是否存在在一次操作中截断数据库中所有表的查询(命令)?我想知道我是否可以用一个查询做到这一点。


当前回答

mysqldump -u root -p --no-data dbname > schema.sql
mysqldump -u root -p drop dbname
mysqldump -u root -p < schema.sql

其他回答

删除(即删除表格)

mysql -Nse 'show tables' DATABASE_NAME | while read table; do mysql -e "drop table $table" DATABASE_NAME; done

截断(即空表)

mysql -Nse 'show tables' DATABASE_NAME | while read table; do mysql -e "truncate table $table" DATABASE_NAME; done

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

TB=$( mysql -Bse "show tables from DATABASE" );
for i in ${TB};
    do echo "Truncating table ${i}";
    mysql -e "set foreign_key_checks=0; set unique_checks=0;truncate table DATABASE.${i}; set foreign_key_checks=1; set unique_checks=1";
    sleep 1;
done

--

大卫,

感谢您花时间格式化代码,但这是它应该如何应用。

库尔特

在UNIX或Linux机器上:

确保您处于bash shell中。从命令行运行这些命令,如下所示。

注意:

我将凭据存储在~/.my.cnf文件中,因此不需要在命令行上提供凭据。

注意:

CPM是数据库名称

我只展示了来自每个命令的结果的一小部分示例。

找到你的外键约束:

klarsen@Chaos:~$ mysql -Bse "select concat(table_name, ' depends on ', referenced_table_name)
             from information_schema.referential_constraints
             where constraint_schema = 'cpm'
             order by referenced_table_name"

Approval_external_system依赖于approval_request 地址视客户而定 Customer_identification取决于客户 External_id取决于客户 凭证取决于客户 Email_address取决于客户 Approval_request取决于客户 Customer_status取决于客户 Customer_image取决于客户

列出表和行数:

klarsen@Chaos:~$ mysql -Bse "SELECT table_name, table_rows FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = 'cpm'" | cat -n

 1  address 297
 2  approval_external_system    0
 3  approval_request    0
 4  country 189
 5  credential  468
 6  customer    6776
 7  customer_identification 5631
 8  customer_image  2
 9  customer_status 13639

截断你的表:

klarsen@Chaos:~$ TB=$( mysql -Bse "show tables from cpm" ); for i in ${TB}; do echo "Truncating table ${i}"; mysql -e "set foreign_key_checks=0; set unique_checks=0;truncate table cpm.${i}; set foreign_key_checks=1; set unique_checks=1"; sleep 1; done

截断表地址 截断表approval_external_system 截断表approval_request 截断表国家 截断表凭据 截断表客户 截断表customer_identification 截断表customer_image 截断表customer_status

验证它是否有效:

klarsen@Chaos:~$ mysql -Bse "SELECT table_name, table_rows FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = 'cpm'" | cat -n

 1  address 0
 2  approval_external_system    0
 3  approval_request    0
 4  country 0
 5  credential  0
 6  customer    0
 7  customer_identification 0
 8  customer_image  0
 9  customer_status 0
10  email_address   0

在Windows机器上:

注意:

CPM是数据库名称

C:\>for /F "tokens=*" %a IN ('mysql -Bse "show tables" cpm') do mysql -e "set foreign_key_checks=0; set unique_checks=0; truncate table %a; foreign_key_checks=1; set unique_checks=1" cpm

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”。

下面是一个截断本地数据库中所有表的过程。

如果它不起作用,请告诉我,我会删除这个答案。

未测试的

CREATE PROCEDURE truncate_all_tables()
BEGIN

   -- Declare local variables
   DECLARE done BOOLEAN DEFAULT 0;
   DECLARE cmd VARCHAR(2000);

   -- Declare the cursor
   DECLARE cmds CURSOR
   FOR
   SELECT CONCAT('TRUNCATE TABLE ', TABLE_NAME) FROM INFORMATION_SCHEMA.TABLES;

   -- Declare continue handler
   DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET done=1;

   -- Open the cursor
   OPEN cmds;

   -- Loop through all rows
   REPEAT

      -- Get order number
      FETCH cmds INTO cmd;

      -- Execute the command
      PREPARE stmt FROM cmd;
      EXECUTE stmt;
      DROP PREPARE stmt;

   -- End of loop
   UNTIL done END REPEAT;

   -- Close the cursor
   CLOSE cmds;

END;