Oracle ----- familiar with basic usage

Oracle ----- familiar with the basic use of oracle databases, do not come! 1. create a table employee with the following fields: Id number (4), First_Name varchar2 (20), last_Name varchar2 (20), mgrid NUMBER (4), Job varchar2 (20 ), salary number (7,2) [SQL] create table employee (Id number (4), First_Name varchar2 (20), last_Name varchar2 (20), mgrid NUMBER (4 ), job varchar2 (20), Salary number (7,2); 2. insert the following data into the table, submit, and query the data; ID FIRST_NAME LAST_NAME mgrid salary 1 Rose Taylor 4 1500 2 Matha Jones 4 2200 3 Donna Noble 4 1300 4 Doctor Who 3500 5 Jack Harkness 1 3000 [SQL] insert into employee values (1, 'Rose ', 'Count', 4, null, 1500); insert into employee values (2, 'matha', 'Jones', 4, null, 2200 ); insert into employee values (3, 'dona', 'noble ', 4, null, 1300); insert into employee values (4, 'Doctor', 'who', null, null, 3500); insert into employee values (5, 'jack', 'hark', 1, null, 3000); 3. change last_name of employee 3 to "Tate", submit and query the data. [SQL] update employee set last_name = 'tate' where id = 3; commit; select * from employee; 4. change the salary of all employees whose salaries are less than 5000 to 5000 (do not submit), set the storage point, and query data. [SQL] update employee set salary = 5000 where salary <5000; savepoint a; select * from employee; 5. delete all data in the employee table (do not submit) and query data; // delete from + Table name = delete + Table name [SQL] delete employee where 2 = 2; select * from employee; 6. roll back to the storage point set in question 4 to query data. [SQL] rollback to a; select * from employee; 7. delete all data in the table employee, submit the data, and query the data. [SQL] truncate table employee;