CASE STUDY TRIGGERS: BIIT software house wants to maintain a database of its employees, projects assigned to employees and accounts. Database schema is given below.
1- EMPLOYEE( eid, eName, eAge, eCity, eRank, eDep) 2- PROJECT ( pid, pName, pBonusAmout)
3- Project_Allocation ( eid, pid)
4- ACCOUNTS ( eid, Year, Month, Basic_Salary, Project_Bonus)
5- ACCOUNTS_BACKUP( eid, Year, Month, Basic_Salary, Project_Bonus) 6- LOG( srNo, table_name , Date, Time, event, no_of_rows_effected)

Perform following tasks

a- Whenever a record is inserted or updated from ACCOUNTS table, it must also be inserted / updated in ACCOUNT_BACKUP table as well. Do not allow user to delete any record from ACCOUNTS or ACCOUNTS_BACKUP table. On insertion in ACCOUNTS table, Project_Bonus will be calculated by system on the basis of projects assigned to employee.
b- Make sure primary foreign keys must not violate in any table. You must use triggers to apply any type of constraints. All keys are mentioned at the end.
c- LOG table will maintain every activity of Database. Whenever a record is inserted, updated or deleted in database. All data regarding event will be stored in LOG table.