Oracle学习(五)——15天Oracle入门
--集合
--<1>集合.exists(i)是判定集合是否存在第i个元素，存在返回真否则返回假
declare
type mytye is varray(10) of number;
av mytye:= mytye(4,2,5,4,5,0,4,1,8);
ma number:=10;
begin
if av.exists(ma) then
dbms_output.put_line(ma);
end if;
end;
--<2> limit返回集合的最大个数，索引表和嵌套表返回null值
declare
type mytype is table of number(8) index by binary_integer;
va mytype;
begin
dbms_output.put_line(va.limit);
end;
--<3>first 和 last 返回的是第一个或者是最后一个元素的下标。
declare
type mytype is varray(20) of number;
va mytype:=mytype(1,2,3,4,5,6,7,8,9,10);
begin
dbms_output.put_line(va.first);
dbms_output.put_line(va.last);
end; --注意其返回是下标
--<4> priop 和 next 返回的是无素的上一个或者下一个元素的下标，其返回的同样是下标
declare
type mytype is varray(20) of varchar2(20);
va mytype;
begin
va:=mytype('a','b','c','d','e','f','g','h','i','j','k');
dbms_output.put_line(va.prior(2));
end;
--<5>trim 从尾部删除元素, trim从尾部删除一个, trim(n)从尾部删除n个
declare
type mytype is varray(20) of varchar2(20);
va mytype;
begin
va:=mytype('a','b','c','d','e','f','g','h','i','j','k');
va.trim(3);
for i in 1..va.count loop
dbms_output.put_line(va(i));
end loop;
end;
--<6> delete 同样是删除尾部元素，delete 删除全部元素，delete(n),删 除集合第n个元素
create table test
( tid number(10), tname varchar2(10))
--在forall语句中使用部分集合元素
declare
type my is table of number(6) index by binary_integer;
type my2 is table of varchar2(10) index by binary_integer;
va1 my;
va2 my2;
start_time number(10);
end_time number(10);
begin
for i in 1 .. 50 loop
va1(i) := i;
va2(i) := 'name';
end loop;
forall i in 40 .. 50
insert into test values (va1(i), va2(i));
end;
select * from test
drop table test
declare
type my is table of number(6);
va1 my:=my(41,null,43,null,45);
begin
forall i in indices of va1 --删去在这个处的索引
delete from test where tid=va1(i);
end;
declare
type my is table of number(10);
va1 my:=my(41,null,43,null,45);
begin
forall i in values of va1
delete from test where tid=va1(i); --删去在这个处的索引
end;
--Bulk collect 子句用于取得批量数据 ,它只适用于selete into语句,fetch into语句 和DML返回子句
declare
type my is table of emp%rowtype index by binary_integer;
va my;
begin
select * bulk collect into va from emp;--返回的是一列数据
for i in 1..va.count loop
dbms_output.put_line(va(i).ename|| va(i).job||va(i).sal);
end loop;
end;
create table emp as select * from scott.emp
select * from emp
--在DML的返回子句中使用bulk collect子句
declare
type my is table of emp%rowtype ;
va my;
begin
delete from emp where deptno =20
returning empno,ename,job,mgr,hiredate,sal,comm,deptno bulk collect into va;--return语句后必须要全部列出列名不能用*代替
for i in 1..va.count loop
dbms_output.put_line(va(i).ename||va(i).job);
end loop;
end;
select * from emp