Are you getting the Foreign key violation error. Foreign keys are mean to to enfore relationships between tables. A foreign key column(s) in one table points to PrimaryKey or Unique Index column(s) in another table. The values you are inserting into a Foreign key column should be the same that are in the Perimay key columns.
Ex:- Employee table (EmpID , Name...) - EmpID is the Pkey
EmployeeLeaves table (EmpID,LeaveType,LeaveDate...). EmpID is the Foreign key, it points to EmpId in employee table.