如何在Oracle SQL中将用户输入作为NVL（）函数的替代输出？

Question

此查询检查给定经理下的所有员工以及级别，经理ID，经理名称。运行此命令时，level 1的管理员名称列包含null，这基本上意味着它们直接位于输入的manager之下。我如何在级别1的“经理名称”列中获取输入的经理的名称。

我正在使用Oracle 11g。

    select id,(firstname||' '||lastname) as name,managerid, 
    nvl(prior (firstname||' '||lastname),'want user input shown here') as manager_name, level
    from employee
    connect by prior id = managerid
    start with managerid=(select id from employee where firstname = '&firstname' and 
    lastname='&lastname') order by level;

Answer 1

我在示例中使用了stock scott.emp表，您应该能够相应地对其进行修改：

WITH starter AS (
  SELECT b.empno, b.ename 
  FROM scott.emp b
  WHERE b.ename = 'KING'
)
SELECT a.ename, 
       NVL(PRIOR(a.ename), (SELECT s.ename FROM starter s))
FROM scott.emp a
CONNECT BY a.mgr = PRIOR (a.empno)
START WITH a.mgr = (SELECT s.empno FROM starter s);

我承认，这有点麻烦，但是可以完成工作。

Answer 2

用户输入的意思是名字和姓氏，这里是替换变量。

您可以如下所示使用&&。

select id,(firstname||' '||lastname) as name,managerid, 
    nvl(prior (firstname||' '||lastname),'&&firstname &&lastname') as manager_name, level
    from employee
    connect by prior id = managerid
    start with managerid=(select id from employee where firstname = '&&firstname' and 
    lastname='&&lastname') order by level;

干杯！