| Server IP : 88.99.149.37 / Your IP : 216.73.216.141 Web Server : nginx/1.31.2 System : Linux server-88-99-149-37 6.12.0-124.56.5.el10_1.x86_64 #1 SMP PREEMPT_DYNAMIC Fri May 15 06:12:08 EDT 2026 x86_64 User : muralimurth ( 1015) PHP Version : 8.4.23 Disable Function : exec,system,passthru,shell_exec,proc_close,proc_open,dl,popen,show_source,posix_kill,posix_mkfifo,posix_getpwuid,posix_setpgid,posix_setsid,posix_setuid,posix_setgid,posix_seteuid,posix_setegid,posix_uname MySQL : OFF | cURL : ON | WGET : ON | Perl : ON | Python : OFF | Sudo : ON | Pkexec : ON Directory : /usr/local/mysql/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 disconnect con2; '#--------------------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;