consists of one or more columns in a table that can be used together to identify a single row in A another table. A. Primary Key B. Compound Key C. Foreign Key D. Surrogate Key

when would a database designer need to createin a artifical key? a)when no simple or composite primary key exist in a table b) When the primary key is identical to the supertype primary key. c) When there is no single columns key avialable d) When there is an ISA relationship in a table

Write a SQL statement to create a table job_history including columns employee_id, start_date, end_date, job_id and department_id and make sure that, the employee_id column does not contain any duplicate value at the time of insertion and the foreign key column job_id contain only those values which are exists in the jobs table. Field EMPLOYEE_ID START_DATE END DATE JOB_ID DEPARTMENT_ID Type Decimal(6,0) Date Date Varchar(10) Decimal(4,0) Null No No No No Yes Key pk fk Default Extra Null Null Null Null Null

A table is divided into databases. a. True b. False