使用光标显示部门名称.创建一个 PL/SQL 块以使用光标显示部门表中的所有部门名称 [英] Display department names using Cursors.Create a PL/SQL block to display all the department names from the Department table using cursors

问题描述

表格:

Column name Data type Constraints

DEPARTMENT_ID NUMBER(5) PK
DEPARTMENT_NAME VARCHAR2(25) NOT NULL
LOCATION_ID VARCHAR2(15)

这个我试过了.但我仍然没有得到我的输出.有人能帮我得到输出吗.

I have tried this. But still i didn’t get my output. Can somebody help me to get the output.

set serveroutput on;
DECLARE
DEPARTMENT_NAME VARCHAR2(25);
CURSOR dep_cursor IS
SELECT
DEPARTMENT_NAME
FROM
department;
BEGIN
OPEN dep_cursor;
FETCH dep_cursor INTO DEPARTMENT_NAME;
DBMS_OUTPUT.PUT_LINE(‘Department Names are :’ || DEPARTMENT_NAME);
CLOSE dep_cursor;
END;
/

错误信息:未声明绑定变量~".

Error message: Bind variable "~" not declared.

示例输出:

Department Names are :
ADMIN
DEVELOPMENT
TESTING

推荐答案

是关于那些花哨"的您在此处使用的单引号:

It is about those "fancy" single quotes you used here:

DBMS_OUTPUT.PUT_LINE(‘Department Names are :’ || DEPARTMENT_NAME);

应该

DBMS_OUTPUT.PUT_LINE('Department Names are :' || DEPARTMENT_NAME);

---

截至其他错误"你已经做了:没有循环，光标只返回一行，然后显示它.我建议您切换到游标 for 循环，因为它更易于维护:

---

As of other "errors" you've made: without a loop, cursor returns only one row and you then display it. I'd suggest you to switch to a cursor for loop as it is simpler to maintain:

begin
  for cur_r in (select department_name from department) loop
    dbms_output.put_line(cur_r.department_name);
  end loop;
end;
/

这就是你需要的一切；没有声明部分，没有打开或关闭游标，不用担心退出循环...... Oracle 为你做.

This is everything you need; no declaration section, no opening nor closing a cursor, no worrying about exiting the loop ... Oracle does it for you.

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