SQL: how to fix error #1452?

Question

SQL

I have a table like this.

I want to bind the category column to the categories table.

When I try to do this, I get this error

. How can I fix this?

Answer 1

Make sure that there are no values ​​in the linked field of the child table that are absent in the linked field of the parent table and that both of these fields have exactly the same type.
And for the future - do not paste code or error messages as pictures. Copy text.