| Server IP : 172.67.216.182 / Your IP : 172.69.176.170 Web Server : Apache System : Linux krdc-ubuntu-s-2vcpu-4gb-amd-blr1-01.localdomain 5.15.0-142-generic #152-Ubuntu SMP Mon May 19 10:54:31 UTC 2025 x86_64 User : www ( 1000) PHP Version : 7.4.33 Disable Function : passthru,exec,system,putenv,chroot,chgrp,chown,shell_exec,popen,proc_open,pcntl_exec,ini_alter,ini_restore,dl,openlog,syslog,readlink,symlink,popepassthru,pcntl_alarm,pcntl_fork,pcntl_waitpid,pcntl_wait,pcntl_wifexited,pcntl_wifstopped,pcntl_wifsignaled,pcntl_wifcontinued,pcntl_wexitstatus,pcntl_wtermsig,pcntl_wstopsig,pcntl_signal,pcntl_signal_dispatch,pcntl_get_last_error,pcntl_strerror,pcntl_sigprocmask,pcntl_sigwaitinfo,pcntl_sigtimedwait,pcntl_exec,pcntl_getpriority,pcntl_setpriority,imap_open,apache_setenv MySQL : OFF | cURL : ON | WGET : ON | Perl : ON | Python : OFF | Sudo : ON | Pkexec : ON Directory : /www/server/mysql/src/mysql-test/suite/sys_vars/r/ |
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'#--------------------FN_DYNVARS_032_01-------------------------#' SET @@session.foreign_key_checks = 0; 'connect (con1,localhost,root,,,,)' 'connection con1' SELECT @@session.foreign_key_checks; @@session.foreign_key_checks 1 SET @@session.foreign_key_checks = 1; 'connect (con2,localhost,root,,,,)' 'connection con2' SELECT @@session.foreign_key_checks; @@session.foreign_key_checks 1 '#--------------------FN_DYNVARS_032_02-------------------------#' 'connection con1' DROP TABLE IF EXISTS t1,t2; CREATE TABLE t1(a INT PRIMARY KEY)ENGINE = INNODB; CREATE TABLE t2(a INT PRIMARY KEY,b INT)ENGINE = INNODB; ALTER TABLE t2 ADD CONSTRAINT fk FOREIGN KEY (b) REFERENCES t1 (a); '---Check when foreign_key_checks is enabled---' SET @@session.foreign_key_checks = 1; INSERT INTO t1 values (1),(2),(3); INSERT INTO t2 values (10,1); INSERT INTO t2 values (20,22); ERROR 23000: Cannot add or update a child row: a foreign key constraint fails (`test`.`t2`, CONSTRAINT `fk` FOREIGN KEY (`b`) REFERENCES `t1` (`a`)) '---Check when foreign_key_checks is disabled---' TRUNCATE t1; ERROR 42000: Cannot truncate a table referenced in a foreign key constraint (`test`.`t2`, CONSTRAINT `fk` FOREIGN KEY (`b`) REFERENCES `test`.`t1` (`a`)) SET @@session.foreign_key_checks = 0; TRUNCATE t1; TRUNCATE t2; INSERT INTO t1 values (1),(2),(3); INSERT INTO t2 values (10,1); INSERT INTO t2 values (20,4); 'try enabling foreign_key_checks again'; SET @@session.foreign_key_checks = 1; UPDATE t2 SET b=4 where a=20; 'Check when foreign_key_checks is enabled and FK constraint is re-created' SET @@session.foreign_key_checks = 0; TRUNCATE t2; TRUNCATE t1; INSERT INTO t1 values (1),(2),(3); INSERT INTO t2 values (10,1),(20,4); ALTER TABLE t2 DROP FOREIGN KEY fk; SET @@session.foreign_key_checks = 1; DELETE FROM t2 WHERE b not in (SELECT a from t1); ALTER TABLE t2 ADD CONSTRAINT fk FOREIGN KEY (b) REFERENCES t1 (a); INSERT INTO t2 values (20,2); SELECT * from t2; a b 10 1 20 2 DROP TABLE IF EXISTS t2; DROP TABLE IF EXISTS t1;