--****Creating of PO Header Table ******* 
create table po_num
(po_num number,
 po_header_id number)

--*****Inserting*** 
insert into po_num
values
(101,1001)        

insert into po_num
values
(102,1002)

--****Creating of PO Line Table *******
create table po_lines
(line_num number,
 po_header_id number,
 po_line_id number,
 item varchar2(100))
 
--*****Inserting*** 
insert into po_lines
values
(1,1001,1111,'Pen')

insert into po_lines
values
(2,1001,1112,'Mouse')

insert into po_lines
values
(3,1001,1113,'KeyBoard')

insert into po_lines
values
(4,1001,1114,'Book')

insert into po_lines
values
(5,1001,1115,'Desktop')

insert into po_lines
values
(6,1001,1116,'Wire')

insert into po_lines
values
(7,1001,1117,'Laptop')

--****Creating Tax Details Table *******

create table tax_table
(tax_name varchar2(100),
 tax_descr varchar2(100),
 po_header_id number,
 po_line_id number) 
 
insert into tax_table
values
('A','Tax for A ',1001,1111) 

insert into tax_table
values
('B','Tax for B ',1001,1111)

insert into tax_table
values
('C','Tax for C ',1001,1111)

insert into tax_table
values
('D','Tax for D ',1001,1111)

insert into tax_table
values
('A','Tax for A ',1001,1112) 

insert into tax_table
values
('B','Tax for B ',1001,1112)

insert into tax_table
values
('C','Tax for C ',1001,1112)

insert into tax_table
values
('D','Tax for D ',1001,1112)

insert into tax_table
values
('A','Tax for A ',1001,1113) 

insert into tax_table
values
('B','Tax for B ',1001,1113)

insert into tax_table
values
('C','Tax for C ',1001,1113)

insert into tax_table
values
('D','Tax for D ',1001,1113)

insert into tax_table
values
('C','Tax for C ',1001,1114)

insert into tax_table
values
('D','Tax for D ',1001,1114)

insert into tax_table
values
('e','Tax for e ',1001,1115)

insert into tax_table
values
('C','Tax for C ',1001,1116)

insert into tax_table
values
('D','Tax for D ',1001,1116)

insert into tax_table
values
('e','Tax for e ',1001,1117)

--***********For Po Num - 102 ********
insert into po_lines
values
(1,1002,2221,'xxxx')

insert into po_lines
values
(2,1002,2222,'yyyy')

insert into po_lines
values
(3,1002,2223,'zzzz')

insert into po_lines
values
(4,1002,2224,'hhhh')

insert into tax_table
values
('A','Tax for A ',1002,2221) 

insert into tax_table
values
('B','Tax for B ',1002,2221)

insert into tax_table
values
('A','Tax for A ',1002,2222) 

insert into tax_table
values
('B','Tax for B ',1002,2222)

insert into tax_table
values
('A','Tax for A ',1002,2223) 

insert into tax_table
values
('B','Tax for B ',1002,2223)

insert into tax_table
values
('A','Tax for A ',1002,2224) 

insert into tax_table
values
('B','Tax for B ',1002,2224)

--*** Select statement ---

select po_num,po_header_id from po_num
where po_num = 101

select  * from po_lines
where po_header_id = 1001

select  * from tax_table
where po_line_id = 1111