下面的MySQL查询本身将生成一个查询，该查询将截断给定数据库中的所有表。它绕过外键:

SELECT CONCAT(
         'SET FOREIGN_KEY_CHECKS=0; ',
         GROUP_CONCAT(dropTableSql SEPARATOR '; '), '; ',
         'SET FOREIGN_KEY_CHECKS=1;'
       ) as dropAllTablesSql
FROM   ( SELECT  Concat('TRUNCATE TABLE ', table_schema, '.', TABLE_NAME) AS dropTableSql
         FROM    INFORMATION_SCHEMA.TABLES
         WHERE   table_schema = 'DATABASE_NAME' ) as queries

<?php
// connect to database
$conn=mysqli_connect("localhost","user","password","database");

// check connection
if (mysqli_connect_errno()) {
  exit('Connect failed: '. mysqli_connect_error());
}

// sql query
$sql =mysqli_query($conn,"TRUNCATE " . TABLE_NAME);


// Print message
if ($sql === TRUE) {
  echo 'data delete successfully';
}
else {
 echo 'Error: '. $conn->error;
}

$conn->close();

?>

这是我用来清除一个表的代码片段。只需更改$conn info和TABLE_NAME。

使用它并形成查询

SELECT Concat('TRUNCATE TABLE ',table_schema,'.',TABLE_NAME, ';') 
FROM INFORMATION_SCHEMA.TABLES where  table_schema in (db1,db2)
INTO OUTFILE '/path/to/file.sql';

现在使用this来使用这个查询

mysql -u username -p </path/to/file.sql

如果你得到这样的错误

ERROR 1701 (42000) at line 3: Cannot truncate a table referenced in a foreign key constraint

最简单的方法是在文件顶部添加这一行

SET FOREIGN_KEY_CHECKS=0;

也就是说，我们不想在遍历这个文件时检查外键约束。

它将截断数据库db1和bd2中的所有表。

我觉得最上面的答案太棒了。但是，当你有一个经过身份验证的MySQL数据库用户时，它就失败了。

这是建立在我链接的顶部答案之上的解决方案。此解决方案安全地处理身份验证，而无需:

为每个表输入密码 担心你的密码泄露到某个地方 对其他MySQL cnf文件(~/.my.cnf)的副作用要了解更多关于这些文件的详细信息，请查看答案底部的参考资料部分。

1. 创建本地。my.cnf文件

vi .temp.my.cnf

[client]
user=<admin_user_goes_here>
password=<admin_password_goes_here>

2. 截断或删除所有表

2.截断所有表(仅为空)

mysql --defaults-extra-file=.temp.my.cnf -Nse 'show tables' <db_name_goes_here> | while read table; do mysql --defaults-extra-file=.temp.my.cnf -e "truncate table $table" <db_name_goes_here>; done

2.B删除所有表(完全删除)

mysql --defaults-extra-file=.temp.my.cnf -Nse 'show tables' <db_name_goes_here> | while read table; do mysql --defaults-extra-file=.temp.my.cnf -e "drop table $table" <db_name_goes_here>; done

3.清理

删除用户密码文件

rm -rf .temp.my.cnf

资源:

https://rtcamp.com/tutorials/mysql/mycnf-preference/ https://dev.mysql.com/doc/refman/8.0/en/option-files.html https://dev.mysql.com/doc/refman/8.0/en/option-file-options.html#option_general_defaults-extra-file

我发现这可以删除数据库中的所有表:

mysqldump -uUSERNAME -pPASSWORD --add-drop-table --no-data DATABASENAME | grep ^DROP | mysql -uUSERNAME -pPASSWORD DATABASENAME

如果您受到托管解决方案的限制(不能删除整个数据库)，则非常有用。

我修改了它来截断表格。mysqldump没有“——add- trunct -table”，所以我做了:

mysqldump -uUSERNAME -pPASSWORD --add-drop-table --no-data DATABASENAME | grep ^DROP | sed -e 's/DROP TABLE IF EXISTS/TRUNCATE TABLE/g' | mysql -uUSERNAME -pPASSWORD DATABASENAME

对我有用 ——edit，修复最后一个命令的错别字

To truncate a table, one must drop the foreign key constraints mapped to the columns in this table from other tables (in fact on all tables in the specific DB/Schema). So, all foreign key constraints must be dropped initially followed by table truncation. Optionally, use the optimize table (in mysql, innodb engine esp) to reclaim the used data space/size to OS after data truncation. Once data truncation is carried out, create the same foreign key constraints again on the same table. See below a script that would generate the script to carry out the above operations. SELECT CONCAT('ALTER TABLE ',TABLE_SCHEMA,'.',TABLE_NAME,' DROP FOREIGN KEY ',CONSTRAINT_NAME,';') FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE CONSTRAINT_TYPE='FOREIGN KEY' AND TABLE_SCHEMA='<TABLE SCHEMA>' UNION SELECT CONCAT('TRUNCATE TABLE ',TABLE_SCHEMA,'.',TABLE_NAME,';') FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA='<TABLE SCHEMA>' AND TABLE_TYPE='BASE TABLE' UNION SELECT CONCAT('OPTIMIZE TABLE ',TABLE_SCHEMA,'.',TABLE_NAME,';') FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA='<TABLE SCHEMA>' AND TABLE_TYPE='BASE TABLE' UNION SELECT CONCAT('ALTER TABLE ',TABLE_SCHEMA,'.',TABLE_NAME,' ADD CONSTRAINT ',CONSTRAINT_NAME,' FOREIGN KEY(',COLUMN_NAME,')',' REFERENCES ',REFERENCED_TABLE_NAME,'(',REFERENCED_COLUMN_NAME,');') FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE WHERE CONSTRAINT_NAME LIKE 'FK%' AND TABLE_SCHEMA='<TABLE SCHEMA>' INTO OUTFILE "C:/DB Truncate.sql" LINES TERMINATED BY '\n';

现在，运行Db Truncate。生成SQL脚本

的好处。 1)回收磁盘空间 2)不需要删除并重新创建具有相同结构的DB/Schema

缺点。 1) FK约束应该是表中的名称，约束名称中包含“FK”。