如何在mysql的IN子句中添加额外的值

我有一个In子句，里面有查询。我想在中添加'NULL'。 我怎样才能补充呢

这是我的问题

WHERE `e`.`lead_id` IN (
    select lds.lead_id 
        from mortgage_lead_leads lds 
        where lds.loan_officer_id=60
)

---

它给出了10条记录。我想在In子句中添加另一条记录。有人能帮我吗。

您可以使用带有select null from dual的unio

  WHERE `e`.`lead_id` IN 
  (select lds.lead_id from mortgage_lead_leads lds 
    where lds.loan_officer_id=60 
    union 
   select null from dual )

或一个或子句

   WHERE `e`.`lead_id` IN 
  (select lds.lead_id from mortgage_lead_leads lds 
    where lds.loan_officer_id=60 ) or `e`.`lead_id` is null

---

可以将unio与select null from dual一起使用

  WHERE `e`.`lead_id` IN 
  (select lds.lead_id from mortgage_lead_leads lds 
    where lds.loan_officer_id=60 
    union 
   select null from dual )

或一个或子句

   WHERE `e`.`lead_id` IN 
  (select lds.lead_id from mortgage_lead_leads lds 
    where lds.loan_officer_id=60 ) or `e`.`lead_id` is null

---

您不需要将其添加到IN列表中：

WHERE (`e`.`lead_id` IN (select lds.lead_id from mortgage_lead_leads lds
                         where lds.loan_officer_id=60)
       OR `e`.`lead_id` is null)

---

请注意括号处-如果您要添加其他“和条件”语句，这可能很重要。

您不需要将其添加到IN列表中：

WHERE (`e`.`lead_id` IN (select lds.lead_id from mortgage_lead_leads lds
                         where lds.loan_officer_id=60)
       OR `e`.`lead_id` is null)

---

请注意括号处-如果您要添加另一个“AND condition”语句，这可能很重要。

如果我没有弄错，那么您只需添加

union all

和第二个选择即可获得“额外值”：或者，如果我没有弄错，那么您只需添加

union all

和第二个选择即可获得“额外值”：或者