Mysql批量修改字符集

show VARIABLES like ‘character%’;

alter database 数据库名 character set utf8mb4;

ALTER TABLE 表名 ENGINE=InnoDB DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

SELECT TABLE_NAME,CONCAT(‘ALTER TABLE  ‘,TABLE_NAME,’ ENGINE=InnoDB DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;’) executeSQL FROM information_schema.SCHEMATA a,information_schema.TABLES b
WHERE a.SCHEMA_NAME=b.TABLE_SCHEMA
AND a.DEFAULT_COLLATION_NAME!=b.TABLE_COLLATION
AND b.TABLE_SCHEMA=’数据库名’

ALTER TABLE 表名 CHANGE 列名 VARCHAR( 100 ) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NULL DEFAULT NULL;

select b.table_name,b.column_name,b.character_set_name,b.collation_name
,CONCAT(‘ALTER TABLE ‘,b.table_name,’ MODIFY ‘,b.column_name,’ ‘,b.DATA_TYPE,'(‘,b.CHARACTER_MAXIMUM_LENGTH,’) ‘,CASE WHEN b.COLUMN_DEFAULT IS NULL THEN ”  ELSE CONCAT(‘DEFAULT \”,b.COLUMN_DEFAULT,‘\”) END,’ COMMENT \”,b.COLUMN_COMMENT,’\’;’) executeSQL
from information_schema.TABLES a,information_schema.COLUMNS b where  b.character_set_name IS NOT NULL and a.TABLE_SCHEMA=b.TABLE_SCHEMA AND a.TABLE_NAME=b.TABLE_NAME
AND a.TABLE_COLLATION!=b.COLLATION_NAME
and a.TABLE_SCHEMA=’数据库名’