MySQL 8.4 發行說明
某些 SHOW 語句的擴展伴隨著 INFORMATION_SCHEMA 的實作
INFORMATION_SCHEMA 是一個資訊資料庫，所以它的名稱會包含在 SHOW DATABASES 的輸出中。同樣地，SHOW TABLES 可以搭配 INFORMATION_SCHEMA 使用以取得其表格的清單
mysql> SHOW TABLES FROM INFORMATION_SCHEMA;
+---------------------------------------+
| Tables_in_INFORMATION_SCHEMA |
+---------------------------------------+
| CHARACTER_SETS |
| COLLATIONS |
| COLLATION_CHARACTER_SET_APPLICABILITY |
| COLUMNS |
| COLUMN_PRIVILEGES |
| ENGINES |
| EVENTS |
| FILES |
| KEY_COLUMN_USAGE |
| PARTITIONS |
| PLUGINS |
| PROCESSLIST |
| REFERENTIAL_CONSTRAINTS |
| ROUTINES |
| SCHEMATA |
| SCHEMA_PRIVILEGES |
| STATISTICS |
| TABLES |
| TABLE_CONSTRAINTS |
| TABLE_PRIVILEGES |
| TRIGGERS |
| USER_PRIVILEGES |
| VIEWS |
+---------------------------------------+
SHOW COLUMNS 和 DESCRIBE 可以顯示個別 INFORMATION_SCHEMA 表格中關於欄位的資訊。
接受 LIKE 子句來限制顯示列的 SHOW 語句，也允許使用 WHERE 子句來指定所選取列必須滿足的更一般條件
SHOW CHARACTER SET
SHOW COLLATION
SHOW COLUMNS
SHOW DATABASES
SHOW FUNCTION STATUS
SHOW INDEX
SHOW OPEN TABLES
SHOW PROCEDURE STATUS
SHOW STATUS
SHOW TABLE STATUS
SHOW TABLES
SHOW TRIGGERS
SHOW VARIABLES如果存在 WHERE 子句，則會針對 SHOW 語句所顯示的欄位名稱進行評估。例如，SHOW CHARACTER SET 語句會產生以下輸出欄位
mysql> SHOW CHARACTER SET;
+----------+-----------------------------+---------------------+--------+
| Charset | Description | Default collation | Maxlen |
+----------+-----------------------------+---------------------+--------+
| big5 | Big5 Traditional Chinese | big5_chinese_ci | 2 |
| dec8 | DEC West European | dec8_swedish_ci | 1 |
| cp850 | DOS West European | cp850_general_ci | 1 |
| hp8 | HP West European | hp8_english_ci | 1 |
| koi8r | KOI8-R Relcom Russian | koi8r_general_ci | 1 |
| latin1 | cp1252 West European | latin1_swedish_ci | 1 |
| latin2 | ISO 8859-2 Central European | latin2_general_ci | 1 |
...若要搭配 SHOW CHARACTER SET 使用 WHERE 子句，您會參考這些欄位名稱。例如，下列語句會顯示預設排序規則包含字串 'japanese' 的字元集相關資訊
mysql> SHOW CHARACTER SET WHERE `Default collation` LIKE '%japanese%';
+---------+---------------------------+---------------------+--------+
| Charset | Description | Default collation | Maxlen |
+---------+---------------------------+---------------------+--------+
| ujis | EUC-JP Japanese | ujis_japanese_ci | 3 |
| sjis | Shift-JIS Japanese | sjis_japanese_ci | 2 |
| cp932 | SJIS for Windows Japanese | cp932_japanese_ci | 2 |
| eucjpms | UJIS for Windows Japanese | eucjpms_japanese_ci | 3 |
+---------+---------------------------+---------------------+--------+此語句會顯示多位元組字元集
mysql> SHOW CHARACTER SET WHERE Maxlen > 1;
+---------+---------------------------------+---------------------+--------+
| Charset | Description | Default collation | Maxlen |
+---------+---------------------------------+---------------------+--------+
| big5 | Big5 Traditional Chinese | big5_chinese_ci | 2 |
| cp932 | SJIS for Windows Japanese | cp932_japanese_ci | 2 |
| eucjpms | UJIS for Windows Japanese | eucjpms_japanese_ci | 3 |
| euckr | EUC-KR Korean | euckr_korean_ci | 2 |
| gb18030 | China National Standard GB18030 | gb18030_chinese_ci | 4 |
| gb2312 | GB2312 Simplified Chinese | gb2312_chinese_ci | 2 |
| gbk | GBK Simplified Chinese | gbk_chinese_ci | 2 |
| sjis | Shift-JIS Japanese | sjis_japanese_ci | 2 |
| ucs2 | UCS-2 Unicode | ucs2_general_ci | 2 |
| ujis | EUC-JP Japanese | ujis_japanese_ci | 3 |
| utf16 | UTF-16 Unicode | utf16_general_ci | 4 |
| utf16le | UTF-16LE Unicode | utf16le_general_ci | 4 |
| utf32 | UTF-32 Unicode | utf32_general_ci | 4 |
| utf8mb3 | UTF-8 Unicode | utf8mb3_general_ci | 3 |
| utf8mb4 | UTF-8 Unicode | utf8mb4_0900_ai_ci | 4 |
+---------+---------------------------------+---------------------+--------+