Set MySQL Variables with MySQLi (not PHP variables)

Hey everyone,

I'm currently working on a project where I need to set MySQL variables using MySQLi, not PHP variables. I've been trying to find a solution, but I haven't had much luck so far.

To provide some context, I have a PHP script that connects to a MySQL database using MySQLi. Within this script, I need to set a few MySQL variables like "max_allowed_packet" and "wait_timeout" before executing my queries.

I know how to set these variables using regular SQL queries, but I specifically need to achieve this using MySQLi. I want to ensure that the changes I make to these variables are applied only to the current MySQLi connection and not affect other connections to the same database.

I've tried searching online, but most of the examples I found were related to using PHP variables to set MySQL variables, which is not what I need.

If anyone has any experience or knowledge on how to accomplish this task using MySQLi, I would greatly appreciate your assistance. Any guidance or example code would be extremely helpful.

Thank you all in advance for your help!

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veum.josh

July 04 2023 at 11:31 AM

Hey there!

I've encountered a similar situation before, where I needed to set MySQL variables using MySQLi. Fortunately, I found a way to accomplish this.

To set MySQL variables using MySQLi, you can utilize the `query()` method of the MySQLi connection object. Here's an example code snippet to illustrate how it can be done:

php
$mysqli = new mysqli("localhost", "username", "password", "database");



// Set max_allowed_packet variable

$mysqli->query("SET @@global.max_allowed_packet = <desired_value>");

$mysqli->query("SET @@session.max_allowed_packet = <desired_value>");



// Set wait_timeout variable

$mysqli->query("SET @@global.wait_timeout = <desired_value>");

$mysqli->query("SET @@session.wait_timeout = <desired_value>");

In the above code, make sure to replace `<desired_value>` with the actual value you want to set for each variable.

By using `@@global` in the query, you are changing the value globally for MySQL, affecting all connections. On the other hand, using `@@session` sets the value only for the current MySQLi connection. So, keep that in mind depending on your requirements.

I hope this helps you achieve your goal of setting MySQL variables using MySQLi. If you have any further questions, feel free to ask. Good luck with your project!

Helpful (14)

daisy.zboncak

June 21 2023 at 01:20 PM

Hey all!

I recently faced a similar dilemma and managed to figure out how to set MySQL variables using MySQLi. Sharing my experience here!

To set MySQL variables using MySQLi, you can utilize prepared statements. This technique helped me ensure the security and integrity of my queries. Here's an example to guide you through the process:

php
$mysqli = new mysqli("localhost", "username", "password", "database");



// Prepare statement

$stmt = $mysqli->prepare("SET @var_name = ?");



// Bind the variable value

$varValue = "desired_value";

$stmt->bind_param("s", $varValue);



// Execute the statement

$stmt->execute();



// Close the statement

$stmt->close();

In the above snippet, you need to replace `@var_name` with the actual variable name you wish to set and `"desired_value"` with the value you want to assign. The `"s"` in `bind_param()` indicates that the variable is a string; you can adjust it accordingly if you're working with other data types.

Using prepared statements with MySQLi provides an added layer of security by automatically escaping any user input, reducing the risk of SQL injections.

Remember to execute each `SET` statement separately for each variable you want to set. Once you're done, don't forget to close the statement to free up resources.

I hope this approach helps you set your MySQL variables using MySQLi in a secure manner. If you have further queries or need additional help, feel free to ask. Good luck with your project!

Helpful (11)

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alvera48

June 13 2023 at 04:41 AM

Hey folks,

I recently had a similar requirement where I needed to set MySQL variables using MySQLi, and I found a different approach that worked for me. Thought I'd share my experience here!

Instead of using regular queries or prepared statements, I utilized the `multi_query()` method in MySQLi to set multiple variables in a single call. Here's an example code snippet to illustrate how it can be done:

php
$mysqli = new mysqli("localhost", "username", "password", "database");



// Construct the query string

$query = "SET @var1 = 'desired_value1'; ";

$query .= "SET @var2 = 'desired_value2'; ";



// Execute the query

$mysqli->multi_query($query);



// Fetch any result sets (if applicable)

while ($mysqli->more_results()) {

    $mysqli->next_result();

    $mysqli->store_result();

}



// Close the connection

$mysqli->close();

In the above code, you can construct your query string by concatenating multiple `SET` statements together as needed. Each statement should end with a semicolon. The `multi_query()` method allows you to execute the entire query string at once.

After executing the query, you can use a loop to fetch any result sets if your query generates them. Then, don't forget to close the MySQLi connection to release resources.

I found this method to be quite efficient as it reduces the number of calls to the database. However, keep in mind that any errors in the query will be reported only for the first statement, so make sure your query is properly constructed.

I hope this alternative approach helps you set MySQL variables using MySQLi effectively. If you have any further questions, feel free to ask. Best of luck with your project!

Helpful (7)

Set MySQL Variables with MySQLi (not PHP variables)

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