Laravel Migration: Foreign key constraint is incorrectly formed

Question

I'm using migrations to change a field to nullable(), using the following code.

$table->integer('recipe_id')->nullable()->change();

But I'm getting the following error.

SQLSTATE[HY000]: General error: 1025 Error on rename of './blackfisk/#sql-2
2d_a' to './blackfisk/preparations' (errno: 150 "Foreign key constraint is
incorrectly formed") (SQL: ALTER TABLE preparations CHANGE recipe_id recipe
_id INT DEFAULT NULL)

I've tried setting the foreign key checks to 0 using

    \DB::statement('SET FOREIGN_KEY_CHECKS=0');

But it's giving the same error. When I try to run the query in Sequel Pro I also get this error, using the following query.

SET FOREIGN_KEY_CHECKS = 0;
ALTER TABLE preparations CHANGE recipe_id recipe_id INT DEFAULT NULL;
SET FOREIGN_KEY_CHECKS = 1;

Any idea If I'm missing something here? Thank you!

https://stackoverflow.com/questions/8434518/mysql-foreign-key-constraint-is-incorrectly-formed-error — Raimondas Kazlauskas, Jul 14 '17 at 08:54
Thanks for your answer, but they are the same field type (INT 10) — Miguel Stevens, Jul 14 '17 at 09:08

score 5 · Accepted Answer · answered Jul 14 '17 at 09:15

5

You should create an unsignedInteger

$table->UnsignedInteger('recipe_id')->nullable()->change();

I hope this helps

answered Jul 14 '17 at 09:15

FULL STACK DEV

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That's it! Thank you! – Miguel Stevens Jul 14 '17 at 09:17
@Notflip i am glad it helped you :). – FULL STACK DEV Jul 14 '17 at 09:28

Laravel Migration: Foreign key constraint is incorrectly formed

1 Answers1