How to change the field type in mysql?

There is a table with primary id tynyint was not enough id.
When you try to change the field to smallint swears on errno 150 is a foreign key error.
I do not intend for anything to change keys or id to rewrite, just the ability to add rooms on the right.
How to change the field type in this case?
June 5th 19 at 21:33
2 answers
June 5th 19 at 21:35
Once this field is used somewhere in other tables as a foreign key, then there is also the need to change its type.
June 5th 19 at 21:37
a foreign key connects fields of the same type

need:
1) the delete key
2) change the field type
3) change the type of the bound field
4) create a key

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