[#MDEV-22233] information_schema.TABLES does not show table's default character set

The information_schema.TABLES table does not currently show a table's default character set.

For example, see here:

MariaDB [(none)]> SELECT * FROM information_schema.TABLES WHERE TABLE_SCHEMA='db1' AND TABLE_NAME='tab'\G

*************************** 1. row ***************************

   TABLE_CATALOG: def

    TABLE_SCHEMA: db1

      TABLE_NAME: tab

      TABLE_TYPE: BASE TABLE

          ENGINE: InnoDB

         VERSION: 10

      ROW_FORMAT: Dynamic

      TABLE_ROWS: 0

  AVG_ROW_LENGTH: 0

     DATA_LENGTH: 16384

 MAX_DATA_LENGTH: 0

    INDEX_LENGTH: 0

       DATA_FREE: 0

  AUTO_INCREMENT: NULL

     CREATE_TIME: 2020-04-13 17:09:37

     UPDATE_TIME: NULL

      CHECK_TIME: NULL

 TABLE_COLLATION: utf8mb4_unicode_ci

        CHECKSUM: NULL

  CREATE_OPTIONS:

   TABLE_COMMENT:

MAX_INDEX_LENGTH: 0

       TEMPORARY: N

It does have a TABLE_COLLATION column, which can be used to infer the table's default character set.

However, the documentation would be simpler and clearer if the information_schema.TABLES table had *both* the default character set and the collation.

The information_schema.SCHEMATA table already contains both values for databases:

MariaDB [(none)]> SELECT * FROM information_schema.SCHEMATA WHERE SCHEMA_NAME='db1'\G

*************************** 1. row ***************************

              CATALOG_NAME: def

               SCHEMA_NAME: db1

DEFAULT_CHARACTER_SET_NAME: utf8mb4

    DEFAULT_COLLATION_NAME: utf8mb4_unicode_ci

                  SQL_PATH: NULL

The table's default character set can currently be found from SHOW CREATE TABLE:

MariaDB [(none)]> SHOW CREATE TABLE db1.tab\G

*************************** 1. row ***************************

       Table: tab

Create Table: CREATE TABLE `tab` (

  `id` int(11) NOT NULL,

  `str` varchar(50) COLLATE utf8mb4_unicode_ci DEFAULT NULL,

  PRIMARY KEY (`id`)

) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci

[MDEV-22233] information_schema.TABLES does not show table's default character set Created: 2020-04-13 Updated: 2020-04-13
Status:	Open
Project:	MariaDB Server
Component/s:	Character Sets, Information Schema
Fix Version/s:	None

[MDEV-22233] information_schema.TABLES does not show table's default character set Created: 2020-04-13 Updated: 2020-04-13