you can make this:
[DataContract]
public class Employee
{
[DataMember]
public int Id;
[DataMember]
public string Name;
[DataMember]
public decimal Salary;
}
[ServiceContract]
public interface IService
{
[OperationContract]
void AddEmployee(Employee employee);
}
Implement method AddEmployee in server and just call it from client. Client should now nothing about SQL, otherwise its no point to make WCF.
As for insert phase implementation it has nothing to do with WCF. Refer to LinqToSQL
using-linq-to-sql-part-1 or
Simple-LINQ-to-SQL-in-C
If you have DataContext then you can do following:
MyDataCotext db = new MyDataCotext();
EmployeeRecord emp = new EmployeeRecord();
emp.Id = Employee.Id
emp.Name = Employee.Name
emp.Salary = Employee.Salary
db.EmployeeRecords.Add(emp);
db.SubmitChanges();