One key as foreign key for multiple table - mysql

Question

There are many similar question but this is bit different.
I have one table which has one foreign key that will reference to two tables.
I used below query for testing.
CREATE TABLE users
(
id int NOT NULL,
username varchar(255) NOT NULL,
PRIMARY KEY (id)
);
CREATE TABLE admins
(
id int NOT NULL,
username varchar(255) NOT NULL,
PRIMARY KEY (id)
);
CREATE TABLE info
(
id int NOT NULL,
fullname int NOT NULL,
user_id int,
PRIMARY KEY (id),
FOREIGN KEY (user_id) REFERENCES users(id),
FOREIGN KEY (user_id) REFERENCES admins(id)
);
Above queries works fine.
but when I try to draw model in mysql workbench it create on new field in info table that I don't want. I want user_id should work and show relation as foreign key for users and admins table.
One more thing, am I trying to do that is not well standard? Also suggests a correct way to do it.
Table names used only for example purpose. There is no logic here. I am trying to find solution for one key as foreign key for multiple table and faced issue with mysql work bench.

Answer 1

Try this:
Save your DDL in a file.
Create new model in MySQL Workbench
File > Import > Reverse Engineer MySQL Create Script
Browse to file created in step 1. Ensure that 'Place imported objects on diagram' is selected.
Click 'Execute'
From a data modelling point of view you might be better off specifying a user as an admin by including an extra column on the users table. Hence:
CREATE TABLE users
(
id int NOT NULL,
username varchar(255) NOT NULL,
isAdmin boolean not null default false,
PRIMARY KEY (id)
);
CREATE TABLE info
(
id int NOT NULL,
fullname int NOT NULL,
user_id int,
PRIMARY KEY (id),
FOREIGN KEY (user_id) REFERENCES users(id)
);