Question

create or replace procedure d_name_legzdins (id in dept.deptno%type) as d_name_legzdins varchar(20);

BEGIN

SELECT dname into d_count_legzdins FROM dept WHERE deptno=id;

if (SELECT count(empno) from emp where deptno=id)=0 THEN

raise_application_error(-20101, 'There are no employees currently working at this department!');

else

DBMS_OUTPUT.PUT_LINE('There are currently '|| (SELECT count(empno) from emp where deptno=id) ||' employees working at '|| d_count_legzdins ||'department');

END IF;

exception

  when no_data_found then

    DBMS_OUTPUT.PUT_LINE('There is no such department!');

end;'

我刚刚在大学开始这个主题，无论我做什么都无法让它发挥作用

供参考

表dept包含deptno，即derpartment的id和dname，即名称

并且emp包含empno，whcih是员工姓名，deptno是同一个dept id并且是connected

Answer 1

Emils，您的代码中有一些严重的语法错误。可以在 Oracle Docs 中查看 PL/SQL 语法和语义的快速参考指南。您的代码可以这样更改：

create or replace procedure d_name_legzdins (id in dept.deptno%type) 
as 
  v_name_legzdins varchar(20);
  v_emp_cnt number;
begin
 select dname 
 into v_name_legzdins 
 from dept 
 where deptno=id;
 
 begin
   select count(empno)
   into v_emp_cnt
   from  emp where 
   deptno=id;
 exception
   when no_data_found then
     raise_application_error(-20101, 'There are no employees currently working at this department!');
 end;
 
 DBMS_OUTPUT.PUT_LINE('There are currently '|| v_emp_cnt ||' employees working at '|| v_name_legzdins ||' department'); 

exception
  when no_data_found then
    DBMS_OUTPUT.PUT_LINE('There is no such department!');
end;

Answer 2

正如所指出的，您有一些严重的语法错误。清洁这些显然是您的首要任务。但是恕我直言，您的程序布局有些不稳定。您的结构为“良好流程，然后是错误流程，然后是良好流程，然后是错误流程”。我发现一个更清晰的过程是“好的过程然后所有的异常处理”（不可否认，有时是不可能的）。在这种情况下，部门中缺少 Dept 和 No Emp 都是例外。所以在 EXCEPTION 部分处理两者。 Oracle 允许嵌套块，并且每个块都可以有一个异常部分：例如（参见 fiddle]1）。

create or replace procedure d_name_legzdins (id in dept.deptno%type) 
as 
  v_name_legzdins varchar(20);
  v_emp_cnt number;
  
begin

   select d.dname, count(*) 
     into v_name_legzdins,v_emp_cnt 
     from dept d 
     join emp  e on (e.deptno = d.deptno)
    where d.deptno = id
    group by d.dname; 
 
   dbms_output.put_line('There are currently '|| v_emp_cnt || 
                        ' employees working at '|| v_name_legzdins ||' department'
                        ); 
                        
exception
  when no_data_found then 
    -- at this point we know that either the parameter for department (id) is invalid 
    -- or that it is valid but has no employees. Now discover which.
       begin 
           select dname
             into v_name_legzdins    
            from dept 
            where deptno =  id
              and rownum <= 1; 
           -- the department exists, so it does not have any employees.
           raise_application_error(-20101, 'There are no employees currently working at this department!');

    exception
      when no_data_found then
           dbms_output.put_line('There is no such department!');
    end ; -- inner exception    
end d_name_legzdins;

我不明白为什么你只想要一条关于缺少仪态的消息，而想要一个用户定义的没有员工的例外，但这种不一致是你的选择。

创建的程序有编译错误，不知道发生了什么

2 个答案: