I want to delete the record when the id column is equal to $id. Would this work?
$query = "DELETE FROM $TableName WHERE id=$id";
As a side i also want to set the number of rows that can be deleted to a
limit of 1. I know i have to use limit but i am unsure on its parameters
You could do
mysqli_query = ($con, "DELETE FROM `$TableName` WHERE id='$id' LIMIT 1");
That should do it exactly my friend
I have a created a function changeIp() to disabled a record and return a new record. As you can see I am using 3 SQL query.
Is there a better way doing to reduce number of SQL queries?
function changeIp() {
// Find 1 record which is not disabled
$SQL = "SELECT * FROM ip WHERE disable = 0 order by id limit 1";
$qIp = mysql_query($SQL) or die(mysql_error());
$qrow = mysql_fetch_assoc($qIp);
// Disable a record
$id = $qrow['id'];
$SQL = "UPDATE ip set disable = 1 WHERE id = $id";
mysql_query($SQL) or die(mysql_error());
// Return the next record
$SQL = "SELECT * FROM ip WHERE disable = 0 order by id limit 1";
$qIp = mysql_query($SQL) or die(mysql_error());
$qrow = mysql_fetch_assoc($qIp);
return $qrow['ip'];
}
You should use "mysqli" or php, but that is a separate matter from your question.
Your queries are fine. You can't really do an update and select in a single statement. You can improve performance with an index on ip(id, disable). And, an index on ip(disable, id) might also be beneficial, depending on a number of factors.
i got a point system that are like people can upgrade to [PRO1] user. everyones rights(pro1,pro2,user) are stored in my mysql users table. But i want to make a little feed, that shows the latest one that upgraded to [PRO1]. the upgrade code:
$insert = "UPDATE `users` SET `points` = (`points`-50) WHERE `username` = '".$username."' and points > 50";
mysql_query($insert);
if (mysql_affected_rows() > 0)
{
// other codes
$insert = "UPDATE users SET rights=' [PRO1]' WHERE `username` = '".$username."'";
mysql_query($insert);
header('location: succesupgrade.php');
}else{
echo "You don't have enough points";
}
?>
the upgrade code works fine(just incase i need to add a time/date. and tha code for where i want the"'username' wast the last to upgrade to [PRO1]" is in this code:
<?php
require("dbc.php");
$query = mysql_query("select * from users WHERE rights='[PRO1]' order by right DESC limit 1") or die(mysql_error());
while($array = mysql_fetch_array($query)) {
echo "{$array['username']}<br>";
}
?>was the last to upgrade to:
<?php
require("dbc.php");
$query = mysql_query("select * from users WHERE rights='[PRO1]' order by rights DESC limit 1") or die(mysql_error());
while($array = mysql_fetch_array($query)) {
echo "{$array['rights']}<br>";
}
?>
But that code gives me this error:You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'DESC limit 1' at line 1
order by right must be order by rights in the first query of the second code block.
That query is going to do nothing to tell you who the last user to upgrade to rights='[PRO1]'. That is just a string field. You would need some sort of datetime/timestamp field that is updated when the users rights change, by which you can make the sort.
You also don't need to do 2 queries. You have two queries doing the exact same thing.
Just do:
SELECT username FROM users WHERE rights='[PRO1]' ORDER BY update_timestamp DESC LIMIT 1
Where update_timestamp would be the field that is updated when the rights change.
The reason is because right is a used keyword, you need a back stroke to solve this :;
Like :
select * from `users` WHERE rights='[PRO1]' order by `rights` DESC limit 1
I need to copy the value in a column named TEAM from one row into another row. Both rows need to have the same team name. This is my query that doesn't work:
$query = "UPDATE profiles SET team = (SELECT team FROM profiles WHERE id = '$coach_id') WHERE id = '$player_id'";
I have tried removing single quotes, removing "FROM profiles", changing value to table.value, tried to give a newdata.clan alias, and I have even tried changing the values to integers instead of parameters. Nothing works, and this is what I get:
Error: You have an error in your SQL
syntax; check the manual that
corresponds to your MySQL server
version for the right syntax to use
near 'WHERE id = '') WHERE id = ''' at
line 3
$query1 = "SELECT team FROM profiles WHERE id = '$coach_id'";
/* get the value of the first query and assign it to a variable like $team_name */
$query2 = "UPDATE profiles SET team = '$team_name' WHERE id = '$player_id'";
Also, you should surround your PHP variables in curly braces:
$query = "UPDATE profiles SET team = \"(SELECT team FROM profiles WHERE id = '{$coach_id}')\" WHERE id = '{$player_id}'";
From the MySQL manual:
"Currently, you cannot update a table
and select from the same table in a
subquery."
Source: http://dev.mysql.com/doc/refman/5.0/en/update.html
Use the method that FinalForm wrote:
<?
$coach_id = 2;
$player_id = 1;
$query1 = "SELECT team FROM profiles WHERE id = '$coach_id'";
$rs = mysql_query($query1);
if ($row = mysql_fetch_array($rs)) {
$team_name = $row['team'];
$query2 = "UPDATE profiles SET team = '$team_name' WHERE id = '$player_id'";
mysql_query($query2);
// Done, updated if there is an id = 1
} else {
// No id with id = 2
}
?>
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 :)