数据库现在是latin1_general_ci,我想将排序规则更改为utf8mb4_general_ci。
在PhpMyAdmin中是否有任何设置来更改数据库,表,列的排序规则?而不是一个一个地改变?
数据库现在是latin1_general_ci,我想将排序规则更改为utf8mb4_general_ci。
在PhpMyAdmin中是否有任何设置来更改数据库,表,列的排序规则?而不是一个一个地改变?
当前回答
我使用了以下shell脚本。它将数据库名作为参数,并将所有表转换为另一个字符集和排序规则(由脚本中定义的另一个参数或默认值给出)。
#!/bin/bash
# mycollate.sh <database> [<charset> <collation>]
# changes MySQL/MariaDB charset and collation for one database - all tables and
# all columns in all tables
DB="$1"
CHARSET="$2"
COLL="$3"
[ -n "$DB" ] || exit 1
[ -n "$CHARSET" ] || CHARSET="utf8mb4"
[ -n "$COLL" ] || COLL="utf8mb4_general_ci"
echo $DB
echo "ALTER DATABASE $DB CHARACTER SET $CHARSET COLLATE $COLL;" | mysql
echo "USE $DB; SHOW TABLES;" | mysql -s | (
while read TABLE; do
echo $DB.$TABLE
echo "ALTER TABLE $TABLE CONVERT TO CHARACTER SET $CHARSET COLLATE $COLL;" | mysql $DB
done
)
其他回答
要更改表的排序规则,您可以使用,
ALTER TABLE mytable CONVERT TO CHARACTER SET utf8
若要为整个数据库设置默认排序规则,请执行以下操作
ALTER DATABASE `databasename` DEFAULT CHARACTER SET utf8 COLLATE utf8_bin
否则,
Goto PhpMyAdmin - >操作- >排序。
在这里,您可以找到包含所有现有排序规则的选择框。这样你就可以改变排序规则。在创建新列时,数据库表将遵循这个排序规则。创建新列时不需要选择排序规则。
我在这里读到,你需要手动转换每个表,这是不正确的。下面是一个如何使用存储过程的解决方案:
DELIMITER $$
DROP PROCEDURE IF EXISTS changeCollation$$
-- character_set parameter could be 'utf8'
-- or 'latin1' or any other valid character set
CREATE PROCEDURE changeCollation(IN character_set VARCHAR(255))
BEGIN
DECLARE v_finished INTEGER DEFAULT 0;
DECLARE v_table_name varchar(255) DEFAULT "";
DECLARE v_message varchar(4000) DEFAULT "No records";
-- This will create a cursor that selects each table,
-- where the character set is not the one
-- that is defined in the parameter
DECLARE alter_cursor CURSOR FOR SELECT DISTINCT TABLE_NAME
FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = DATABASE()
AND COLLATION_NAME NOT LIKE CONCAT(character_set, '_%');
-- This handler will set the value v_finished to 1
-- if there are no more rows
DECLARE CONTINUE HANDLER
FOR NOT FOUND SET v_finished = 1;
OPEN alter_cursor;
-- Start a loop to fetch each rows from the cursor
get_table: LOOP
-- Fetch the table names one by one
FETCH alter_cursor INTO v_table_name;
-- If there is no more record, then we have to skip
-- the commands inside the loop
IF v_finished = 1 THEN
LEAVE get_table;
END IF;
IF v_table_name != '' THEN
IF v_message = 'No records' THEN
SET v_message = '';
END IF;
-- This technic makes the trick, it prepares a statement
-- that is based on the v_table_name parameter and it means
-- that this one is different by each iteration inside the loop
SET @s = CONCAT('ALTER TABLE ',v_table_name,
' CONVERT TO CHARACTER SET ', character_set);
PREPARE stmt FROM @s;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
SET v_message = CONCAT('The table ', v_table_name ,
' was changed to the default collation of ', character_set,
'.\n', v_message);
SET v_table_name = '';
END IF;
-- Close the loop and the cursor
END LOOP get_table;
CLOSE alter_cursor;
-- Returns information about the altered tables or 'No records'
SELECT v_message;
END $$
DELIMITER ;
创建过程后,可以简单地调用它:
CALL changeCollation('utf8');
更多细节请阅读这篇博客。
我刚刚编写了一个bash脚本来查找给定数据库中的所有表并隐藏它们(及其列)。
脚本下载地址:https://github.com/Juddling/mysql-charset
下面的查询将生成ALTER查询,将所有表中所有适当列的排序规则更改为某种类型(在下面的示例中为utf8_general_ci)。
SELECT concat
(
'ALTER TABLE ',
t1.TABLE_SCHEMA,
'.',
t1.table_name,
' MODIFY ',
t1.column_name,
' ',
t1.data_type,
'(' ,
CHARACTER_MAXIMUM_LENGTH,
')',
' CHARACTER SET utf8 COLLATE utf8_general_ci;'
)
from
information_schema.columns t1
where
t1.TABLE_SCHEMA like 'you_db_name_goes_here' AND
t1.COLLATION_NAME IS NOT NULL AND
t1.COLLATION_NAME NOT IN ('utf8_general_ci');
你可以运行一个php脚本。
<?php
$con = mysql_connect('localhost','user','password');
if(!$con) { echo "Cannot connect to the database ";die();}
mysql_select_db('dbname');
$result=mysql_query('show tables');
while($tables = mysql_fetch_array($result)) {
foreach ($tables as $key => $value) {
mysql_query("ALTER TABLE $value CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci");
}}
echo "The collation of your database has been successfully changed!";
?>