oracle 中循环总结
--while循环控制语句  
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declare
  i int := 1;
begin
  while i <= 10 loop
    dbms_output.put_line('当前循环体内i的值:' || i);
    i := i + 1;
  end loop;
end;
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--for循环控制语句 递增                                    
-----------------------
begin
  for i in 1 .. 10 loop
    dbms_output.put_line('当前循环体内i的值:' || i);
  end loop;
end;

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--for循环控制语句 递减  
-----------------------
begin
  for i in reverse 1 .. 10 loop
    dbms_output.put_line('当前循环体内i的值:' || i);
  end loop;
end;

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--嵌套循环和标号  
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declare
  result int := 0;
begin
  <<outer>>
  for i in 1 .. 20 loop
    <<inner>>
    for j in 1 .. 10 loop
      result := i * j;
      dbms_output.put_line('循环时,i=' || i || ',j=' || j || ',result的值:' ||
                           result);
      --当外层循环result值达到200时，跳出整个外层循环  
      exit outer when result = 200;
      --当内层循环result值达到100时，跳出内层循环  
      exit when result = 100;
    end loop inner;
    dbms_output.put_line('end inner ,result的值:' || result);
  end loop outer;
  dbms_output.put_line('end outter ,result的值:' || result);
end;

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--游标 for循环
-----------------------
--数据准备
create table test(a varchar2(100));
insert into test values('test1');
insert into test values('test2');
insert into test values('test3');
commit;
--测试开始
declare
  testRow test%rowtype;
  cursor testRows is
    select * from test;
begin
  for testRow in testRows loop
    dbms_output.put_line(testRow.a ||'  '||
                         testRows%rowcount);
  end loop;
end;
--数据销毁
drop table test;

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--循环插入数据库语句
declare 
    maxrecords constant int:=1000;  
    i int :=1;  
begin 
    for i in 1..maxrecords loop  
        insert into test(a)  
        values(to_char('test'||i));  
        end loop;  
    dbms_output.put_line(' 成功录入数据!');  
    commit;  
end;