Collectors

• Varying array• allows you to store repeating attributes of a record in a single row• example: all part numbers can be stored in ORDERS table as a varray

1* create or replace type parts99_va as varray(5) of varchar2(4)SQL> /Type created.

create table orders99_o (ordnumb number(5), orddte date, customer ref customer_ty, parts parts_va)SQL> /Table created.

• inserting records into a varying array

insert into orders99_oselect 12491, to_date('09/02/94', 'mm/dd/yy'), ref(c),parts_va('BT04','BZ66') from customer_o c where c.custnumb=311;

• selecting data from varying arrays

• cannot be queried directly via a select command

Collectors cont’d.• selecting data from varying arrays

set serveroutput on 1 declare 2 cursor order_cursor is 3 select o.customer.custname,o.orddte, o.parts from orders99_o o; 4 order_rec order_cursor%rowtype; 5 begin 6 for order_rec in order_cursor 7 loop 8 dbms_output.put_line('Customer Name: '||order_rec.custname||' '||'Date: '||order_rec.orddte 9 dbms_output.put_line('-----------------------------------------'); 10 for i in 1..order_rec.parts.count 11 loop 12 dbms_output.put_line(order_rec.parts(i)); 13 end loop; 14 end loop; 15* end;SQL> /Customer Name: SALLY ADAMS Date: 02-SEP-94-----------------------------------------AX12Customer Name: DON CHARLES Date: 02-SEP-94-----------------------------------------BT04BZ66

Nested tables

• Limitations of varying arrays• can only contain one column• must declare the maximum number of members at the time of definition• cannot be used in select statement of SQL

• Nested table• a table represented as a column within another table• no limit on the number of entries per row

• Example: create a nested table within ORDERS corresponding to line items (ordlne)• Step 1: Create a type corresponding to ORDLNE

CREATE OR REPLACE TYPE ORDLNE_TY AS OBJECT(PARTNUMB VARCHAR2(4),NUMBORD NUMBER(3),QUOTPRCE NUMBER(7,2))/

• Step 2: Use the above data type as the basis for a nested table

CREATE TYPE ORDLNE_NT AS TABLE OF ORDLNE_TY;/

Nested tables cont’d

• Step 3: Create the ORDERS table using the ORDNLE_NT data type

CREATE TABLE ORDERS(ORDNUMB NUMBER(6),ORDDTE DATE,CUSTOMER REF CUSTOMER_TY,ORDLNE ORDLNE_NT)NESTED TABLE ORDLNE STORE AS ORDLNE_NT_TAB;/

• The above command creates a nested table called ORDLNE_NT_TAB to store line item data within orders • The nested table’s data is stored “out-of-line” with the rest of the table’s data• Although the nested table is stored as a separate table, you cannot access it directly• Inserting data in nested table

INSERT INTO ORDERSSELECT 12489, TO_DATE('09/02/94', 'MM/DD/YY'),REF(C),ORDLNE_NT(ORDLNE_TY('AX12',1,14.95))FROM CUSTOMER_O CWHERE CUSTNUMB=124;

Querying nested tables

• Since a nested table is a column within a table, querying a nested table requires a special key word THE• Example: select all line items of orders placed by DON CHARLES• Step 1: select the nested table column from the main table

select ordlne from orders o where o.customer.custname='DON CHARLES'

• Step 2: enclose this query within the THE function• Step 3: query the nested table’s columns using the clause in Step 2 as the table name in the query’s from clause

1 select nt.partnumb, nt.numbord, nt.quotprce 2* from the (select ordlne from orders o where o.customer.custname='DON CHARLES') NTSQL> /

PART NUMBORD QUOTPRCE---- --------- ---------BT04 1 402.99BZ66 1 311.95