Mysql on delete com Feb 1, 2016 · 如果父表试图update或者delete任何子 表中存在或匹配的外键值，最终动作取决于外键约束定义中的on update和on delete选项。innodb支持5种不同的动作，如果没有指定on delete或者on update，默认的动作为restrict: 1. > SHOW CREATE TABLE tbl_name Create Table: CREATE TABLE `tbl_name` ( `id` int(11) DEFAULT NULL, `foo_id` int(11) DEFAULT NULL, CONSTRAINT `foo_ibfk_1` FOREIGN KEY (`foo_id`) ) Aug 5, 2024 · MySQL BEFORE DELETE trigger is a powerful tool that automatically performs specific actions before an DELETE operation is executed on a table. Dec 30, 2016 · I have table "A" in MySQL. For example, consider a table colors with rows blue, purple, yellow, and a table products with a product_color column, being FK'ed to the colors table. 外键约束. id; END Dont forget the ";" on the delete query. update cascade) engine=innodb. The TRUNCATE TABLE is faster than DELETE Statement When the DELETE statement is executed, it removes the data as well as returns the number of the rows that have been deleted The speed of delete operations may also be affected by factors discussed in Section 8. MySQL supports ON UPDATE and ON DELETE foreign key references in CREATE TABLE and ALTER TABLE statements. on delete . apisjfqhouahhyjjdrqnsbwdpujanobzzvzqlpceafnzgkkryzlywzgjdzaouwxfrtahmcyz