n FROM generator_64k WHERE generator_64k.n<= {$X};";
Try this one, or post your PHP code.
<?php
$X = 100;
$query = "SELECT n FROM generator_64k WHERE n <= $X";
$result = mysql_query($query);
if (!$result) {
echo ('Query error: ' . mysql_error());
}
E.g of php and using variables
$query = "select * from table1 where col1 <=" .$myVariable;
$result= mysql_query($query);
The mysql_query() function returns false on error (false == 0), otherwise, it returns a resource. mysql_query does not return the value from the result set. You must use mysql_fetch_assoc or something similar to fetch the rows from the result set.
Also, ensure that you wrap the query in double quotes so PHP can expand the variable $X.
Use mysql_error to fetch the error from the last call to mysql_query.
make it like this
$sql="select `username` from `users` where id='$newid';";
mysql_query($sql);
here $newid is the int value.
The symbol used before and after username, to get this you have to press the key just below esc .
You can't have ' around your numeric value. MySQL will treat it as string.
You should do this instead
" WHERE number <= " . (int)$val . " .. "
// or (but not recommended due to security problem)
" WHERE number <= $val "
What's the best way with PHP to read a single record from a MySQL database? E.g.:
SELECT id FROM games
I was trying to find an answer in the old questions, but had no luck.
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$id = mysql_result(mysql_query("SELECT id FROM games LIMIT 1"),0);
$link = mysql_connect('localhost','root','yourPassword')
mysql_select_db('database_name', $link);
$sql = 'SELECT id FROM games LIMIT 1';
$result = mysql_query($sql, $link) or die(mysql_error());
$row = mysql_fetch_assoc($result);
print_r($row);
There were few things missing in ChrisAD answer. After connecting to mysql it's crucial to select database and also die() statement allows you to see errors if they occur.
Be carefull it works only if you have 1 record in the database, because otherwise you need to add WHERE id=xx or something similar to get only one row and not more. Also you can access your id like $row['id']
Using PDO you could do something like this:
$db = new PDO('mysql:host=hostname;dbname=dbname', 'username', 'password');
$stmt = $db->query('select id from games where ...');
$id = $stmt->fetchColumn(0);
if ($id !== false) {
echo $id;
}
You obviously should also check whether PDO::query() executes the query OK (either by checking the result or telling PDO to throw exceptions instead)
Assuming you are using an auto-incrementing primary key, which is the normal way to do things, then you can access the key value of the last row you put into the database with:
$userID = mysqli_insert_id($link);
otherwise, you'll have to know more specifics about the row you are trying to find, such as email address. Without knowing your table structure, we can't be more specific.
Either way, to limit your SELECT query, use a WHERE statement like this:
(Generic Example)
$getID = mysqli_fetch_assoc(mysqli_query($link, "SELECT userID FROM users WHERE something = 'unique'"));
$userID = $getID['userID'];
(Specific example)
Or a more specific example:
$getID = mysqli_fetch_assoc(mysqli_query($link, "SELECT userID FROM users WHERE userID = 1"));
$userID = $getID['userID'];
Warning! Your SQL isn't a good idea, because it will select all rows (no WHERE clause assumes "WHERE 1"!) and clog your application if you have a large number of rows. (What's the point of selecting 1,000 rows when 1 will do?) So instead, when selecting only one row, make sure you specify the LIMIT clause:
$sql = "SELECT id FROM games LIMIT 1"; // Select ONLY one, instead of all
$result = $db->query($sql);
$row = $result->fetch_assoc();
echo 'Game ID: '.$row['id'];
This difference requires MySQL to select only the first matching record, so ordering the table is important or you ought to use a WHERE clause. However, it's a whole lot less memory and time to find that one record, than to get every record and output row number one.
One more answer for object oriented style. Found this solution for me:
$id = $dbh->query("SELECT id FROM mytable WHERE mycolumn = 'foo'")->fetch_object()->id;
gives back just one id. Verify that your design ensures you got the right one.
First you connect to your database. Then you build the query string. Then you launch the query and store the result, and finally you fetch what rows you want from the result by using one of the fetch methods.
$link = mysql_connect('localhost','root','yourPassword')
mysql_select_db('database',$link);
$sql = 'SELECT id FROM games'
$result = mysql_query($sql,$link);
$singleRow = mysql_fetch_array($result)
echo $singleRow;
Edit: So sorry, forgot the database connection. Added it now
'Best way' aside some usual ways of retrieving a single record from the database with PHP go like that:
with mysqli
$sql = "SELECT id, name, producer FROM games WHERE user_id = 1";
$result = $db->query($sql);
$row = $result->fetch_row();
with Zend Framework
//Inside the table class
$select = $this->select()->where('user_id = ?', 1);
$row = $this->fetchRow($select);
The easiest way is to use mysql_result.
I copied some of the code below from other answers to save time.
$link = mysql_connect('localhost','root','yourPassword')
mysql_select_db('database',$link);
$sql = 'SELECT id FROM games'
$result = mysql_query($sql,$link);
$num_rows = mysql_num_rows($result);
// i is the row number and will be 0 through $num_rows-1
for ($i = 0; $i < $num_rows; $i++) {
$value = mysql_result($result, i, 'id');
echo 'Row ', i, ': ', $value, "\n";
}
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$db = new mysqli('localhost', 'tmp', 'tmp', 'your_db');
$db->set_charset('utf8mb4');
if($row = $db->query("SELECT id FROM games LIMIT 1")->fetch_row()) { //NULL or array
$id = $row[0];
}
I agree that mysql_result is the easy way to retrieve contents of one cell from a MySQL result set. Tiny code:
$r = mysql_query('SELECT id FROM table') or die(mysql_error());
if (mysql_num_rows($r) > 0) {
echo mysql_result($r); // will output first ID
echo mysql_result($r, 1); // will ouput second ID
}
Easy way to Fetch Single Record from MySQL Database by using PHP List
The SQL Query is SELECT user_name from user_table WHERE user_id = 6
The PHP Code for the above Query is
$sql_select = "";
$sql_select .= "SELECT ";
$sql_select .= " user_name ";
$sql_select .= "FROM user_table ";
$sql_select .= "WHERE user_id = 6" ;
$rs_id = mysql_query($sql_select, $link) or die(mysql_error());
list($userName) = mysql_fetch_row($rs_id);
Note: The List Concept should be applicable for Single Row Fetching not for Multiple Rows
Better if SQL will be optimized with addion of LIMIT 1 in the end:
$query = "select id from games LIMIT 1";
SO ANSWER IS (works on php 5.6.3):
If you want to get first item of first row(even if it is not ID column):
queryExec($query) -> fetch_array()[0];
If you want to get first row(single item from DB)
queryExec($query) -> fetch_assoc();
If you want to some exact column from first row
queryExec($query) -> fetch_assoc()['columnName'];
or need to fix query and use first written way :)