PHP returns the numeric encoding of the error message in the previous MySQL operation

php editor Banana will introduce you how to get the numeric encoding of the error message in the previous MySQL operation in PHP. MySQL provides a function mysql_errno(), which can be used to return the error number generated by the latest MySQL operation. By using this function, we can easily obtain the error information of MySQL operations in PHP, helping us better error handling and debugging. Let’s learn how to effectively use the mysql_errno() function in PHP to get the numeric encoding of MySQL error messages.

Use PHP to return MySQL error message numeric encoding

introduction

Errors may be encountered while processing mysql queries. In order to handle these errors effectively, it is crucial to understand the numerical encoding of error messages. This article will guide you to use php to obtain Mysql error message numeric encoding.

Method to get the digital code of error message

1. mysqli_errno()

mysqli_errno() The function returns the most recent error number for the current MySQL connection. The syntax is as follows:

$error_number = mysqli_errno($link);

Where $link is the link identifier pointing to the MySQL connection.

2. mysqli_error()

mysqli_error() The function returns the most recent error message for the current MySQL connection. The error message includes the error number and the syntax is as follows:

$error_string = mysqli_error($link);

$error_number = (int) substr($error_string, 0, strpos($error_string, ":"));

3. PDO::errorCode()

When using PHP Data Objects (PDO), you can use the PDO::errorCode() method to get the error message numeric encoding. The syntax is as follows:

$error_number = $pdo->errorCode();

Example

$link = mysqli_connect("localhost", "user", "passWord", "database");

if (!$link) {
echo "Error: Unable to connect to MySQL." . PHP_EOL;
echo "Error number: " . mysqli_errno($link) . PHP_EOL;
exit;
}

$query = "SELECT * FROM non_existent_table";
$result = mysqli_query($link, $query);

if (!$result) {
echo "Error: Unable to execute query." . PHP_EOL;
echo "Error number: " . mysqli_errno($link) . PHP_EOL;
exit;
}

Reference error code

The meaning of MySQL error codes can be found in the MySQL documentation: https://dev.mysql.com/doc/refman/8.0/en/error-messages.html

Other considerations

• Make sure you are connected to MySQL when using mysqli_errno() or mysqli_error().
• mysqli_errno() Only the most recent error number is returned, so when executing multiple queries, be sure to call it after each query.
• PDO::errorCode() returns an error number both before and after executing the query.
• By handling numerical encoding of error messages, you can write more robust and information-rich applications.

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