Using VARRAYs : Varray « Collections « Oracle PL/SQL Tutorial

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Oracle PL/SQL Tutorial » Collections » Varray 
26.2.2.Using VARRAYs

In the Oracle environment, array subscripts start from 1, and not from 0 (as in C and Java).

VARRAYs are of fixed length.

You specify the length of the array when you define it.

Arrays of elements of the same type use sequential numbers as a subscript.

VARRAYS can be used both in PL/SQL and SQL.

You should use VARRAYs when you know the size of your data set and that size is very stable.

declare
  type VarrayType is varray(sizeof ElementType;
...
create or replace type VarrayType is varray(sizeof ElementType;

The size of a VARRAY must be a positive integer and cannot be null.

You cannot create an array of REF CURSORs.

SQL>
SQL> declare
  2      type month_va is varray(13of VARCHAR2(20);
  3      v_month_va month_va;
  4      v_count_nr number;
  5  begin
  6      v_month_va:=month_va('A','B','C','D','E','F','G');
  7      DBMS_OUTPUT.put_line('Length:'||v_month_va.count);
  8
  9      v_month_va.extend;
 10      v_month_va(v_month_va.last):='Null';
 11      DBMS_OUTPUT.put_line('Length:'||v_month_va.count);
 12
 13      for i in v_month_va.first..v_month_va.last
 14      loop
 15          DBMS_OUTPUT.put_line('v_month_va(i)'||v_month_va(i));
 16      end loop;
 17  end;
 18  /
Length:7
Length:8
v_month_va(i): A
v_month_va(i): B
v_month_va(i): C
v_month_va(i): D
v_month_va(i): E
v_month_va(i): F
v_month_va(i): G
v_month_va(i): Null

PL/SQL procedure successfully completed.
26.2.Varray
26.2.1.Creating a Varray Type
26.2.2.Using VARRAYs
26.2.3.Getting Information on Varrays
26.2.4.VARRAY in action
26.2.5.Inside the loop, you are accessing array elements by their subscripts.
26.2.6.Assign value to VARRAY
26.2.7.Defining our type to be a VARRAY with 10 elements, where each element is a varying character string of up to 15 characters.
26.2.8.CREATE TABLE with a VARRAY
26.2.9.Loading a Table with a VARRAY in It: INSERT VALUEs with Constants
26.2.10.Query VARRAY column
26.2.11.Query table with VARRAY type column by column name
26.2.12.Manipulating the VARRAY with The TABLE Function
26.2.13.If aliases are used, they must be used consistently
26.2.14.Manipulating the VARRAY with The VARRAY Self-join
26.2.15.VARRAY of Cursor
26.2.16.The COUNT Function
26.2.17.LAST and COUNT give the same result for VARRAYs.
26.2.18.A procedure that uses EXISTS and LAST
26.2.19.EXISTS and LAST
26.2.20.Using PL/SQL to Create Functions to Access Elements
26.2.21.The CAST function converts an object type (such as a VARRAY) into a common type that can be queried. Oracle 10g automatically converts the VARRAY without the CAST.
26.2.22.One way to make the 'members' behave like an array is first to include the row number in the result set like this:
26.2.23.Then, the individual array element can be extracted with a WHERE filter:
26.2.24.Extracting individual members of a VARRAY may be accomplished using two other functions: THE and VALUE
26.2.25.Column_value is a built-in function/pseudo-variable that is held over from the DBMS_SQL package
26.2.26.Loop through by using the built-in NEXT, PRIOR.
26.2.27.The subscript of the last element is always equal to the size of the array.
26.2.28.Decreasing the Size of an Array
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