Mysql Error Code 1701
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Truncate Table With Foreign Key Constraint Sql Server
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Cannot Truncate A Table Referenced In A Foreign Key Constraint Laravel
Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 6.2 million programmers, just like you, helping each other. Join them; cannot truncate a table referenced in a foreign key constraint postgresql it only takes a minute: Sign up How do I truncate tables properly? up vote 17 down vote favorite 9 I'm using datamapper with ruby to store data to certain tables. Several of the tables have very large amounts of information and I want to clear them out when the user 'rebuilds database' (it basically deletes everything and re-calculates data). force truncate table mysql I originally tried Forum.all.destroy and did it for all the different tables, but I noticed some of them just werent deleted from within phpmyadmin. i can only imagine its because of foreign keys. Although I really dont know because my other table which foreing keys was successfully deleted. Not to mention, id rather just 'zero' it out anyway so the keys dont get to extraordinarly large numbers (like key #500,000). I then tried running it with the code below, but it doesnt clear the tables out because of 'foreign key constraints'. I want to force it to work because I know for a fact I'm clearing out all the tables that rely on each other (i'm only not clearing out 2 tables, a settings table and a random storage table, neither of which use foreign keys). So far I have... adapter = DataMapper.repository(:default).adapter adapter.execute('TRUNCATE TABLE `forums`, `dates`, `remarks`'); That would be fine except the mysql syntax is wrong apparently. so thats the first thing I did it 1 by 1 in phpmyadmin and when i did it
ERROR 1701 (42000): Cannot truncate
Set Foreign_key_checks=0 Incorrect Syntax Near '='
a table referenced in a foreign key constraint Explanation Due to that a table http://stackoverflow.com/questions/8641703/how-do-i-truncate-tables-properly is referenced in a foreign key constraint it isn’t possible to truncate the table. Solution It’s possible to disable the foreign key constraint check by adding SET FOREIGN_KEY_CHECKS=0; SET FOREIGN_KEY_CHECKS=0; https://tombevers.me/2013/10/14/how-to-truncate-a-foreign-key-constrained-table/ TRUNCATE table1; TRUNCATE table2; SET FOREIGN_KEY_CHECKS=1; The example works as follow: Disable the foreign key constraint check Truncate table1 Truncate table2 Enable foreign key constraint check again It’s not neccesarry to use SET FOREIGN_KEY_CHECKS=1; to enable the foreign key constraint check again as the setting is only valid during the connection. As soon as you disconnect, the next session will have it set back to 1. Comments Please enable JavaScript to view the comments powered by Disqus. comments powered by Disqus © 2014 Tom Bevers. Powered by Jekyll.
2010 21:38 Reporter: Masahiro Tomita Email Updates: Status: Duplicate Impact on me: None Category:MySQL Server: Documentation Severity:S2 (Serious) Version:5.5.7, https://bugs.mysql.com/bug.php?id=58788 5.5.9 OS:Any Assigned to: Assigned Account Tags: regression Triage: Needs Triage: https://www.quora.com/How-can-I-solve-the-1701-Cannot-truncate-a-table-referenced-in-a-foreign-key-constraint-issue-in-MySQL-when-trying-to-truncate-a-table D2 (Serious) View Add Comment Files Developer Edit Submission View Progress Log Contributions [7 Dec 2010 16:39] Masahiro Tomita Description: On mysqld 5.5.7 'truncate' command cause error 'Cannot truncate a table referenced in a foreign key constraint'. On mysqld 5.5.6 it work fine. How foreign key to repeat: mysql> use test; Database changed mysql> create table t1 (id int, c char(10), primary key (id)) engine innodb; Query OK, 0 rows affected (0.10 sec) mysql> create table t2 (id int, t1 int, foreign key (t1) references t1(id) on delete cascade) engine innodb; Query OK, 0 rows affected (0.24 sec) mysql> truncate t1; foreign key constraint ERROR 1701 (42000): Cannot truncate a table referenced in a foreign key constraint (`test`.`t2`, CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`t1`) REFERENCES `test`.`t1` (`id`)) [7 Dec 2010 16:47] Peter Laursen but DELETE FROM t1; .. works fine. [7 Dec 2010 16:57] Valerii Kravchuk Indeed, we have this error message: macbook-pro:5.5-sec openxs$ bin/mysql -uroot test Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 1 Server version: 5.5.9-debug Source distribution Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> create table t1 (id int, c char(10), primary key (id)) engine innodb;Query OK, 0 rows affected (0.09 sec) mysql> create
foreign key constraint" issue in MySQL when trying to truncate a table?I have two tables: CREATE TABLE IF NOT EXISTS `submissions` ( `submission_id` INT(11) NOT NULL AUTO_INCREMENT) CREATE TABLE IF NOT EXISTS `assessments` ( `assessment_id` INT NOT NULL AUTO_INCREMENT , `submission_id` INT NOT NULL , CONSTRAINT `submission` FOREIGN KEY (`submission_id` ) REFERENCES `submissions` (`submission_id` ) ON DELETE NO ACTION ON UPDATE NO ACTION) When I try to execute TRUNCATE submissions;, I get the error: "_mysql_exceptions.OperationalError: (1701, 'Cannot truncate a table referenced in a foreign key constraint (`assessments`, CONSTRAINT `submission` FOREIGN KEY (`submission_id`) REFERENCES `submissions` (`submission_id`))')" How can I circumvent it?UpdateCancelPromoted by Periscopedata.comData Scientist Pro Tools. Analyze billions of rows in seconds.Get 150x faster queries, beautiful dashboards, and easy-to-share reports. Start a free trial today!Learn More at Periscopedata.comAnswer Wiki1 Answer Franck Dernoncourt, PhD student in AI @ MITWritten 175w agoYou can disable the foreign key check before truncating the table:SET FOREIGN_KEY_CHECKS=0; TRUNCATE submissions; SET FOREIGN_KEY_CHECKS=1; Beware that this might break the integrity of the database.3.5k Views · View UpvotesView More AnswersRelated QuestionsMySQL: #1064 when adding more than 1 constraint on foreign keys?How do you truncate all tables in MySQL?What is the difference between drop and truncate for tables in MySQL?Is it possible to create a foreign key in table B, when I have 3 columns as primary key in table A (with respect to MySQL)?Does a foreign key reference two tables?How do I edit a unique column reference as a foreign key in another table in MySQL?Can we make a table only containing foreign keys to relate other three tables?How do you create a foreign key to link two tables in SQL? I had some problems and it told me that it could not add