The tables are for users to access different places
The design as below:
<user> userid username place (the row define access rights)
<place> placeid placename floor
three places and placeid are 001,002,003 one user and userid is 001 to aceess these three places
<user> userid username place 001 john 001,002,003 <place> placeid placename floor 001 A 1 002 B 2 003 C 3 004 D 4
My question is,
in "user" table, the attribute "place" contains many placeids, and separate by a comma, this design is fine or bad ? It needs to separate the place values from "user" table ?
Using a comma delimited list to do a many to many relationship is bad design. You should use an intermediate table instead:
<user> userid username <place> placeid placename floor <accessrights> userid placeid
Instead of putting "1,2,3" in user.place for userid 001, then, you put three rows in accessrights, all with userid 001 and one with each placeid.