如何匹配两个数据表并获取数据 [英] How to match two datatable and fetch the data
问题描述
大家好,有人可以建议我。
我正在winforms创建excel报告如果用户选择jan月,这个报告是月份明智的报告
所有日期将在excel即Jan-1-2013,Jan2..Jan31 ..我做了。我创建了一个函数,我在一个DataTable dt1中调用了该函数,填写了那个日期。
接下来在我的数据库中我有tblCalendar表我有两个feild DoEventDate,事件
tblCalendar
DoEventDate活动
1-jan-13 NewYear
14-jan-13 Sankarthi
excel
ExpectedResult
日期活动备注
1jan 2013 Newyear
2Jan
。
。
.14 Jan 13 Sankarthi
。
。
i fetched(选择DoEventDate,来自tblCalendar的活动)
i保存在datatable dt2 ..
我得到了结果
MYResult
日期活动备注
1jan 2013 Newyear
2Jan Sankaranthi --->这是错误的,应该只在1月14日到来。喜欢上面的预期结果
3
。
。
31
Hi guys anyone can suggest me.
I''m creating excel report in winforms this report is month wise report if user select jan month
all date will in the excel i.e Jan-1-2013,Jan2..Jan31.. That i did. I created one function and i called that function in one DataTable dt1 filled that date.
Next in my database i have tblCalendar table there i have two feild DoEventDate, Events
tblCalendar
DoEventDate Events
1-jan-13 NewYear
14-jan-13 Sankarthi
In excel
ExpectedResult
Date Events Remarks
1jan 2013 Newyear
2Jan
3
.
.
.14 Jan 13 Sankarthi
.
.
31
i fetched (select DoEventDate,Events from tblCalendar)
i kept in datatable dt2..
I got result
MYResult
Date Events Remarks
1jan 2013 Newyear
2Jan Sankaranthi---> This is wrong it should come at Jan14 only. like above expectedResult
3
.
.
31
推荐答案
看起来你可以用LEFT JOIN
来做这个,其中左表有月的所有日期,右表是你的tblCalendar
。
请参阅: SQL连接的可视化表示 [ ^ ]
It looks like you could do this with aLEFT JOIN
where the left table has all of the dates of the month, and the right table is yourtblCalendar
.
See: Visual Representation of SQL Joins[^]
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