Sql 选择具有优先级值的非重复行
我有一个表,其中包含带有测量值的行。对于同一批id,可以指定多个度量值。我希望在以下条件下获得正确的值:Sql 选择具有优先级值的非重复行,sql,sql-server,select,duplicates,Sql,Sql Server,Select,Duplicates,我有一个表,其中包含带有测量值的行。对于同一批id,可以指定多个度量值。我希望在以下条件下获得正确的值: 如果给定批次只有一行,则度量值有效 如果同一类型有多行,则度量值无效,返回的类型应为“无效”,值为0 如果存在多个不同类型的行(一个“已获取”和一个“已验证”),则返回的行必须是“已验证”的行 样本数据: create table measures ( batch int, type varchar(24), value int ); insert into meas
- 如果给定批次只有一行,则度量值有效
- 如果同一类型有多行,则度量值无效,返回的类型应为“无效”,值为0
- 如果存在多个不同类型的行(一个“已获取”和一个“已验证”),则返回的行必须是“已验证”的行
create table measures (
batch int,
type varchar(24),
value int
);
insert into measures select 01,'Verified',10;
insert into measures select 02,'Acquired',34;
insert into measures select 03,'Verified',22;
insert into measures select 03,'Verified',24;
insert into measures select 04,'Verified',32;
insert into measures select 04,'Acquired',34;
insert into measures select 05,'Acquired',42;
insert into measures select 05,'Acquired',44;
样本输出:
01 Verified 10
02 Acquired 34
03 Invalid 0
04 Verified 32
05 Invalid 0
你的逻辑有点难以理解。通过条件聚合,您可以做您想做的事情。它认为逻辑是:
select batch,
(case when count(*) = 1 then max(type)
when min(type) = max(type) then 'Invalid'
else coalesce(max(case when type = 'Verified' then 'Verified' end), 'Invalid')
end) as type,
(case when count(*) = 1 then max(value)
when min(type) = max(type) then 0
else coalesce(max(case when type = 'Verified' then value end), 0)
end) as value
from measures m
group by batch;
使用windows功能:
;WITH CountTypesPerBatch AS
(
SELECT batch, type, value,
COUNT(CASE WHEN type = 'Verified' THEN 1 END)
OVER (PARTITION BY batch) AS verified,
COUNT(CASE WHEN type = 'Acquired' THEN 1 END)
OVER (PARTITION BY batch) AS acquired,
ROW_NUMBER() OVER (PARTITION BY batch
ORDER BY IIF(type='Verified',1, 2)) seq
FROM measures
)
SELECT DISTINCT batch,
CASE
WHEN verified > 1 OR acquired > 1 THEN 'invalid'
WHEN verified = 1 THEN 'verified'
ELSE 'acquired'
END,
CASE
WHEN verified > 1 OR acquired > 1 THEN 0
ELSE value
END
FROM CountTypesPerBatch
WHERE seq = 1
您的第一个条件似乎收缩了另外两个条件。这是编写INSERT语句的一种非常奇怪的方式。VALUES子句有什么问题?您使用的是哪种产品?“SQL”只是一种查询语言,而不是特定数据库产品的名称。请为您正在使用的数据库产品添加。数据库引擎是SQL SERVER,我添加了标记。