如何查看MySQL数据库/表/列的字符集是什么？

Question

什么是(默认)字符集:

• MySQL数据库

• MySQL表

• MySQL专栏

Answer 1

这是我怎么做的 -

对于架构:

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

对于表格:

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";

对于列:

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

Answer 2

对于列:

SHOW FULL COLUMNS FROM table_name;

Answer 3

对于数据库:

USE your_database_name;
show variables like "character_set_database";
-- or:
-- show variables like "collation_database";

参看 这个页面.并查看MySQL手册

Answer 4

对于服务器上的所有数据库:

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

输出:

+----------------------------+---------+--------------------+
| database                   | charset | collation          |
+----------------------------+---------+--------------------+
| information_schema         | utf8    | utf8_general_ci    |
| my_database                | latin1  | latin1_swedish_ci  |
...
+----------------------------+---------+--------------------+

对于单个数据库:

mysql> USE my_database;
mysql> show variables like "character_set_database";

输出:

    +----------------------------+---------+
    | Variable_name              |  Value  |
    +----------------------------+---------+
    | character_set_database     |  latin1 | 
    +----------------------------+---------+

获取表的排序规则:

mysql> USE my_database;
mysql> SHOW TABLE STATUS WHERE NAME LIKE 'my_tablename';

或 - 将输出create table的完整SQL:

mysql> show create table my_tablename

获取列的排序规则:

mysql> SHOW FULL COLUMNS FROM my_tablename;

输出:

+---------+--------------+--------------------+ ....
| field   | type         | collation          |
+---------+--------------+--------------------+ ....
| id      | int(10)      | (NULL)             |
| key     | varchar(255) | latin1_swedish_ci  |
| value   | varchar(255) | latin1_swedish_ci  |
+---------+--------------+--------------------+ ....

Answer 5

对于表格:

SHOW TABLE STATUS 将列出所有表格.

过滤使用:

SHOW TABLE STATUS where name like 'table_123';

Answer 6

对于数据库:

只需使用以下命令:

USE db_name;
SELECT @@character_set_database;
-- or:
-- SELECT @@collation_database;

Answer 7

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
;

Answer 8

要查看数据库的默认排序规则:

USE db_name;
SELECT @@character_set_database, @@collation_database;

要查看表的排序规则:

SHOW TABLE STATUS where name like 'table_name';

要查看列的排序规则:

SHOW FULL COLUMNS FROM table_name;

Answer 9

我总是只看SHOW CREATE TABLE mydatabase.mytable.

对于数据库,您似乎需要查看SELECT DEFAULT_CHARACTER_SET_NAME FROM information_schema.SCHEMATA.

Answer 10

对于表和列:

show create table your_table_name

Answer 11

对于数据库:

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> 

Answer 12

对于数据库:

SHOW CREATE DATABASE "DB_NAME_HERE";

在创建数据库(MySQL)时,默认字符集/排序规则始终是LATIN,而是在最初创建数据库时选择了不同的字符集/排序规则

Answer 13

正如许多人先前所写，SHOW FULL COLUMNS应该是获取列信息的首选方法。缺少的是在此之后无需直接到达元数据表即可获取字符集的方法：

SHOW FULL COLUMNS FROM my_table WHERE Field = 'my_field'
SHOW COLLATION WHERE Collation = 'collation_you_got'