Question

MySQL错误代码（如1054）有什么意义？

错误消息包含实际信息，因此必须有一些方法可以从错误代码中获取更多信息。

但是，与错误消息相比，我可以使用什么来从错误代码中获取任何内容？

通常你会得到两个：

<?PHP
$db_link = new mysqli($hostname, $username, $password, $database);

$statement = $db_link->prepare('SELECT SomeFieldThatDoesNotExist FROM Person');
$statement->execute();

if(!$statement) {
    $specific_error = $db_link->error;
    $error_number = $db_link->errno;
}
?>

想象一下，我有错误1054（参见：https://dev.mysql.com/doc/refman/5.5/en/error-messages-server.html#error_er_bad_field_error）。

只有数字1054，我可以使用什么来获取实际的MySQL错误信息呢？

Answer 1

使用SHOW ERRORS;

手动：https://mariadb.com/kb/en/mariadb/show-errors/

SELECT f();
ERROR 1305 (42000): FUNCTION f does not exist

SHOW COUNT(*) ERRORS;
+-----------------------+
| @@session.error_count |
+-----------------------+
|                     1 |
+-----------------------+

SHOW ERRORS;
+-------+------+---------------------------+
| Level | Code | Message                   |
+-------+------+---------------------------+
| Error | 1305 | FUNCTION f does not exist |
+-------+------+---------------------------+

Answer 2

在Github上使用MySQL错误代码PHP库：https://github.com/HoldOffHunger/mysql-errors-codes。

正常的错误消息传递风格：

$db_link = new mysqli($this->hostname,$this->username,$this->password);
print($db_link->connect_errno . " : " . $db_link->connect_error);

正常错误消息输出：

13236 : Message: Newly created data directory SOMEDIRECTORY is unusable. You can safely remove it.

全新，更完整的错误消息样式：

$mysql_error = new MySQLErrorCode();
$error_codes = $mysql_error->ErrorCodes();

print_r($error_codes[13236]);

输出：

13236 : Message: Newly created data directory SOMEDIRECTORY is unusable. You can safely remove it.

'13236' => [
    'error_code' => '13236',
    'internal_code' => 'ER_DATA_DIRECTORY_UNUSABLE',
    'message_template' => 'Message: Newly created data directory %s is unusable. You can safely remove it.',
    'sql_state' => 'HY000',
    'version_information' => 'ER_DATA_DIRECTORY_UNUSABLE was added in 8.0.13.'
],

仅从错误代码获取MySQL错误消息

2 个答案: