MYSQL select query does not give any output [closed] - php

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My SQL query is not working. Below is my code and note that in that table query worked fine and gives output. But in PHP by using mysqli_num_rows(), mysqli_fetch_assoc() and mysqli_fetch_array() all doesn't works for me.
My DB connection is :
$conn = mysqli_connect($servername, $username, $password, $db);
Note : My DB Connectivity is fine.
$username = mysqli_real_escape_string($conn, $_POST['username']);
$password = mysqli_real_escape_string($conn, $_POST['password']);
$query = mysqli_query($conn, "SELECT * FROM `admin` WHERE `username`='$username'");
This query results true in PHPMyAdmin and returns false in PHP with the above functions. Can anyone answer is I made a mistake?
And I am tried that query to execute in following methods :
$row = mysqli_fetch_assoc(); // Results No Data
$data = mysqli_fetch_array($query); // Results No Data
$num = mysqli_num_rows($query); // Results 0 Data

you may execute the query before use it :
<?php
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$conn = mysqli_connect("localhost", "my_user", "my_password", "world");
$query = "SELECT Name, CountryCode FROM City ORDER BY ID DESC";
$result = mysqli_query($conn , $query);
/* fetch associative array */
while ($row = mysqli_fetch_assoc($result)) {
printf("%s (%s)\n", $row["Name"], $row["CountryCode"]);
}

You mast to run mysqli_query function for receive result from DB:
$username = mysqli_real_escape_string($conn, $_POST['username']);
$query = "SELECT * FROM `admin` WHERE `username`='$username'";
$result = mysqli_query($mysqli, $query);
$row = mysqli_fetch_assoc($result);
print_r($row);
PHP MySQL sandbox here

Related

Get the sum of all the hours [closed]

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I am doing a project with PHP and MySQL. I have this problem.
This is my code
<?php
$proyecto = $_POST['id'];
$servername = "localhost";
$username = "dbuser";
$password = "dbpass";
$dbname = "proyectos";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "SELECT `horas`, `trabajador` FROM `horas` WHERE `proyecto` LIKE '$proyecto' ";
$result = $conn->query($sql);
$conn->close();
?>
It takes a parameter from a post request and do a search in the database database looks like this:
So I want to get as result the sum of all the hours (horas column) that are made by the same worker (trabajador column). Example of result:
Prueba1: 8 hours in total, Prueba2: 9 hours in total
I am stuck trying to dinf they way to sum when 1 or more fields must be the same, I hope someone can help me with this. Thanks!
You must use sum function to add the number of hours for each worker along with GROUP BY clause to group workers.Formatted Query is like:
SELECT SUM(horas) AS Hours,`trabajador`
FROM `horas`
WHERE `proyecto`
LIKE '%".$proyecto."%'
GROUP BY `trabajador`
In your code,
$select = "
SELECT SUM(horas) AS Hours, `trabajador`
FROM `horas`
WHERE `proyecto` LIKE ?
GROUP BY `trabajador`
";
$sth = $conn->prepare($select);
$sth->execute(['%'.$proyecto.'%']);
/* Fetch all of the remaining rows in the result set */
print("Fetch all rows in the result set:\n");
$result = $sth->fetchAll(\PDO::FETCH_ASSOC);
print_r($result);
Note: You better switch to MYSQL prepared statements to keep your data secure and for better database connectivity practices.
Note answer by maniksidana explains how to use SUM() and GROUP BY and is in general valid. However, it mixes mysqli and PDO approches. Here you have sample how to use it with mysqli (as your question uses it) and why it's important to use prepared statements at all. Just add some dummy data to your table end execute it. Personally I'd suggest to go with PDO only instead, but it's matter of taste.
INSERT INTO `horas` (`fecha`, `horas`, `proyecto`, `trabajador`) VALUES
('2020-08-08', 3, 'foo bar baz', 'Joker1'),
('2020-08-09', 4, 'ello pomello', 'Joker2');
<?php
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$proyecto = "ProyectpDePrueba'; DELETE FROM horas WHERE 1; -- bye bye data";
$proyecto = "ProyectpDePrueba";
$proyecto = "ProyectpDePrueba' OR 1=1 -- no more execution";
// Wrong
$sql = "
SELECT SUM(horas) AS Hours, `trabajador`
FROM `horas`
WHERE `proyecto` LIKE '$proyecto'
GROUP BY `trabajador`
";
$result = $conn->query($sql);
echo '<pre>Wrong' . PHP_EOL;
while ($row = mysqli_fetch_assoc($result)) {
print_r($row);
}
// Correct
$sql = "
SELECT SUM(horas) AS Hours, `trabajador`
FROM `horas`
WHERE `proyecto` LIKE ?
GROUP BY `trabajador`
";
$stmt = $conn->prepare($sql);
$stmt->bind_param('s', $proyecto);
$stmt->execute();
$result = $stmt->get_result();
echo PHP_EOL . 'Corrcet' . PHP_EOL;
while ($row = $result->fetch_assoc()) {
print_r($row);
}
$conn->close();

PHP I have a database connect file, should i put my database querie functions in the same file [closed]

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to explain my question better, i have two files: dbh.inc.php
$dbServername = "localhost";
$dbUsername = "xxxxx";
$dbPassword = "secret";
$dbName = "databasename";
$conn = mysqli_connect($dbServername, $dbUsername, $dbPassword, $dbName);
mysqli_set_charset($conn,"utf8");
if (!$conn) {
die("Connection failed: ".mysqli_connect_error());
}
$table1 = "users";//1
$table2 = "userprofile";//2
$table3 = "twofactorauth";//3
And: database-query.func.php
function selectdb($data, $values, $url) {
include ('dbh.inc.php');
extract($data);
extract($values);
switch ($data['table']) {
case '1':
$table = $table1;
break;
case '2':
$table = $table2;
break;
case '3':
$table = $table3;
break;
}
$sql = "SELECT $rows FROM $table WHERE $where;";
print_r($sql);
die();
$stmt = mysqli_stmt_init($conn);
if (!mysqli_stmt_prepare($stmt, $sql)) {
mysqli_stmt_close($stmt);
mysqli_close($conn);
header("Location: ".$url."?error=sqlerror");
die();
} else {
$amount = str_repeat('s', count($values));
$values = array_values($values);
mysqli_stmt_bind_param($stmt, $amount, ...$values);
mysqli_stmt_execute($stmt);
$result = mysqli_stmt_get_result($stmt);
$getResult = mysqli_fetch_assoc($result);
mysqli_stmt_close($stmt);
mysqli_close($conn);
$new = array_push($getResult, 'true');
return $getResult;
}
}
So the first holds database connection, and the latter has dynamic querys for insert, update and select for the moment. And i am wondering should i combine the two files, to one. Since every time i need my connect i always use one of my querys and same on the other way around?
Also 2 bonus questions: as you see in my connect file i have my table names and i use numbers in my other files and in the functions connect numbers to names.
Lastly should i use PDO, why?
To answer your question in general - yes, you can put a helper function in the same file where sql connection is made.
However, the code of your actual function is questionable at the very least. Or, to tell you truth, your function selectdb() is a torture for a programmer and shouldn't be stored anywhere. Stick to natural SQL queries written as is. You don't need numbers to represent tables. You don't need $rows variable. Everything could be written right in the SQL string. All you will need is a simple helper function that would reduce the amount of code required to run a query.
Here is an example of such mysqli include file
Once it's included in in your script, you can use it to run any mysql query, to any table, with any list of variables. Check out the following example (you can copy and paste the following code block to your file and run it as is):
<?php
require 'mysqli.php';
#Create a temporary table
$conn->query("CREATE temporary TABLE tmp_mysqli_helper_test
(id int auto_increment primary key, name varchar(9))");
# populate it with sample data
$sql = "INSERT INTO tmp_mysqli_helper_test (name) VALUES (?),(?),(?)";
$stmt = prepared_query($conn, $sql, ['Sam','Bob','Joe']);
echo "Affected rows: $stmt->affected_rows\n";
echo "Last insert id: $conn->insert_id\n";
# Getting rows in a loop
$sql = "SELECT * FROM tmp_mysqli_helper_test WHERE id > ?";
$res = prepared_query($conn, $sql, [1])->get_result();
while ($row = $res->fetch_assoc())
{
echo "{$row['id']}: {$row['name']}\n";
}
# Getting one row
$id = 1;
$sql = "SELECT * FROM tmp_mysqli_helper_test WHERE id=?";
$row = prepared_query($conn, $sql, [$id])->get_result()->fetch_assoc();
echo "{$row['id']}: {$row['name']}\n";
# Update
$id = 1;
$new = 'Sue';
$sql = "UPDATE tmp_mysqli_helper_test SET name=? WHERE id=?";
$affected_rows = prepared_query($conn, $sql, [$new, $id])->affected_rows;
echo "Affected rows: $affected_rows\n";
# Getting an array of rows
$start = 0;
$limit = 10;
$sql = "SELECT * FROM tmp_mysqli_helper_test LIMIT ?,?";
$all = prepared_query($conn, $sql, [$start, $limit])->get_result()->fetch_all(MYSQLI_ASSOC);
foreach ($all as $row)
{
echo "{$row['id']}: {$row['name']}\n";
}
As you can see, a proper helper function can keep all the flexibility and readability of SQL and reduce the amount of code at the same time.

How to assign a DB value to a PHP variable? [closed]

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I am trying to assign a DB value to a PHP variable. The database is SQL. I want the database value to be $HaveOfficialPage. How can I do this?
$connection = mysqli_connect('localhost', '', '', '');
if($connection){
echo "Connected";
}
else {
die("Database connection failed");
}
$query = "SELECT HaveOfficialPage FROM vf_Category";
$result = mysqli_query($connection, $query);
if(!$result){
die("Query failed" . mysqli_error());
}
If you’re trying to iterate through the results:
while ($row = mysqli_fetch_row($result)) {
$haveOfficialPage = $row[0];
// do something with the variable
}
If you’re getting only one record:
$row = mysqli_fetch_assoc($result);
$haveOfficialPage = $row["HaveOfficialPage"];
To select a category with a condition, use prepared statements
$paths = explode("/",$_SERVER["REQUEST_URI"]);
$category = end($paths);
$query = "SELECT HaveOfficialPage FROM vf_Category WHERE category_name = ?";
$stmt = mysqli_prepare($connection, $query);
mysqli_stmt_bind_param($stmt, "s", $category);
mysqli_stmt_bind_result($stmt, $haveOfficialPage); // here we assign the result to your variable
mysqli_stmt_fetch($stmt); // fetch
echo $haveOfficialPage;

Update points of a user in mysql database using php [closed]

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I am trying to take a string username from my android app and use that username to add 5 points to that specific users account.
Example:
My database now: user_id name username password points
1 test test test 0
What I want: user_id name username password points
1 test test test 5
Here is the php code I'm using right now, something must be wrong with it:
<?php
$con = mysqli_connect("localhost", "id177667_root", "***", "id177667_loginb");
$username = $_POST["username"];
$sql = "UPDATE user ". "SET points = points + 5 ". "WHERE username = $username" ;
$response = mysqli_query($sql, $con);
?>
You confused the parameters for mysqli_query. It should be mysqli_query($con, $sql); instead. Also there are a couple of other problems - this should work:
<?php
$con = mysqli_connect("localhost", "id177667_root", "***", "id177667_loginb");
$username = mysqli_real_escape_string($con, $_POST["username"]);
$sql = "UPDATE user SET points = points + 5 WHERE username = '$username'" ;
$response = mysqli_query($con, $sql);
?>
As it was suggested, prepared statements are the preferred way to go. So you could do this... tested it now, and it works for me:
<?php
$points = 5;
// Connect to database (credentials should not be stored in code...)
$con = new mysqli("localhost", "id177667_root", "***", "id177667_loginb");
// Check if connection succeeded
if ($con->connect_error)
die("Connection error: " . $con->connect_error);
// Prepare statement
if ($st = $con->prepare("UPDATE user SET points = points + ? WHERE username = ?")) {
// Bind parameters (i for integer value, s for string)
$st->bind_param("is", $points, $_POST["username"]);
// Execute statement
$st->execute();
// Close statement
$st->close();
} else {
// Prepare failed: report error
die("Prepare failed: " . $con->error);
}
// Close DB connection
$con->close();
?>

Printing last 10 entries in database [closed]

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So I'm working on a website that has a list of novels in a database with some basic info about them. I'd like to make a table of the most recent additions to the database. I'm using PHP and SQL and this is what I've got so far.
<?php
$servername = "localhost";
$username = "root";
$password = "password";
$database = "novels";
// Create connection
$conn = new mysqli($servername, $username, $password, $database);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
// Select ten most recent entries
SELECT `N_ID`, `NAME`, `DATE_RELEASED`, `GENRES` FROM basic_info ORDER BY N_ID DESC LIMIT 10
?>
I"m new to PHP And SQL so what I can gather is that I've made a connection to the database and have pulled the information from the latest 10 entries. Now I'm just not sure how to print them.
Any help is appreciated!
Try to use PDO if you can. Also you could use lower case for your columns to avoid case sensitivity issues.
You have to "wrap" your SELECT query in a variable (e.g. $sql) to be able to pass it in your php code.
error_reporting(E_ALL);
ini_set("display_errors", 1);
$servername = "localhost";
$username = "root";
$password = "password";
$database = "novels";
try {
//Make your connection handler to your database
$conn = new PDO("mysql:host=".$servername.";dbname=".$database, $username, $password, array(PDO::ATTR_ERRMODE => PDO::ERRMODE_WARNING));
$sql = "SELECT `N_ID`, `NAME`, `DATE_RELEASED`, `GENRES` FROM basic_info ORDER BY N_ID DESC LIMIT 10";
$stmt = $conn->prepare($sql);
//Execute the query
$stmt->execute();
$result = $stmt->fetchAll();
//Fetch the results
foreach ($result as $row) {
echo '<p>'.$row['NAME'].'</p>';
}
} catch(PDOException $e) {
echo $e->getMessage();
die();
}

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