如何将整个MySQL数据库characterset和collat​​ion转换为UTF-8？

Question

如何将整个MySQL数据库字符集转换为UTF-8并将整理转换为UTF-8？

Answer 1

使用ALTER DATABASE和ALTER TABLE命令.

ALTER DATABASE databasename CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
ALTER TABLE tablename CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

或者,如果您仍然使用不支持4字节UTF-8的MySQL 5.5.2或更早版本,请使用utf8而不是utf8mb4:

ALTER DATABASE databasename CHARACTER SET utf8 COLLATE utf8_unicode_ci;
ALTER TABLE tablename CONVERT TO CHARACTER SET utf8 COLLATE utf8_unicode_ci;

Answer 2

1. 做个备份!

2. 然后,您需要在数据库上设置默认字符集.这不会转换现有表,它只为新创建的表设置默认值.

   ALTER DATABASE dbname CHARACTER SET utf8 COLLATE utf8_general_ci;
   

3. 然后,您将需要转换所有现有表及其列的char集.这假设您当前的数据实际上在当前的char集中.如果您的列设置为一个字符集但您的数据确实存储在另一个字符集中,则需要检查MySQL手册以了解如何处理此问题.

   ALTER TABLE tbl_name CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
   

Answer 3

在命令行shell上

如果您是命令行shell,那么您可以非常快速地执行此操作.只需填写"dbname":D

DB="dbname"
(
    echo 'ALTER DATABASE `'"$DB"'` CHARACTER SET utf8 COLLATE utf8_general_ci;'
    mysql "$DB" -e "SHOW TABLES" --batch --skip-column-names \
    | xargs -I{} echo 'ALTER TABLE `'{}'` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;'
) \
| mysql "$DB"

One-liner用于简单复制/粘贴

DB="dbname"; ( echo 'ALTER DATABASE `'"$DB"'` CHARACTER SET utf8 COLLATE utf8_general_ci;'; mysql "$DB" -e "SHOW TABLES" --batch --skip-column-names | xargs -I{} echo 'ALTER TABLE `'{}'` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;' ) | mysql "$DB"

Answer 4

您可以使用以下命令创建sql以更新所有表:

SELECT CONCAT("ALTER TABLE ",TABLE_SCHEMA,".",TABLE_NAME," CHARACTER SET utf8 COLLATE utf8_general_ci;   ",
    "ALTER TABLE ",TABLE_SCHEMA,".",TABLE_NAME," CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;  ") 
    AS alter_sql
FROM information_schema.TABLES
WHERE TABLE_SCHEMA = your_database_name;

捕获输出并运行它.

Arnold Daniels上面的回答更优雅.

Answer 5

在继续之前,请确保您:已完成完整的数据库备份!

第1步:数据库级别更改

• 识别数据库的排序规则和字符集

  SELECT DEFAULT_CHARACTER_SET_NAME, DEFAULT_COLLATION_NAME FROM 
  information_schema.SCHEMATA S
  WHERE schema_name = 'your_database_name'
  AND
  (DEFAULT_CHARACTER_SET_NAME != 'utf8'
      OR
   DEFAULT_COLLATION_NAME not like 'utf8%');
  

• 修复数据库的排序规则

  ALTER DATABASE databasename CHARACTER SET utf8 COLLATE utf8_unicode_ci;
  

第2步:表级更改

• 使用不正确的字符集或排序规则识别数据库表

  SELECT CONCAT(
  'ALTER TABLE ',  table_name, ' CHARACTER SET utf8 COLLATE utf8_general_ci;  ', 
  'ALTER TABLE ',  table_name, ' CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;  ')
  FROM information_schema.TABLES AS T, information_schema.`COLLATION_CHARACTER_SET_APPLICABILITY` AS C
  WHERE C.collation_name = T.table_collation
  AND T.table_schema = 'your_database_name'
  AND
  (C.CHARACTER_SET_NAME != 'utf8'
      OR
   C.COLLATION_NAME not like 'utf8%')
  

• 调整表列的排序规则和字符集

捕获上层sql输出并运行它.(如下)

ALTER TABLE rma CHARACTER SET utf8 COLLATE utf8_general_ci;ALTER TABLE rma CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;  
ALTER TABLE rma_history CHARACTER SET utf8 COLLATE utf8_general_ci;ALTER TABLE rma_history CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;  
ALTER TABLE rma_products CHARACTER SET utf8 COLLATE utf8_general_ci;ALTER TABLE rma_products CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;  
ALTER TABLE rma_report_period CHARACTER SET utf8 COLLATE utf8_general_ci;ALTER TABLE rma_report_period CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;  
ALTER TABLE rma_reservation CHARACTER SET utf8 COLLATE utf8_general_ci;ALTER TABLE rma_reservation CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;  
ALTER TABLE rma_supplier_return CHARACTER SET utf8 COLLATE utf8_general_ci;ALTER TABLE rma_supplier_return CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;  
ALTER TABLE rma_supplier_return_history CHARACTER SET utf8 COLLATE utf8_general_ci;ALTER TABLE rma_supplier_return_history CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;  
ALTER TABLE rma_supplier_return_product CHARACTER SET utf8 COLLATE utf8_general_ci;ALTER TABLE rma_supplier_return_product CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci; 

参考:https://confluence.atlassian.com/display/CONFKB/How+to+Fix+the+Collat​​ion+and+Character+Set+of+a+MySQL+Database

Answer 6

使用HeidiSQL.它是免费的,非常好的数据库工具.

从工具菜单中,输入批量表编辑器

选择完整的数据库或选择要转换的表,

• tick更改默认排序规则:utf8mb4_general_ci
• tick转换为charset:utf8

执行

这将在几秒钟内将完整的数据库从拉丁语转换为utf8.

奇迹般有效 :)

HeidiSQL默认连接为utf8,因此任何特殊字符现在应该被视为字符(æøå),而不是在检查表数据时编码.

从拉丁语转到utf8时真正的陷阱是确保pdo与utf8 charset连接.如果没有,你会将垃圾数据插入到utf8表格并在网页上的所有地方出现问号,让你认为表格数据不是utf8 ...

Answer 7

受@sdfor评论的启发,这是一个完成这项工作的bash脚本

#!/bin/bash

printf "### Converting MySQL character set ###\n\n"

printf "Enter the encoding you want to set: "
read -r CHARSET

# Get the MySQL username
printf "Enter mysql username: "
read -r USERNAME

# Get the MySQL password
printf "Enter mysql password for user %s:" "$USERNAME"
read -rs PASSWORD

DBLIST=( mydatabase1 mydatabase2 )

printf "\n"


for DB in "${DBLIST[@]}"
do
(
    echo 'ALTER DATABASE `'"$DB"'` CHARACTER SET utf8 COLLATE `'"$CHARSET"'`;'
    mysql "$DB" -u"$USERNAME" -p"$PASSWORD" -e "SHOW TABLES" --batch --skip-column-names \
    | xargs -I{} echo 'ALTER TABLE `'{}'` CONVERT TO CHARACTER SET utf8 COLLATE `'"$CHARSET"'`;'
) \
| mysql "$DB" -u"$USERNAME" -p"$PASSWORD"

echo "$DB database done..."
done

echo "### DONE ###"
exit

Answer 8

DELIMITER $$  

CREATE PROCEDURE `databasename`.`update_char_set`()  

BEGIN  
 DECLARE done INT DEFAULT 0;  
 DECLARE t_sql VARCHAR(256);  
 DECLARE tableName VARCHAR(128);  
 DECLARE lists CURSOR FOR SELECT table_name FROM `information_schema`.`TABLES` WHERE table_schema = 'databasename';  
 DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET done = 1;  
 OPEN lists;  
 FETCH lists INTO tableName;  
 REPEAT  
    SET @t_sql = CONCAT('ALTER TABLE ', tableName, ' CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci');  
    PREPARE stmt FROM @t_sql;  
    EXECUTE stmt;  
    DEALLOCATE PREPARE stmt;  
 FETCH lists INTO tableName;  
 UNTIL done END REPEAT;  
 CLOSE lists;  
END$$  

DELIMITER ;  

CALL databasename.update_char_set();