How to Execute Multiple MySQL Queries in PHP with Transactions and Exception Handling?

Executing Multiple MySQL Queries using PHP

To execute consecutive MySQL statements in PHP, one can leverage the mysqli_query() function. However, it's essential to avoid concatenating multiple queries into a single string, as this can lead to syntax errors.

Syntax Correction:

The provided code snippet contains a syntax error. To resolve it, the multiple queries should be executed separately, as shown below:

$conn = new mysqli("localhost", "root", "password", "database"); // Establish database connection

$tmpQuery = "CREATE TEMPORARY TABLE tmp SELECT * FROM event_categoriesBU WHERE id = 1";
$result = $conn->query($tmpQuery);

$updateQuery = "UPDATE tmp SET>

This approach eliminates the need for string concatenation and ensures that each query is executed independently.

Using Transactions:

For complex transactions involving multiple queries, it's recommended to use transactions to ensure atomicity. Transactions can guarantee that all queries within the transaction are either all successful or none are. To use transactions, one can follow these steps:

$conn->begin_transaction();

// Execute multiple queries here

$conn->commit(); // Commit the transaction if successful

Exception Handling:

To handle exceptions that may occur during query execution, one should enable exceptions by using set_exception_handler(function($errno, $errstr) { $conn->rollback(); $conn->close(); }). This will ensure that any exceptions that arise will result in the transaction being rolled back and the connection being closed.

Additional Considerations:

• Prepared Statements: For security and performance reasons, it's ideal to use prepared statements when working with user input to prevent SQL injection vulnerabilities.
• Consider PDO: PDO (PHP Data Objects) is a more advanced and versatile database abstraction layer that offers several advantages over mysqli, including support for multiple drivers, prepared statements, and transactions.

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