我正在尝试从其中1个记录符合条件的数据集中选择所有记录。我有一张数据表,其中包含一个人每天的工作时间。如果该周内的某条记录的“已记录”标志设置为“ N”,则我需要选择该人该周的所有记录。这是一个数据示例:
t_hours:
Name Week Weekday Hours Logged
===============================
Jim 1 Mon 8 Y
Jim 1 Wed 8 Y
Jim 1 Fri 8 Y
Jim 2 Mon 8 Y
Jim 2 Wed 8 Y
Bill 1 Mon 8 N
Bill 1 Tue 8 Y
Bill 1 Wed 8 Y
Bill 1 Thu 8 Y
Bill 2 Mon 8 Y
Bill 2 Tue 8 Y
我想编写一个查询,将某人工作周的所有记录更新为Logged ='N',如果他们有一天的Logged ='N'。但是我不知道该如何选择记录。这是我要更新的记录:
Name Week Weekday Hours Logged
===============================
Bill 1 Mon 8 N
Bill 1 Tue 8 Y
Bill 1 Wed 8 Y
Bill 1 Thu 8 Y
我尝试了普通选择,但无法弄清楚在where子句中如何具有两个相关的子查询:
SELECT * FROM t_hours
WHERE (Name = (SELECT t1.Name FROM t_hours t1
where t1.Name = t2.Name and t1.Week = t2.Week and
t1.Logged = 'N') and
Week = (SELECT t2.Week FROM t_hours t2
where t1.Name = t2.Name and t1.Week = t2.Week and
t2.Logged = 'N')
但是这不起作用,非常感谢您的帮助。
返回数据:
SELECT *
FROM t_hours t1
WHERE EXISTS (SELECT 1
FROM t_hours t2
WHERE t1.NAME = t2.NAME
AND t1.week = t2.week
AND t2.logged = 'N');
更新数据:
UPDATE t_hours
SET logged = 'N'
WHERE EXISTS (SELECT 1
FROM t_hours t2
WHERE t1.NAME = t2.NAME
AND t1.week = t2.week
AND t2.logged = 'N');
如果数据集足够大,则可以按名称,星期和记录的类型进行分组。
尝试以下使用存在
select t1.* from table_name t1
where exists( select 1 from table_name t2 where t1.week=t2.week
and t2.logged='N' and t1.name=t2.name
)
您可以使用可更新的CTE:
with toupdate as (
select t.*,
min(logged) over (partition by name, week) as min_logged
from t
)
update toupdate
set logged = min_logged
where min_logged = 'N' and min_logged <> logged;
min(logged)
表达式将返回人/周的任何'N'
值是logged
(其余则是'N'
)。
这是您想要的吗?
'Y'