Question

我创建了一个查询块，例如：

select employee_number, name,payroll_name,effective_date,action type
from abc papf,
action ppa
where papf.person_id = ppa.person_id

现在，我必须找到具有action_type ='Q'或在表操作中没有任何值的员工。为此，我使用了以下查询：

    select * from 
    (    select employee_number, name,payroll_name,effective_date,action type
        from abc papf,
        action ppa
        where papf.person_id = ppa.person_id
    and action_type = 'Q'
  AND To_char(Nvl(ppa.effective_date, '2019-09-01'), 'YYYY-MM-DD') BETWEEN 
           ('2019-09-01' ) AND ( '2019-12-01' ) 

    UNION
    select employee_number, name,payroll_name,effective_date,action type
        from abc papf,
        action ppa
        where papf.person_id = ppa.person_id
    and action_type IS NULL)

上面的查询给了我输出：

PERSON_NUMBER   NAME     PAYROLL_NAME         EFFECTIVE_DATE          ACTION_TYPE 
101755          AMIH      Bi weekly           2019-10-10                  Q
101755          AMIH      Bi weekly           2019-10-09                  Q
101755          AMIH      Bi weekly           
1010            SAM       Weekly

我想在查询的action_type = NULL部分中添加条件，以便仅返回具有空action_type的雇员，而不返回已处理的雇员，即action_type ='Q' 即员工-应该返回1010而不是没有action_type的第三行101755，因为它已经有2行具有相应的action_type，effective_Date值

Answer 1

您不需要使用UNION，只需一个查询和子查询即可。

select employee_number
       , name
       , payroll_name
       , effective_date
       , action_type
from (
    select employee_number
       , name
       , (select count(name) from abc where name = papf.name) mada
       , payroll_name
       , effective_date
       , action_type
    from abc papf
         , action ppa
    where papf.person_id = ppa.person_id
    and (action_type = 'Q'
    and nvl(ppa.effective_date, to_date('2019-09-01', 'YYYY-MM-DD')) BETWEEN 
        to_date('2019-09-01', 'YYYY-MM-DD') AND to_date('2019-12-01', 'YYYY-MM-DD') or action_type is null)
) where mada = 1 or action_type is not null;

这里是DEMO 希望这会对您有所帮助！

Answer 2

我必须找到具有action_type ='Q'或在表操作中没有任何值的员工。

为此，您先从LEFT JOIN开始，然后进行过滤：

select employee_number, name, payroll_name, effective_date, actiontype
from abc papf left join
     action ppa
     on papf.person_id = ppa.person_id
where ppa.actiontype = 'Q' or ppa.actiontype is null;

以上假设actiontype中的NULL不是ppa。也许更正式的版本是：

select employee_number, name, payroll_name, effective_date, actiontype
from abc papf left join
     action ppa
     on papf.person_id = ppa.person_id
where ppa.actiontype = 'Q' or ppa.person_id is null;

这将检查是否确实没有匹配项。

Answer 3

您可以尝试使用分析功能而不使用并集的以下查询：

Select employee_number, name,payroll_name,effective_date,action type from
(select employee_number, name,payroll_name,effective_date,action type, 
        row_number() over (partition by employee_number order by action_type desc nulls last) as rn
        from abc papf,
        action ppa
        where papf.person_id = ppa.person_id
    and (action_type = 'Q'
  AND To_char(Nvl(ppa.effective_date, '2019-09-01'), 'YYYY-MM-DD') BETWEEN 
           ('2019-09-01' ) AND ( '2019-12-01' ) ) or action_type is null)
Where rn = 1

干杯！

添加条件以仅返回空值

3 个答案: