please any help for this SQL query

*) Display employee names and dependent information. Also include those employees that dont have any dependent. *) Find out the employee names and number of years worked along with their department names in descending order by number of years (up to two decimal points) worked. *) Who works in the same department in which Heng Lee works? Display first name, last name and positon. Excluce Heng Lee as part of the output. *) Which department has more employees than department 20? Display the department id and number of employee in the department. *) Which employees are working in the company shorter than amin Muhammad? Display names and hire dates. *) Find employees with maximum salary in their own department with the use of correlated subquery. *) Find employee names whose last name start either with a D or C and second last character of first name is either an e or a n. *) List pair of employee names who are having the same qualification order by qualification id

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(The SQL table structure)

drop table emplevel cascade constraints;

drop table position cascade constraints;

drop table dept cascade constraints;

drop table employee cascade constraints;

drop table qualification cascade constraints;

drop table dependent cascade constraints;

CREATE TABLE emplevel

(SalaryLevel CHAR(1),

LowSalary NUMBER (6),

HighSalary NUMBER (6),

CONSTRAINT emplevel_levelno_pk PRIMARY KEY (SalaryLevel));

CREATE TABLE position

(PositionId CHAR (1),

PosDesc VARCHAR2 (10),

CONSTRAINT position_positionid_pk PRIMARY KEY (PositionId));

CREATE TABLE qualification

(QualId CHAR (1),

QualDesc VARCHAR2 (20),

CONSTRAINT qualification_qualid_pk PRIMARY KEY (QualId));

CREATE TABLE dept

(DeptId NUMBER (2),

DeptName VARCHAR2 (12) NOT NULL,

Location VARCHAR2 (20),

EmployeeId NUMBER (3),

CONSTRAINT dept_deptid_pk PRIMARY KEY (DeptId));

CREATE TABLE employee

(EmployeeId NUMBER (3),

Lname VARCHAR2 (15) CONSTRAINT employee_lname_nn NOT NULL,

Fname VARCHAR2 (15) CONSTRAINT employee_fname_nn NOT NULL,

PositionId CHAR (1),

Supervisor NUMBER (3),

HireDate DATE,

Salary NUMBER (6),

Commission NUMBER (5),

DeptId NUMBER (2) NOT NULL,

QualId CHAR (1),

CONSTRAINT employee_employeeid_pk

PRIMARY KEY (EmployeeId),

CONSTRAINT employee_positionid_fk FOREIGN KEY (PositionId)

REFERENCES position (PositionId),

CONSTRAINT employee_deptid_fk FOREIGN KEY (DeptId)

REFERENCES dept (DeptId),

CONSTRAINT employee_qualid_fk FOREIGN KEY (QualId)

REFERENCES qualification (QualId));

CREATE TABLE dependent

(EmployeeId NUMBER (3),

DependentId NUMBER (1),

DepDOB DATE,

Relation VARCHAR2 (8),

CONSTRAINT dependent_empiddepid_pk PRIMARY KEY (EmployeeId, DependentId),

CONSTRAINT dependent_employeeid_fk FOREIGN KEY (EmployeeId)

REFERENCES employee (EmployeeId));

INSERT INTO emplevel VALUES ('A', 1, 25000);

INSERT INTO emplevel VALUES ('B', 25001, 50000);

INSERT INTO emplevel VALUES ('C', 50001, 100000);

INSERT INTO emplevel VALUES ('D', 100001, 500000);

INSERT INTO position VALUES ('P', 'President');

INSERT INTO position VALUES ('M', 'Manager');

INSERT INTO position VALUES ('R', 'Programmer');

INSERT INTO position VALUES ('A', 'Accountant');

INSERT INTO position VALUES ('S', 'Salesman');

INSERT INTO qualification VALUES ('D', 'Doctorate');

INSERT INTO qualification VALUES ('M', 'Masters');

INSERT INTO qualification VALUES ('B', 'Bachelors');

INSERT INTO qualification VALUES ('H', 'Higher Diploma');

INSERT INTO qualification VALUES ('C', 'Certificate');

INSERT INTO dept VALUES (10, 'Finance', 'Kuala Lumpur', 123);

INSERT INTO dept VALUES (20, 'InfoSys', 'Cyberjaya', 443);

INSERT INTO dept VALUES (30, 'Sales', 'Subang Jaya', 135);

INSERT INTO dept VALUES (40, 'Marketing', 'Petaling Jaya', 246);

INSERT INTO employee VALUES (111, 'Lee', 'Heng', 'P', NULL,

TO_DATE ('04/15/1966', 'mm/dd/yyyy'), 265000, 35000, 10, 'D');

INSERT INTO employee VALUES (246, 'Krisna', 'Ananda', 'M', 111,

TO_DATE ('05/19/1967', 'mm/dd/yyyy'), 150000, 10000, 40, 'M');

INSERT INTO employee VALUES (231, 'Andiapan', 'Nagapan', 'A', 246,

TO_DATE ('06/13/1980', 'mm/dd/yyyy'), 85000, 8500, 40, 'B');

INSERT INTO employee VALUES (123, 'Raja', 'Vellu', 'M', 111,

TO_DATE ('12/02/1991', 'mm/dd/yyyy'), 105000, NULL, 10, 'M');

INSERT INTO employee VALUES (443, 'Ali', 'Fatimah', 'M', 111,

TO_DATE ('03/15/1995', 'mm/dd/yyyy'), 80000, 20000, 20, 'B');

INSERT INTO employee VALUES (433, 'Muhammad', 'Amin', 'R', 443,

TO_DATE ('05/10/1997', 'mm/dd/yyyy'), 66500, NULL, 20, 'H');

INSERT INTO employee VALUES (323, 'Salah', 'Kamuingat', 'R', 443,

TO_DATE ('01/01/1995', 'mm/dd/yyyy'), 76500, NULL, 20, 'B');

INSERT INTO employee VALUES (200, 'Seow', 'Jing', 'S', 135,

TO_DATE ('01/03/00', 'mm/dd/yy'), 24500, 3000, 30, NULL);

INSERT INTO employee VALUES (135, 'Chan', 'Hong', 'M', 111,

TO_DATE ('02/29/1996', 'mm/dd/yyyy'), 45000, 5000, 30, 'C');

INSERT INTO employee VALUES (322, 'Chen', 'Derek', 'A', 123,

TO_DATE ('08/15/1999', 'mm/dd/yyyy'), 75000, NULL, 10, 'B');

INSERT INTO employee VALUES (128, 'Din', 'Dong', 'R', 135,

TO_DATE ('02/29/1996', 'mm/dd/yyyy'), 38000, 8000, 30, 'C');

INSERT INTO employee VALUES (248, 'Chow', 'Fatt', 'A', 135,

TO_DATE ('08/15/1999', 'mm/dd/yyyy'), 30000, NULL, 10, 'B');

INSERT INTO dependent VALUES (443, 1, TO_DATE ('09/28/1968', 'mm/dd/yyyy'),

'Spouse');

INSERT INTO dependent VALUES (443, 2, TO_DATE ('10/14/1988', 'mm/dd/yyyy'),

'Son');

INSERT INTO dependent VALUES (200, 1, TO_DATE ('06/10/1976', 'mm/dd/yyyy'),

'Spouse');

INSERT INTO dependent VALUES (322, 1, TO_DATE ('02/04/1975', 'mm/dd/yyyy'),

'Spouse');

INSERT INTO dependent VALUES (322, 2, TO_DATE ('08/23/1997', 'mm/dd/yyyy'),

'Son');

INSERT INTO dependent VALUES (322, 3, TO_DATE ('07/10/1999', 'mm/dd/yyyy'),

'Daughter');

INSERT INTO dependent VALUES (111, 1, TO_DATE ('12/12/1965', 'mm/dd/yyyy'),

'Spouse');

ALTER TABLE dept

ADD CONSTRAINT dept_employeeid_fk FOREIGN KEY(EmployeeId)

REFERENCES employee(EmployeeId);

ALTER TABLE employee

ADD CONSTRAINT employee_supervisor_fk FOREIGN KEY(Supervisor)

REFERENCES employee(EmployeeId);

commit;