MySQL & FK constraints

Is there any point in defining FK constraints in MyISAM? MyISAM doesn't enforce referential inte开发者_如何转开发grity, right? So maybe there is no point to FK constraints.

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Although MySQL parses and ignores them on MyISAM tables, I think you should write them for three reasons.

• Preparation: Your code will be ready when MyISAM gets there.
• Documentation: Everybody will know what you intended. Much better than trying to figure out where foreign keys are supposed to go a year from now.
• Insurance: If MyISAM fails you, you can move directly to InnoDB tables.

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http://dev.mysql.com/doc/refman/5.0/en/ansi-diff-foreign-keys.html

At the end of second column:

At a later stage, foreign key constraints will be implemented for MyISAM tables as well.

apparently in mysql 5.0 'latter stage' has not come yet
constraints are needed as an additional validation