Changing PDO to Mysqli [duplicate] - php

This question already has answers here:
How to convert PDO to mysqli?
(2 answers)
Closed 3 years ago.
I want to convert PDO code to mysqli and having some problem. I'm still new at this and I really don't understand PDO completely.
$query = "INSERT INTO gender(gender) VALUES (:gender)";
$statement = $conn->prepare($query);
$statement->execute(array('gender' => $_POST["gender"]));
$count = $statement->rowCount();
This is far I got.
$statement = $db->prepare ($query);;
$statement = array('gender' => $_POST["gender"]);
$count=mysqli_num_rows($query);
$statement = mysqli_fetch_array ($query);

Try this version:
$query = "INSERT INTO gender(gender) VALUES (?)";
$stmt = $mysqli->prepare($query);
$stmt->bind_param("s", $_POST["gender"]);
$stmt->execute();
$stmt->close();
You need to use the bind_param() function to bind parameters to your mysqli statement. Note that mysqli, unlike PDO, does not support named parameters. Instead, just use ? as a placeholder to which you bind your actual value later on.

Related

Multiple queries mysqli [duplicate]

This question already has answers here:
Reference - What does this error mean in PHP?
(38 answers)
What to do with mysqli problems? Errors like mysqli_fetch_array(): Argument #1 must be of type mysqli_result and such
(1 answer)
Closed 2 years ago.
I'm trying to input multiple queries guys using mysqli. Yet it's not populating the database. Any ideas?
$q2="UPDATE ticketinfo SET ticketstatus = $status where ticketno = $ticket;
insert into ticketinfo (remarks) values ('$remarks')";
$ex2= mysqli_multi_query($conn,$q2);
SQL queries should be executed sequentially. Never use mysqli_multi_query() with variable input. You should be using parameterized prepared statements. There is hardly any use case for mysqli_multi_query() at all.
Your code should look like this:
// your mysqli connection
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = new mysqli('localhost', 'username', 'password', 'dbname');
$mysqli->set_charset('utf8mb4'); // always set the charset
// First query
$stmt = $mysqli->prepare('UPDATE ticketinfo SET ticketstatus = ? WHERE ticketno = ?');
$stmt->bind_param('ss', $status, $ticket);
$stmt->execute();
// Second query
$stmt = $mysqli->prepare('INSERT INTO ticketinfo (remarks) VALUES (?)');
$stmt->bind_param('s', $remarks);
$stmt->execute();
I used two prepared statements and bound the input separately. This much better, cleaner and safer option than mysqli_multi_query().

Prepare select statement in php [duplicate]

This question already has answers here:
Can I bind an array to an IN() condition in a PDO query?
(23 answers)
MySQLi Bind Param with an array for IN [duplicate]
(2 answers)
Closed 5 years ago.
I can not figure out how I can prepare my select statement.
$query = "SELECT name, art FROM table_one WHERE name LIKE ? AND art IN ?";
if ($stmt = $db_link->prepare($query)) {
$stmt->bind_param("ss", $name, $art);
$stmt->execute();
if ($stmt->errno){
//Deal with error
}
$name = "%Marc%";
$art = "('green', 'blue', 'red')";
$stmt->execute();
$stmt->bind_result($name, $art);
while ($stmt->fetch()){
//Output data
}
}
So the problem is, that something does not work with the syntax in the prepared statement. This is my first attempt at preparing statements.
I had the query working before without using a prepared statement, but I am forced to use that now.
The old query looked like this:
$query = "SELECT name, art FROM table_one WHERE name LIKE '%$name%' AND art IN ('$art')";
Thank you for your help.

Safe MYSQL querying using user input [duplicate]

This question already has answers here:
How can I prevent SQL injection in PHP?
(27 answers)
Closed 5 years ago.
I just want to check how safe (if at all) my PHP-MYSQL queries are, I'm using user data which is coming through $_POST and then validating - the validation process of all data includes using mysqli_real_escape_string() on the string and trim(). The nature of some of my inputs however means that I don't restrict any characters on user input. Is what I'm doing safe and if not how could it be improved.
An example of an insert query (where $name and $description are $_POST data values which have been through a validation function.)
$sql = "INSERT INTO company(company_name, company_description) VALUES('".$name."', '".$description."')";
$result = mysqli_query($con, $sql);
An example of a select query (where $companyid is user input, real_escaped and stripped)
$sql = "SELECT * FROM events WHERE event_company=".$companyid."";
$result = mysqli_query($con, $sql);
Thanks in advance.
Here are your queries updated to use mysqli prepared statements.
$sql = "INSERT INTO `company` (`company_name`, `company_description`) VALUES(?, ?)";
$stmt = $con->prepare($sql);
$stmt->bind_param('ss',$name,$description); // ss is for string string
$stmt->execute();
$result = $stmt->get_result();
and
$sql = "SELECT * FROM `events` WHERE `event_company` = ?";
$stmt = $con->prepare($sql);
$stmt->bind_param('i',$companyid); // i indicates integer
$stmt->execute();
$result = $stmt->get_result();
There a type of hack called "SQL INJECTION" which can deceive your control. Read there for more information https://www.veracode.com/security/sql-injection

How To Use Variables In Mysql Queries With PDO [duplicate]

This question already has an answer here:
How to dynamically build queries with PDO
(1 answer)
Closed 7 years ago.
I want to use my variables in my mysql queries safely. Im using pdo for this. But i can't use pdo placeholders for table name.
This works;
$stmt = $db->prepare("SELECT * FROM table WHERE id=?");
$stmt->execute(array($id));
But this doesnt;
$stmt = $db->prepare("SELECT * FROM ? WHERE id=?");
$stmt->execute(array($table, $id));
What i'm doing wrong ?
Just do
$stmt = $db->prepare("SELECT * FROM ".$table." WHERE id=?");
$stmt->execute($id);
You can't use placeholders for table
That should not be a problem since the table name should be something you control.
here is the simple answer for you.
$statement = $db->prepare("SELECT * FROM table WHERE id=(:some_id)");
$statement->execute(array(':some_id' => $row['id']));
you should provide it with key => value format.

How to return the result of a mysqli_query so I can use it in another function? [duplicate]

This question already has answers here:
MySQLi equivalent of mysql_result()?
(12 answers)
Closed 9 years ago.
I am trying to return the user's id number from the database but I can't figure out how to return the result of the query. I used to use mysql_result() so what would I need to do now that I'm using mysqli?
function user_id_from_username($username){
$query = mysqli_query($conn, "SELECT `user_id` FROM `users` WHERE `username` = '$username'");
return (what?);
}
You haven't reaped one of the main benefits of moving from mysql to mysqli, which is using prepared statements to parameterize your queries and protect yourself from injection.
$query = mysqli_prepare($conn, "SELECT user_id FROM `users` WHERE username = ?");
mysqli_stmt_bind_param($query, "s", $username);
mysqli_stmt_execute($query);
mysqli_stmt_bind_result($query, $userid);
mysqli_stmt_fetch($query);
//$userid is now user_id
check this http://php.net/manual/en/mysqli.query.php for myqli_query usage. and this http://www.php.net/manual/en/class.mysqli-result.php on how to get the values from the result.

Categories