one employee id have only one user name

Question

Hi I want to add one employee id get only one user name . what is the sql query need for this? And if user name get of this employee id sql give message . how it is possible ? please help me.

Pulak deb · Answer

user_login table user_id int(primary key) employee_id nvarchar(50)(foreign key) user_name nvarchar(50) password nvarchar(50) creation_date date employee registration table employee_id int(primary key) faculty_type nvarchar(50) first_name nvarchar(50) last_name nvarchar(50)

Abhay Shanker · Answer

Can you please share your sql table structure.It's simple if you have a primary key column named EmployeeID