在创建新数据库时，将生成一些必要的表

在“information_schema”中此路径

“列”——>关于列

“表”——>表

例如，如果您需要查看表中的所有列名和类型

SELECT COLUMN_NAME,COLUMN_TYPE FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = 'your_schema_name' AND TABLE_NAME = 'your_table_name'

显示像'character_set_%'或'collation%'这样的变量

数据库:

SELECT SCHEMA_NAME 'database', default_character_set_name 'charset', DEFAULT_COLLATION_NAME 'collation' FROM information_schema.SCHEMATA;

示例输出:

mysql> SELECT SCHEMA_NAME 'database', default_character_set_name 'charset', DEFAULT_COLLATION_NAME 'collation' FROM information_schema.SCHEMATA;
+----------------------------+---------+--------------------+
| database                   | charset | collation          |
+----------------------------+---------+--------------------+
| information_schema         | utf8    | utf8_general_ci    |
| drupal_demo1               | utf8    | utf8_general_ci    |
| drupal_demo2               | utf8    | utf8_general_ci    |
| drupal_demo3               | utf8    | utf8_general_ci    |
| drupal_demo4               | utf8    | utf8_general_ci    |
| drupal_demo5               | latin1  | latin1_swedish_ci  |

...

+----------------------------+---------+--------------------+
55 rows in set (0.00 sec)

mysql> 

SELECT TABLE_SCHEMA,
       TABLE_NAME,
       CCSA.CHARACTER_SET_NAME AS DEFAULT_CHAR_SET,
       COLUMN_NAME,
       COLUMN_TYPE,
       C.CHARACTER_SET_NAME
  FROM information_schema.TABLES AS T
  JOIN information_schema.COLUMNS AS C USING (TABLE_SCHEMA, TABLE_NAME)
  JOIN information_schema.COLLATION_CHARACTER_SET_APPLICABILITY AS CCSA
       ON (T.TABLE_COLLATION = CCSA.COLLATION_NAME)
 WHERE TABLE_SCHEMA=SCHEMA()
   AND C.DATA_TYPE IN ('enum', 'varchar', 'char', 'text', 'mediumtext', 'longtext')
 ORDER BY TABLE_SCHEMA,
          TABLE_NAME,
          COLUMN_NAME
;

在创建新数据库时，将生成一些必要的表

在“information_schema”中此路径

“列”——>关于列

“表”——>表

例如，如果您需要查看表中的所有列名和类型

SELECT COLUMN_NAME,COLUMN_TYPE FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = 'your_schema_name' AND TABLE_NAME = 'your_table_name'

我是这么做的——

对于模式(或数据库-它们是同义词):

SELECT default_character_set_name FROM information_schema.SCHEMATA 
WHERE schema_name = "schemaname";

表:

SELECT CCSA.character_set_name FROM information_schema.`TABLES` T,
       information_schema.`COLLATION_CHARACTER_SET_APPLICABILITY` CCSA
WHERE CCSA.collation_name = T.table_collation
  AND T.table_schema = "schemaname"
  AND T.table_name = "tablename";

列:

SELECT character_set_name FROM information_schema.`COLUMNS` 
WHERE table_schema = "schemaname"
  AND table_name = "tablename"
  AND column_name = "columnname";