lc_time_names

Description

lc_time_names specifies the language in which date and month names and their abbreviations are displayed.

Limitations

• Query the variable

  • Global-level operation

    In the sys tenant or a user tenant, you can execute the SHOW VARIABLES statement to query the variable at the global level or query the information_schema.GLOBAL_VARIABLES view (in MySQL mode) for the variable at the global level.

  • Session-level operation

    In the sys tenant or a user tenant, you can execute the SHOW VARIABLES statement to query the variable at the session level or query the information_schema.SESSION_VARIABLES view (in MySQL mode) for the variable at the session level.

• Modify the variable

  • Global-level operation

    • In the sys tenant, you can directly change the value of the variable at the global level.

    • In a MySQL user tenant, you must have the SUPER or ALTER SYSTEM privilege to change the value of the variable at the global level.

  • Session-level operation

    In the sys tenant or a user tenant, you can directly change the value of the variable at the session level for the current tenant.

Attributes

Considerations

This variable affects the output of the DATE_FORMAT(), DAYNAME(), and MONTHNAME() functions, but does not affect the output of the STR_TO_DATE() or GET_FORMAT() function.

• DATE_FORMAT() function

  In this function, lc_time_names affects the language and format of the month and day of the week in the output string. The month and day of the week in the output string are named based on the English naming conventions in en_US mode and based on the Chinese naming conventions in zh_CN mode.

• DAYNAME() function

  In this function, lc_time_names affects the language and format of the day of the week returned. The day of the week is returned in English in en_US mode and in Chinese in zh_CN mode.

• MONTHNAME() function

  In this function, lc_time_names affects the language and format of the month returned. The month is returned in English in en_US mode and in Chinese in zh_CN mode.

Examples

Take the output of a date function as an example:

1. Set the language in which the date and month names and their abbreviations are displayed to English.

   • Session-level operation

     obclient> SET lc_time_names='en_US';
     

   • Global-level operation

     obclient> SET GLOBAL lc_time_names='en_US';
     

2. Query the current value of lc_time_names.

   obclient> show variables like "lc_time_names";
   

   The query result is as follows:

   +---------------+-------+
   | Variable_name | Value |
   +---------------+-------+
   | lc_time_names | en_US |
   +---------------+-------+
   1 row in set (0.015 sec)
   

3. Use the functions to query the input date.

   • Use the DATE_FORMAT() function to query the format of the input date.

     obclient> select DATE_FORMAT('2023-01-06','%Y-%m-%d');
     

     The query result is as follows:

     +--------------------------------------+
     | DATE_FORMAT('2023-01-06','%Y-%m-%d') |
     +--------------------------------------+
     | 2023-01-06                           |
     +--------------------------------------+
     1 row in set (0.001 sec)
     

   • Use the DAYNAME() function to query the day of the week of the input date.

     obclient> select DAYNAME('2023-01-06');
     

     The query result is as follows:

     +-----------------------+
     | DAYNAME('2023-01-06') |
     +-----------------------+
     | Friday                |
     +-----------------------+
     1 row in set (0.000 sec)
     

   • Use the MONTHNAME() function to query the month of the input date.

     obclient> select MONTHNAME('2023-01-06');
     

     The query result is as follows:

      +-------------------------+
      | MONTHNAME('2023-01-06') |
      +-------------------------+
      | January                    |
      +-------------------------+
      1 row in set (0.001 sec)