1 pl/sql 集合 處理單列多行數據庫，使用的類型為標量類型
?1） 索引表
? type ename_table_type is table of emp.ename%type
??? index by binary_integer;
? ename_table ename_table_type;
? begin
??? select ename into ename_table(-1) from emp
????? where empno=&no;
??? dbms_output.put_line('雇員名：'||ename_table(-1));
? end;
?
?? set serveroutput no
?? declare
???? type area_table_type is table of number
??????? index by varchar2(10);
???? rea_table area_table_type;
??? begin
??????? area_table('beijing'):=1;
??????? area_table('shanghai'):=2;
??????? area_table('guangzhou'):=3;
??????? dbms_output.put_line(area_table.first);
??????? dbms_output.put_line(area_table.last);
??? end;
???? 2) 嵌套表
????? 索引表類型不能作為累得數據類型使用，但是嵌套表可以作為表類的數據類型使用。
當使用嵌套表元素時，必須先用其構造方法初始化其嵌套表：
?????? a? 在pl/sql 塊中使用嵌套表
??????? declare
????????? type ename_table_type is table of emp.ename%type;
????????? ename_table ename_table_type;
??????? begin
?????????? ename_table:=eanme_table_type('2','2','3');
?????????? select ename into ename table(2) from emp where empno=&no;
?????????? dbms_ouput.put_line(ename_table(2));
??????? end;
????? b 在表中使用嵌套表
??????? create type phone_type is table of varchar2(20);
??????? create table employee(
????????? id number (4),name varchar2(10),sal number(6,2),
????????? phone phone_type
??????? )nested table phone store as phone_table;
?????? -- 為嵌套表插入數據
??????? insert into employee values(2,'scott',200,phone_type('2222','333333'));
?????? －－檢索嵌套表累得數據
??????? set erveroutput on
??????? declare
????????? phone_table phone_type;
??????? begin
????????? select phone into phone_table
????????? from employee where id=1;
????????? for i in 1..phone_table.count loop
??????????? dbms_output.put_line(phone_table(i));
????????? end loop;
??????? end;
?????? -- 更新嵌套表列的數據
???????? delcare
??????????? phone_table phone_type:=('44444','555555');
???????? begin
??????????? update employee set phone=phone_table
??????????? where id=1;
???????? end;
??? 3) 變長數組
????? 在使用varray 時必須指定最大個數，和數據類型,在使用其元素時必須進行初始化
????? type ename_table_type is varray(20) of emp.ename%type;
????? ename_table ename_table_type:=ename_table_type('1','2');
?????
????? -- 在快中使用varray
????? declare
???????? type ename_table_type is varray(20) of emp.ename％type；
???????? ename_table ename_table_type:=ename_table_type('mary');
???????? begin
??????????? select ename into ename_table(1) form emp
?????????????? where empno=$no;
????????? end;
????? --在表列中使用varray
?????? create type phone type is varray(20) of varchar2(20);
?????? create table employee(
???????? id number(4),name varchar2(10),
???????? sal number(6,2),phone phone_type);
??????
???? 3)記錄表
????? 記錄表結合了記錄和集合的優點
??????? declare
????????? type emp_table_type is table of emp%rowtype
????????? index by binary_integer;
??????? emp_table emp_table_type;
??????? begin
????????? select * from into emp_table(1) from emp
????????? where empno=&no;
????????? dbms_output.put_line(emp_table(1).ename);
??????? end;
????? 4)多維集合
?????? 1 多級varray
?????? declare
??????? --define 一維集合
????????? type al_array_type is varray(10) of int;
??????? --定義二維集合
????????? type nal_varray_type is varray(10) of a1_varray_type;
??????? --初始化二維集合
????????? nvl nal_varray_type:=nal_varray_type(
??????????? a1_varray_type(1,2),
??????????? a1_varray_type(2,3)
????????? )
???????? beign
?????????? for i in 1..nal_varray_type.count loop
????????????? for j in 1..a1_array_type.count loop
??????????????? dbms_out.putline(nvl(i)(j));
????????????? end loop;
?????????? end loop;
??????? end;
?????? 2 使用多級嵌套表
??????? table a1_table_type is table of int;
??????? table nvl_table_type is table of a1_table_type;
??????? nvl nvl_table_type:=nvl_table_type(
????????? a1_table_type(1,2),
????????? a1_table_type(2,3)
??????? );
2 集合方法
? 1) exist
?? if ename_table.exists(1) then
??? ename_table(1):='scott';
?? 2) count 返回當前集合變量中的元素總個數
??? ename_table.count
?? 3) limit 返回集合元素的最大個數? 只有varray 有
?? 4)first and last
?????? ename_table.first
?????? ename_table.last
?? 5) prior 和next
??? ename_table.prior(5); －－返回元素5的前一個
??? ename_table.next(5);? --? 后一個
?? 6) extend
??? 使用于varray 和 嵌套表。
??? extend add a null value
??? extend (n) add n null value
??? extend (n,i)add n i value
??? declare
????? type ename_table_type is varray(20) of varchar2(20);
????? ename_table ename_table_type;
??? begin
????? ename_table:=ename_table_type('mary');
????? ename_table.extend(5,1);
????? dbms_output.put_line(ename_table.count);
??? end;
?? 7) trim
?? trim remove one element from the tail of the collection.
?? trim(n) remove n element from the tail of the colleciton.
?? 8)delete
??? delete: delete all the elements
??? delete(n) :delete the nth elements
??? delete(m,n): delete the elements from m to n
3 集合賦值
? 1)將一個集合的數據賦值給另一個集合.clear the destination collectins and set the original collection
?? delcare
??? type name_varray_type is varray(4) of varchar2(10);
??? name_array1 name_varray_type;
??? name_array2 name_varray_type;
?? begin
???? name_array1:=name_varray_type('scott','smith');
???? name_array2:=name_array_type('a','b','c');
???? name_array1:=name_array2;??
?? end;
??
?
? type name_array1_type is varray(4) of varchar2(10);
? type name_array2_type is varray(4) of varchar2(10);
? name_array1 name_array1_type;
? name_array2 name_array2_type;
? 具有相同的數據類型，單具有不同的集合類型不能構賦值
? 2) 給集合賦城null 值
??? 可以使用delete 或 trim
??? 也可以使用 空集合賦給目表集合
??? type name_varray_type is varray(4) of varchar2(10);
??? name_array name_varray_type;
??? name_empty name_varray_type;
???
??? name_array:=name_varray_type('1','2');
??? name_array:=name_empty;
? 3) 使用集合操作賦和比較集合都是10g 的內容，p176 先略過。
4 批量綁定
? 執行單詞sql 操作能傳遞所有集合元素的數據。
? 1 forall 語句
? 用于insert update 和delete操作。在oracle9i 中forall 語句必須具有連續的元素
??? 1) using forall on insert
???? declare
??????? type id_table_type is table of number(6)
??????? index by binary_integer;
??????? type name_table_type is table of varchar2(2)
??????? index by binary integer;
??????? id_table id_table_type;
??????? name_table name_table_type;
????? begin
???????? for i in 1..10 loop
?????????? id_table(i):=i;
?????????? name_table(i):='Name'||to_char(i);
???????? end loop;
???????? forall i in 1..id_table.count
?????????? insert into demo demo values(id_table(i),name_table(i));
????? end;
???? 2)using forall on using update
?????? forall i in 1..id_table.count
?????????? upate demo set name:=name_table(i)
????????????? where id:=id_table(i);
???? 3)using forall on using delete
??????? forall i in 1..id_table.count
??????????? delete from demo where id:=id_table(i);
???? 4) using forall on part of the collection
??????? for i in1..10 loop
????????? id_table(i):=i;
????????? name_table(i):="name"||to_char(i);
??????? end loop;
??????? forall i in 8..10 l
?????????? insert into demo values(id_table(i),name_table(i));
?? 2 bulk collect
???? is fit for select into ,fetch into and dml clause
???? 1) using bulk collect
????? declares??
??????? type emp_table_type is table of emp%rowtype
???????? index by binary_integer;
??????? emp_table emp_table_type;
????? begin
???????? select * bulk collect into emp_table
????????? from emp where deptno=&no;
???????? for i in 1..emp_tablee.count loop
??????????? dbms_output.put_line(emp_table(i).ename);
???????? end loop;
????? 2) 在dml 的返回字句使用bulk collect 字句
???????? declare
????????? type ename_table_type is table of emp.ename%type;
?????????? ename_table ename_table_type;
????????? begin
???????????? deletee from emp where deptno=&no
???????????? returning ename bulk_collect into ename_table;
????????? for i in 1..ename_table.count loop
??????????? dbms_output.put(ename_table(i));
????????? end loop;
??????? end;
????????? end;
????? end;