dropForeignKey()

Signature

dropForeignKey() — returns void

Available in: migration Category: Migration Functions

Description

Drops a foreign key constraint from the database Only available in a migration CFC

Parameters

Name	Type	Required	Default	Description
table	string	yes	—	The table name to perform the operation on
keyName	string	yes	—	the name of the key to drop

Examples

// 1. Drop a foreign key constraint by its explicit name
// In the down() function, remove a foreign key added in up()
dropForeignKey(table="orders", keyName="FK_orders_customers");

// 2. Drop a foreign key that was created via addReference()
// addReference() creates keys named FK_<table>_<pluralizedReference>
// So addReference(table="comments", referenceName="post") creates "FK_comments_posts"
dropForeignKey(table="comments", keyName="FK_comments_posts");

// 3. Use inside a migration's down() to reverse an addForeignKey() call
// up() called: addForeignKey(table="profiles", referenceTable="users", column="userId", referenceColumn="id")
// down() reverses it:
dropForeignKey(table="profiles", keyName="FK_profiles_users");