how to use mdf database file in project

Question

hi

i m create a new project that need a database but portable

now i m useing database which is provide by .net i.e serivce based database

but i m using connection string of this database now working in project

but when create setup of my project then database not work and come error

i.e database already exist not open

this is i m using database

i m used this database which show in pic

give some idea or other database expect ms access