PL/SQL流程控制语句详解-优快云博客

本文链接：https://blog.youkuaiyun.com/iteye_19528/article/details/82212312

条件语句：

if...then...else语句：

declare
  l_num number := &num;
  begin
      if  l_num = 1 then
        dbms_output.put_line(1);
      elsif l_num = 2 then
        dbms_output.put_line(2);
      else
        dbms_output.put_line('other');
      end if;
  end;

case语句：

declare
  l_num number := &num;
  begin
      case l_num
        when 1 then dbms_output.put_line('1');
        when 2 then dbms_output.put_line('2');
        when 3 then dbms_output.put_line('3');
        when 4 then dbms_output.put_line('4');
        else dbms_output.put_line('more');
       end case;
  end;

循环语句：

无限制循环：

  /**
   * loop 循环
   */
  declare
  r_number number :=0;
  begin
    loop
    -- 使用if和exit命令退出
      if r_number > 4 then exit;
      end if;
      dbms_output.put_line('number:'||r_number);
      r_number := r_number+1;
    end loop;
  end;
 
  declare
  r_number number :=0;
  begin
    loop
    -- 使用exit when命令退出
      exit when r_number >4;
      dbms_output.put_line('number:'||r_number);
      r_number := r_number+1;
    end loop;
  end;

While循环：

/*
   * while 循环
   */
  declare
  r_number number :=0;
  begin
    while r_number <5 loop
      dbms_output.put_line(r_number);
      r_number := r_number + 1;
    end loop;
    dbms_output.put_line(r_number);
  end;

for 循环：

  /*
   * for 循环
   */
  declare
  r_number number :=5;
  begin
    for var_index in 1..r_number loop
      dbms_output.put_line(var_index);
    end loop;
  end;
  
  declare
  cursor my_cursor is select * from emp;         
  begin
    for cursor_record in my_cursor loop
      dbms_output.put_line(cursor_record.ename);
    end loop;
  end;

PL/SQL 控制语句