基于列值中的一个条件选择 SQL

Question

有人可以帮助我使用以下数据进行 SQL 查询吗？

每当我看到该类型处于停用状态而与相同 ID 中的其他类型无关时，我只需要获取停用值，其余值应为空。

select     id,     
pid,    
type,    
case when type='deactivate' then null as value1 else value1 end,     
case when type='deactivate' then  null as value2 else value2 end,     
case when type='deactivate' then  null as value3 else value3 end,     
case when type='deactivate' then null as value4 else value4 end,     
case when type='deactivate' then null as value5 else value5 end,     
case when type='deactivate' then value6 end,     
case when type='deactivate' then deactivate_date end,     
case when type='deactivate' then status end     
from typetable  

但每当 pid 发生变化时，我都会得到 value1 到 5 的值。 每当我看到 type='deactivate' 时，我的数据中有什么方法我必须忽略同一 ID 中所有类型的 value1 到 5 的值吗？ 输出应该类似于下面提到的 ID-1 和 3 的空值。

id  pid type    value1  value2  value3  value4  value5  value6  deactive date   Status
0   1   case    99  null    null    null    null    null    null    
0   2   test    null    101 null    null    null    null    null    
0   3   levels  null    null    CAAD    null    null    null    null    
0   4   package null    null    null    null    DSIT    null    null    

1   1   case    null    null    null    null    null    null    null    
1   2   test    null    null    null    null    null    null    null    
1   3   levels  null    null    null    null    null    null    null    
1   4   package null    null    null    null    null    null    null    
1   5   deactivate  null    null    null    null    null    9999999 9/1/2014    Void ID

2   1   case    CLR 6#  null    null    null    null    null    null    
2   2   test    null    6   null    null    null    null    null    
2   3   levels  null    null    MAA null    null    null    null    

3   1   case    null    null    null    null    null    null    null    
3   2   test    null    null    null    null    null    null    null    
3   3   levels  null    null    null    null    null    null    null    
3   4   package null    null    null    null    null    null    null    
3   5   deactivate  null    null    null    null    null    9999999 1/7/2016    Closed

Answer 1

declare @t table (id int, pid int, col1 varchar(10), col2 varchar(10)) 
insert into @t 
       values (1, 1, 'askjdf', 'laskjdf')
            , (1, 2, 'asksfjdf', 'ljdf')
            , (2, 1, 'askjdf', 'laskjdf')
            , (2, 2, 'deact', 'laskjdf');

select t.* 
from @t t 
where not exists (select 1 from @t tm where tm.id = t.id and tm.col1 = 'deact') 
union all 
select t.id, t.pid, t.col1, null  
from @t t 
where     exists (select 1 from @t tm where tm.id = t.id and tm.col1 = 'deact') 
order by id, pid;

Answer 2

这样的事情会起作用：

select
    id, pid,
    case when masked = 0 then value 1 else null end as value1,
    ...
from <table> t cross apply (
    select max(case when t2.type = 'deactivate' then 1 else 0 end)
    from <table> t2
    where t2.id = t.id
) m(masked)

类似，而且可能更好：

with data as (
    select *,
        max(case when type = 'deactivate' then 1 else 0 end)
            over (partition by id) as masked
    from <table>
)
select
    id, pid,
    case when masked = 0 then value 1 else null end as value1,
    ...
from data;

Answer 3

如果您在id AND type='deactivate' 上进行自左连接并检查连接表的类型字段而不是左表的类型字段，则最简洁且最简单：

select t1.id,t1.pid,t1.type,
case when t2.type='deactivate' then null else t1.value1 end AS value1,
case when t2.type='deactivate' then null else t1.value2 end AS value2, 
case when t2.type='deactivate' then null else t1.value3 end AS value3, 
case when t2.type='deactivate' then null else t1.value4 end AS value4, 
case when t2.type='deactivate' then null else t1.value5 end AS value5, 
case when t2.type='deactivate' then t1.value6 end AS value6, 
case when t2.type='deactivate' then t1.deactivate_date end AS deactivate_date, 
case when t2.type='deactivate' then t1.status end from typetable t1 
LEFT JOIN typetable t2 ON t1.id=t2.id AND t2.type='deactivate'