Friday, 2 November 2018

How do I see what character set a MySQL database / table / column is?

What is the (default) charset for:
  • MySQL database
  • MySQL table
  • MySQL column

 Answers


Here's how I'd do it -
For Schemas:
SELECT default_character_set_name FROM information_schema.SCHEMATA 
WHERE schema_name = "schemaname";
For Tables:
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";
For Columns:
SELECT character_set_name FROM information_schema.`COLUMNS` 
WHERE table_schema = "schemaname"
  AND table_name = "tablename"
  AND column_name = "columnname";



For databases:
USE your_database_name;
show variables like "character_set_database";
-- or:
-- show variables like "collation_database";
Cf. this page. And check out the MySQL manual



For tables:
SHOW TABLE STATUS will list all the tables.
Filter using:
SHOW TABLE STATUS where name like 'table_123';



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
;



For tables and columns:
show create table your_table_name



For databases:
SHOW CREATE DATABASE "DB_NAME_HERE";

In creating a Database (MySQL), default character set/collation is always LATIN, instead that you have selected a different one on initially creating your database

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