MySQL删除所有表,忽略外键
有没有一种简单的方法可以从MySQL数据库中删除所有表,而忽略其中可能存在的任何外键约束?来自: (请注意,这回答了如何禁用外键检查以便能够以任意顺序删除表。它不回答如何为所有现有表自动生成drop table语句并在单个脚本中执行它们。Jean的回答是这样做的。您可以执行:MySQL删除所有表,忽略外键,mysql,foreign-keys,innodb,sql-drop,Mysql,Foreign Keys,Innodb,Sql Drop,有没有一种简单的方法可以从MySQL数据库中删除所有表,而忽略其中可能存在的任何外键约束?来自: (请注意,这回答了如何禁用外键检查以便能够以任意顺序删除表。它不回答如何为所有现有表自动生成drop table语句并在单个脚本中执行它们。Jean的回答是这样做的。您可以执行: select concat('drop table if exists ', table_name, ' cascade;') from information_schema.tables; 然后运行生成的查询。它们
select concat('drop table if exists ', table_name, ' cascade;')
from information_schema.tables;
然后运行生成的查询。它们将删除当前数据库中的每个表
是有关drop table命令的一些帮助。我发现生成的drop语句集很有用,建议进行以下调整:
拖放表'VIEW\u NAME`
语句更正为拖放视图'VIEW\u NAME`
。
SET FOREIGN_KEY_CHECKS = 0
这将禁用引用完整性检查-因此,当您完成所需的删除操作后,您将需要使用重置密钥检查
SET FOREIGN_KEY_CHECKS = 1
注意:要使用SELECT-easer的输出,mysql-B选项会有所帮助。这里有一个基于光标的解决方案。有点长,但作为一个SQL批处理工作:
DROP PROCEDURE IF EXISTS `drop_all_tables`;
DELIMITER $$
CREATE PROCEDURE `drop_all_tables`()
BEGIN
DECLARE _done INT DEFAULT FALSE;
DECLARE _tableName VARCHAR(255);
DECLARE _cursor CURSOR FOR
SELECT table_name
FROM information_schema.TABLES
WHERE table_schema = SCHEMA();
DECLARE CONTINUE HANDLER FOR NOT FOUND SET _done = TRUE;
OPEN _cursor;
REPEAT FETCH _cursor INTO _tableName;
IF NOT _done THEN
SET @stmt_sql = CONCAT('DROP TABLE ', _tableName);
PREPARE stmt1 FROM @stmt_sql;
EXECUTE stmt1;
DEALLOCATE PREPARE stmt1;
END IF;
UNTIL _done END REPEAT;
CLOSE _cursor;
END$$
DELIMITER ;
call drop_all_tables();
DROP PROCEDURE IF EXISTS `drop_all_tables`;
下面是SurlyDre的存储过程的修改,以便忽略外键:
DROP PROCEDURE IF EXISTS `drop_all_tables`;
DELIMITER $$
CREATE PROCEDURE `drop_all_tables`()
BEGIN
DECLARE _done INT DEFAULT FALSE;
DECLARE _tableName VARCHAR(255);
DECLARE _cursor CURSOR FOR
SELECT table_name
FROM information_schema.TABLES
WHERE table_schema = SCHEMA();
DECLARE CONTINUE HANDLER FOR NOT FOUND SET _done = TRUE;
SET FOREIGN_KEY_CHECKS = 0;
OPEN _cursor;
REPEAT FETCH _cursor INTO _tableName;
IF NOT _done THEN
SET @stmt_sql = CONCAT('DROP TABLE ', _tableName);
PREPARE stmt1 FROM @stmt_sql;
EXECUTE stmt1;
DEALLOCATE PREPARE stmt1;
END IF;
UNTIL _done END REPEAT;
CLOSE _cursor;
SET FOREIGN_KEY_CHECKS = 1;
END$$
DELIMITER ;
call drop_all_tables();
DROP PROCEDURE IF EXISTS `drop_all_tables`;
下面是通过bash脚本自动执行此操作的方法:
host=$1
dbName=$2
user=$3
password=$4
if [ -z "$1" ]
then
host="localhost"
fi
# drop all the tables in the database
for i in `mysql -h$host -u$user -p$password $dbName -e "show tables" | grep -v Tables_in` ; do echo $i && mysql -h$host -u$user -p$password $dbName -e "SET FOREIGN_KEY_CHECKS = 0; drop table $i ; SET FOREIGN_KEY_CHECKS = 1" ; done
我对Dion Truter的答案进行了修改,以使许多表格更容易使用:
SET GROUP_CONCAT_MAX_LEN = 10000000;
SELECT CONCAT('SET FOREIGN_KEY_CHECKS=0;\n',
GROUP_CONCAT(CONCAT('DROP TABLE IF EXISTS `', table_name, '`')
SEPARATOR ';\n'),
';\nSET FOREIGN_KEY_CHECKS=1;')
FROM information_schema.tables
WHERE table_schema = 'SchemaName';
这将在一个字段中返回整个内容,因此您可以复制一次并删除所有表(在Workbench中使用复制字段内容(无引号)
)。如果您有很多表,您可能会在GROUP\u CONCAT()
上遇到一些限制。如果是这样,请增加max len变量(如有必要,请增加max_allowed_packet)。在php中,它的操作非常简单:
$pdo = new PDO('mysql:dbname=YOURDB', 'root', 'root');
$pdo->exec('SET FOREIGN_KEY_CHECKS = 0');
$query = "SELECT concat('DROP TABLE IF EXISTS ', table_name, ';')
FROM information_schema.tables
WHERE table_schema = 'YOURDB'";
foreach($pdo->query($query) as $row) {
$pdo->exec($row[0]);
}
$pdo->exec('SET FOREIGN_KEY_CHECKS = 1');
只需记住将YOURDB更改为数据库的名称,显然是user/pass。From
执行:
use `dbName`; --your db name here
SET FOREIGN_KEY_CHECKS = 0;
SET @tables = NULL;
SET GROUP_CONCAT_MAX_LEN=32768;
SELECT GROUP_CONCAT('`', table_schema, '`.`', table_name, '`') INTO @tables
FROM information_schema.tables
WHERE table_schema = (SELECT DATABASE());
SELECT IFNULL(@tables, '') INTO @tables;
SET @tables = CONCAT('DROP TABLE IF EXISTS ', @tables);
PREPARE stmt FROM @tables;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
SET FOREIGN_KEY_CHECKS = 1;
这将从当前使用的数据库中删除表。您可以使用use
设置当前数据库
或者,Dion接受的答案更简单,除非您需要执行两次,第一次执行查询,第二次执行查询。我提供了一些愚蠢的反勾号来转义数据库和表名中的特殊字符
SELECT CONCAT('DROP TABLE IF EXISTS `', table_schema, '`.`', table_name, '`;')
FROM information_schema.tables
WHERE table_schema = 'dbName'; --your db name here
在类似bash/zsh的Linux shell中:
DATABASE_TO_EMPTY="your_db_name";
{ echo "SET FOREIGN_KEY_CHECKS = 0;" ; \
mysql "$DATABASE_TO_EMPTY" --skip-column-names -e \
"SELECT concat('DROP TABLE IF EXISTS ', table_name, ';') \
FROM information_schema.tables WHERE table_schema = '$DATABASE_TO_EMPTY';";\
} | mysql "$DATABASE_TO_EMPTY"
这将生成命令,然后立即将它们传输到第二个客户端实例,该实例将删除这些表
聪明的一点当然是从这里的其他答案复制过来的——我只是想要一个拷贝和可粘贴的一行(ish)来实际完成OP想要的工作
注意当然,您也必须在这些mysql命令中放入凭据(两次),除非您的安全设置非常低。(或者您可以将mysql命令别名以包含您的凭据。)如果在linux(或任何其他支持管道、echo和grep的系统)中,您只需一行即可完成此操作:
echo "SET FOREIGN_KEY_CHECKS = 0;" > temp.txt; \
mysqldump -u[USER] -p[PASSWORD] --add-drop-table --no-data [DATABASE] | grep ^DROP >> temp.txt; \
echo "SET FOREIGN_KEY_CHECKS = 1;" >> temp.txt; \
mysql -u[USER] -p[PASSWORD] [DATABASE] < temp.txt;
temp.txt\
mysqldump-u[USER]-p[PASSWORD]--添加删除表--无数据[数据库]| grep^drop>>temp.txt\
echo“设置外键检查=1;”>>temp.txt\
mysql-u[USER]-p[PASSWORD][DATABASE]我知道这是一个老问题,但我认为这种方法既快又简单。我在MSSQL服务器上使用以下方法:
if (DB_NAME() = 'YOUR_DATABASE')
begin
while(exists(select 1 from INFORMATION_SCHEMA.TABLE_CONSTRAINTS where CONSTRAINT_TYPE='FOREIGN KEY'))
begin
declare @sql nvarchar(2000)
SELECT TOP 1 @sql=('ALTER TABLE ' + TABLE_SCHEMA + '.[' + TABLE_NAME + '] DROP CONSTRAINT [' + CONSTRAINT_NAME + ']')
FROM information_schema.table_constraints
WHERE CONSTRAINT_TYPE = 'FOREIGN KEY'
exec (@sql)
PRINT @sql
end
while(exists(select 1 from INFORMATION_SCHEMA.TABLES))
begin
declare @sql2 nvarchar(2000)
SELECT TOP 1 @sql2=('DROP TABLE ' + TABLE_SCHEMA + '.[' + TABLE_NAME + ']')
FROM INFORMATION_SCHEMA.TABLES
exec (@sql2)
PRINT @sql2
end
end
else
print('Only run this script on the development server!!!!')
用数据库的名称替换您的_数据库,或者删除整个IF语句(我喜欢增加的安全性)。这是一篇相当古老的帖子,但这里没有一个答案真正回答了我认为的问题,所以我希望我的帖子能帮助人们 我在另一个问题上找到了这个对我来说非常有效的解决方案:
mysql -Nse 'show tables' DB_NAME | while read table; do mysql -e "SET FOREIGN_KEY_CHECKS=0; truncate table \`$table\`" DB_NAME; done
这实际上将清空数据库中的所有表DB_NAME
,而不仅仅显示TRUNCATE
命令行
希望这有帮助 以上每种方法都比这一种方法包含更多的工作
( mysqldump --add-drop-table --no-data -u root -p database | grep 'DROP TABLE' ) > ./drop_all_tables.sql
mysql -u root -p database < ./drop_all_tables.sql
(mysqldump--add drop table--no data-u root-p数据库| grep'drop table')>。/drop_all_tables.sql
mysql-u root-p数据库<./drop_all_tables.sql
目前为止对我来说最好的解决方案
选择数据库->右键单击->任务->生成脚本-将打开生成脚本的向导。在设置脚本选项中选择对象后,单击高级按钮。在“脚本拖放和创建”下选择“脚本拖放”
运行脚本。一行程序从给定数据库中删除所有表:
echo "DATABASE_NAME"| xargs -I{} sh -c "mysql -Nse 'show tables' {}| xargs -I[] mysql -e 'SET FOREIGN_KEY_CHECKS=0; drop table []' {}"
运行此操作将从数据库\u NAME中删除所有表
关于这一点,一件好事是数据库名称只显式写入一次。基于@Dion Truter和@Wade Williams的答案,下面的shell脚本将删除所有表,首先显示它将要运行的内容,并让您有机会使用Ctrl-C中止
#!/bin/bash
DB_HOST=xxx
DB_USERNAME=xxx
DB_PASSWORD=xxx
DB_NAME=xxx
CMD="mysql -sN -h ${DB_HOST} -u ${DB_USERNAME} -p${DB_PASSWORD} ${DB_NAME}"
# Generate the drop statements
TMPFILE=/tmp/drop-${RANDOM}.sql
echo 'SET FOREIGN_KEY_CHECKS = 0;' > ${TMPFILE}
${CMD} $@ >> ${TMPFILE} << ENDD
SELECT concat('DROP TABLE IF EXISTS \`', table_name, '\`;')
FROM information_schema.tables
WHERE table_schema = '${DB_NAME}';
ENDD
echo 'SET FOREIGN_KEY_CHECKS = 1;' >> ${TMPFILE}
# Warn what we are about to do
echo
cat ${TMPFILE}
echo
echo "Press ENTER to proceed (or Ctrl-C to abort)."
read
# Run the SQL
echo "Dropping tables..."
${CMD} $@ < ${TMPFILE}
echo "Exit status is ${?}."
rm ${TMPFILE}
#/bin/bash
DB_HOST=xxx
DB_USERNAME=xxx
DB_PASSWORD=xxx
DB_NAME=xxx
CMD=“mysql-sN-h${DB\u HOST}-u${DB\u USERNAME}-p${DB\u PASSWORD}${DB\u NAME}”
#生成drop语句
TMPFILE=/tmp/drop-${RANDOM}.sql
echo“设置外键检查=0;”>${TMPFILE}
${CMD}$@>${TMPFILE}>${TMPFILE}
#警告我们将要做的事情
回声
cat${TMPFILE}
回声
echo“按ENTER键继续(或按Ctrl-C键中止)。”
阅读
#运行SQL
回音“放下桌子…”
${CMD}$@<${TMPFILE}
echo“退出状态为${?}”
rm${TMPFILE}
总是用谷歌搜索主题
( mysqldump --add-drop-table --no-data -u root -p database | grep 'DROP TABLE' ) > ./drop_all_tables.sql
mysql -u root -p database < ./drop_all_tables.sql
echo "DATABASE_NAME"| xargs -I{} sh -c "mysql -Nse 'show tables' {}| xargs -I[] mysql -e 'SET FOREIGN_KEY_CHECKS=0; drop table []' {}"
#!/bin/bash
DB_HOST=xxx
DB_USERNAME=xxx
DB_PASSWORD=xxx
DB_NAME=xxx
CMD="mysql -sN -h ${DB_HOST} -u ${DB_USERNAME} -p${DB_PASSWORD} ${DB_NAME}"
# Generate the drop statements
TMPFILE=/tmp/drop-${RANDOM}.sql
echo 'SET FOREIGN_KEY_CHECKS = 0;' > ${TMPFILE}
${CMD} $@ >> ${TMPFILE} << ENDD
SELECT concat('DROP TABLE IF EXISTS \`', table_name, '\`;')
FROM information_schema.tables
WHERE table_schema = '${DB_NAME}';
ENDD
echo 'SET FOREIGN_KEY_CHECKS = 1;' >> ${TMPFILE}
# Warn what we are about to do
echo
cat ${TMPFILE}
echo
echo "Press ENTER to proceed (or Ctrl-C to abort)."
read
# Run the SQL
echo "Dropping tables..."
${CMD} $@ < ${TMPFILE}
echo "Exit status is ${?}."
rm ${TMPFILE}
DROP PROCEDURE IF EXISTS `drop_all_tables`;
DELIMITER $$
CREATE PROCEDURE `drop_all_tables`()
BEGIN
DECLARE _done INT DEFAULT FALSE;
DECLARE _tableName VARCHAR(255);
DECLARE _cursor CURSOR FOR
SELECT table_name
FROM information_schema.TABLES
WHERE table_schema = SCHEMA();
DECLARE CONTINUE HANDLER FOR NOT FOUND SET _done = TRUE;
SET FOREIGN_KEY_CHECKS = 0;
OPEN _cursor;
REPEAT FETCH _cursor INTO _tableName;
IF NOT _done THEN
SET @stmt_sql1 = CONCAT('DROP TABLE IF EXISTS ', _tableName);
SET @stmt_sql2 = CONCAT('DROP VIEW IF EXISTS ', _tableName);
PREPARE stmt1 FROM @stmt_sql1;
PREPARE stmt2 FROM @stmt_sql2;
EXECUTE stmt1;
EXECUTE stmt2;
DEALLOCATE PREPARE stmt1;
DEALLOCATE PREPARE stmt2;
END IF;
UNTIL _done END REPEAT;
CLOSE _cursor;
SET FOREIGN_KEY_CHECKS = 1;
END$$
DELIMITER ;
call drop_all_tables();
DROP PROCEDURE IF EXISTS `drop_all_tables`;
echo "SET FOREIGN_KEY_CHECKS = 0;" > ./drop_all_tables.sql
mysqldump --add-drop-table --no-data -u user -p dbname | grep 'DROP TABLE' >> ./drop_all_tables.sql
echo "SET FOREIGN_KEY_CHECKS = 1;" >> ./drop_all_tables.sql
mysql -u user -p dbname < ./drop_all_tables.sql
MYSQL="mysql -h HOST -u USERNAME -pPASSWORD DB_NAME"
$MYSQL -BNe "show tables" | awk '{print "set foreign_key_checks=0; drop table `" $1 "`;"}' | $MYSQL
unset MYSQL
DB="your database name" \
&& mysql $DB < "SET FOREIGN_KEY_CHECKS=0" \
&& mysqldump --add-drop-table --no-data $DB | grep 'DROP TABLE' | grep -Ev "^$" | mysql $DB \
&& mysql $DB < "SET FOREIGN_KEY_CHECKS=1"
1. generate drop query using concat and group_concat.
2. use database
3. disable key constraint check
4. copy the query generated from step 1
5. enable key constraint check
6. run show table
mysql> SYSTEM CLEAR;
mysql> SELECT CONCAT('DROP TABLE IF EXISTS `', GROUP_CONCAT(table_name SEPARATOR '`, `'), '`;') AS dropquery FROM information_schema.tables WHERE table_schema = 'emall_duplicate';
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| dropquery |
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| DROP TABLE IF EXISTS `admin`, `app`, `app_meta_settings`, `commission`, `commission_history`, `coupon`, `email_templates`, `infopages`, `invoice`, `m_pc_xref`, `member`, `merchant`, `message_templates`, `mnotification`, `mshipping_address`, `notification`, `order`, `orderdetail`, `pattributes`, `pbrand`, `pcategory`, `permissions`, `pfeatures`, `pimage`, `preport`, `product`, `product_review`, `pspecification`, `ptechnical_specification`, `pwishlist`, `role_perms`, `roles`, `settings`, `test`, `testanother`, `user_perms`, `user_roles`, `users`, `wishlist`; |
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
mysql> USE emall_duplicate;
Database changed
mysql> SET FOREIGN_KEY_CHECKS = 0; Query OK, 0 rows affected (0.00 sec)
// copy and paste generated query from step 1
mysql> DROP TABLE IF EXISTS `admin`, `app`, `app_meta_settings`, `commission`, `commission_history`, `coupon`, `email_templates`, `infopages`, `invoice`, `m_pc_xref`, `member`, `merchant`, `message_templates`, `mnotification`, `mshipping_address`, `notification`, `order`, `orderdetail`, `pattributes`, `pbrand`, `pcategory`, `permissions`, `pfeatures`, `pimage`, `preport`, `product`, `product_review`, `pspecification`, `ptechnical_specification`, `pwishlist`, `role_perms`, `roles`, `settings`, `test`, `testanother`, `user_perms`, `user_roles`, `users`, `wishlist`;
Query OK, 0 rows affected (0.18 sec)
mysql> SET FOREIGN_KEY_CHECKS = 1;
Query OK, 0 rows affected (0.00 sec)
mysql> SHOW tables;
Empty set (0.01 sec)
mysql>
mysqldump -u [user_name] -p[password] -h [host_name] --add-drop-table --no-data [database_name] | grep ^DROP | mysql -u [user_name] -p[password] -h [host_name] [database_name]
SET FOREIGN_KEY_CHECKS = 0;
SET SESSION group_concat_max_len = 1000000;
SET @TABLES = NULL;
SELECT GROUP_CONCAT('`', table_schema, '`.`', table_name,'`') INTO @TABLES FROM information_schema.tables
WHERE table_schema = 'databaseName';
SET @TABLES = CONCAT('DROP TABLE IF EXISTS ', @TABLES);
PREPARE stmt FROM @TABLES;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
SET SESSION group_concat_max_len = 1024;
SET FOREIGN_KEY_CHECKS = 1