Oracle SQL Developer

The management of Just Lee Books has approved implementing a new commission policy and benefits plan for the account managers. The following changes need to be made to the existing database:

1. Two new columns must be added to the ACCTMANAGER table: one to indicate the commission classification assigned to each employee and another to contain each employees benefit code. The commission classification column should be able to store integers up to a maximum value of 999 and be named Commission_ID. The value of the Commission_ID column should be set to a value of 11 automatically if no value is provided when a row is added. The benefits code column should also accommodate integer values up to a maximum of 999 and be named Benefit_ID.
2. A new table, COMMRATE, must be created to store the commission rate schedule and must contain the following columns:
   1. Commission_id: a numeric column similar to the one added to the ACCTMANAGER table.
   2. Commission_Rank: a character field that can store a rank name allowing up to 15 characters
   3. Commission_Rate: a numeric field that can store two decimal digits such as .01 or .03
3. A new table, BENEFITS, must be created to store the available benefit plan options and must contain the following columns:
   1. Benefit_ID: a numeric column similar to the one added to the ACCTMANAGER table
   2. Benefit_plan: a character field that can store a single character value
   3. Benedit_provider: a numeric field that can store a three digit integer
   4. Is_Active: a character field that can hold a value of Y or N.