B.1 Error Message Sources and Components

This section discusses how error messages originate within MySQL and the components they contain.

Error Message Sources

Error messages can originate on the server side or the client side:

On the server side, error messages may occur during the startup and shutdown processes, as a result of issues that occur during SQL statement execution, and so forth.
- The MySQL server writes some error messages to its error log. These indicate issues of interest to database administrators or that require DBA action.
- The server sends other error messages to client programs. These indicate issues pertaining only to a particular client. The MySQL client library takes errors received from the server and makes them available to the host client program.
Client-side error messages are generated from within the MySQL client library, usually involving problems communicating with the server.

Example server-side error messages written to the error log:

This message produced during the startup process provides a status or progress indicator:

2018-10-28T13:01:32.735983Z 0 [Note] [MY-010303] [Server] Skipping
generation of SSL certificates as options related to SSL are specified.

This message indicates an issue that requires DBA action:

2018-10-02T03:20:39.410387Z 768 [ERROR] [MY-010045] [Server] Event Scheduler:
[evtuser@localhost][myschema.e_daily] Unknown database 'mydb'

Example server-side error message sent to client programs, as displayed by the mysql client:

mysql> SELECT * FROM no_such_table;
ERROR 1146 (42S02): Table 'test.no_such_table' doesn't exist

Example client-side error message originating from within the client library, as displayed by the mysql client:

shell> mysql -h no-such-host
ERROR 2005 (HY000): Unknown MySQL server host 'no-such-host' (0)

Whether an error originates from within the client library or is received from the server, a MySQL client program may respond in varying ways. As just illustrated, the client may display the error message so the user can take corrective measures. The client may instead internally attempt to resolve or retry a failed operation, or take other action.

Inhaltsverzeichnis Haut

Error Message Components

When an error occurs, error information includes several components: an error code, SQLSTATE value, and message string. These components have the following characteristics:

Error code: This value is numeric. It is MySQL-specific and is not portable to other database systems.
Each error number has a corresponding symbolic value. Examples:
- The symbol for server error number 1146 is ER_NO_SUCH_TABLE.
- The symbol for client error number 2005 is CR_UNKNOWN_HOST.
The set of error codes used in error messages is partitioned into distinct ranges; see Error Code Ranges.
Error codes are stable across General Availability (GA) releases of a given MySQL series. Before a series reaches GA status, new codes may still be under development and are subject to change.
SQLSTATE value: This value is a five-character string (for example, '42S02'). SQLSTATE values are taken from ANSI SQL and ODBC and are more standardized than the numeric error codes. The first two characters of an SQLSTATE value indicate the error class:
- Class = '00' indicates success.
- Class = '01' indicates a warning.
- Class = '02' indicates “not found.” This is relevant within the context of cursors and is used to control what happens when a cursor reaches the end of a data set. This condition also occurs for SELECT ... INTO var_list statements that retrieve no rows.
- Class > '02' indicates an exception.
For server-side errors, not all MySQL error numbers have corresponding SQLSTATE values. In these cases, 'HY000' (general error) is used.
For client-side errors, the SQLSTATE value is always 'HY000' (general error), so it is not meaningful for distinguishing one client error from another.
Message string: This string provides a textual description of the error.

Inhaltsverzeichnis Haut

Error Code Ranges

The set of error codes used in error messages is partitioned into distinct ranges, each with its own purpose:

1 to 999: Global error codes. This error code range is called “global” because it is a shared range that is used by the server as well as by clients.
When an error in this range originates on the server side, the server writes it to the error log, padding the error code with leading zeros to six digits and adding a prefix of MY-.
When an error in this range originates on the client side, the client library makes it available to the client program with no zero-padding or prefix.
1,000 to 1,999: Server error codes reserved for messages sent to clients.
2,000 to 2,999: Client error codes reserved for use by the client library.
3,000 to 4,999: Server error codes reserved for messages sent to clients.
5,000 to 5,999: Error codes reserved for use by X Plugin for messages sent to clients.
10,000 to 49,999: Server error codes reserved for messages to be written to the error log (not sent to clients).
When an error in this range occurs, the server writes it to the error log, padding the error code with leading zeros to six digits and adding a prefix of MY-.
50,000 to 51,999: Error codes reserved for use by third parties.

The server handles error messages written to the error log differently from error messages sent to clients:

When the server writes a message to the error log, it pads the error code with leading zeros to six digits and adds a prefix of MY- (examples: MY-000022, MY-010048).
When the server sends a message to a client program, it adds no zero-padding or prefix to the error code (examples: 1036, 3013).

Suchen Sie im MySQL-Handbuch

Deutsche Übersetzung

Sie haben gebeten, diese Seite auf Deutsch zu besuchen. Momentan ist nur die Oberfläche übersetzt, aber noch nicht der gesamte Inhalt.

Wenn Sie mir bei Übersetzungen helfen wollen, ist Ihr Beitrag willkommen. Alles, was Sie tun müssen, ist, sich auf der Website zu registrieren und mir eine Nachricht zu schicken, in der Sie gebeten werden, Sie der Gruppe der Übersetzer hinzuzufügen, die Ihnen die Möglichkeit gibt, die gewünschten Seiten zu übersetzen. Ein Link am Ende jeder übersetzten Seite zeigt an, dass Sie der Übersetzer sind und einen Link zu Ihrem Profil haben.

Vielen Dank im Voraus.

Dokument erstellt 26/06/2006, zuletzt geändert 26/10/2018
Quelle des gedruckten Dokuments:https://www.gaudry.be/de/mysql-rf-error-message-components.html

Die Infobro ist eine persönliche Seite, deren Inhalt in meiner alleinigen Verantwortung liegt. Der Text ist unter der CreativeCommons-Lizenz (BY-NC-SA) verfügbar. Weitere Informationen auf die Nutzungsbedingungen und dem Autor.

Referenzen

Manuel MySQL : https://dev.mysql.com/

Diese Verweise und Links verweisen auf Dokumente, die während des Schreibens dieser Seite konsultiert wurden, oder die zusätzliche Informationen liefern können, aber die Autoren dieser Quellen können nicht für den Inhalt dieser Seite verantwortlich gemacht werden.
Der Autor Diese Website ist allein dafür verantwortlich, wie die verschiedenen Konzepte und Freiheiten, die mit den Nachschlagewerken gemacht werden, hier dargestellt werden. Denken Sie daran, dass Sie mehrere Quellinformationen austauschen müssen, um das Risiko von Fehlern zu reduzieren.

Inhaltsverzeichnis Haut