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8 kwi 2019 · How do I get a list of all foreign key constraints pointing TO (and FROM) a particular table and/or a particular column from a MySQL database built with MyISAM? This is the same as this InnoDB question, but MyISAM specific for MySQL. Consider the canonical airlines dataset.
Mysql can parse the foreign key syntax for the myisam table type (meaning no error message will be raised if it encounters an fk definition), making migration from other database products or table engines easier because you do not have to edit the create table statements to remove them.
The recommended engine to use foreign keys is InnoDB, and honestly, for 99% of cases InnoDB is better. You can easily change all your database to use InnoDB instead of MyISAM: add default_storage_engine = InnoDB to /etc/mysql/my.cnf (or equivalent)
You are advised to use foreign keys that reference only UNIQUE (including PRIMARY) and NOT NULL keys. For storage engines that do not support foreign keys (such as MyISAM), MySQL Server parses and ignores foreign key specifications.
1.7.2.3 FOREIGN KEY Constraint Differences. The MySQL implementation of foreign key constraints differs from the SQL standard in the following key respects: If there are several rows in the parent table with the same referenced key value, InnoDB performs a foreign key check as if the other parent rows with the same key value do not exist.
MySQL Workbench Manual. Preface and Legal Notices. General Information. Installation. Configuration. Home Screen Tab. Connections in MySQL Workbench. Administrative Tasks. Performance Tools. Database Development. Database Design and Modeling. ... C.6.2 Tutorial: Generating Foreign Keys with MyISAM ...
MySQL FOREIGN KEY Constraint. The FOREIGN KEY constraint is used to prevent actions that would destroy links between tables. A FOREIGN KEY is a field (or collection of fields) in one table, that refers to the PRIMARY KEY in another table.
