3

I am using the Microsoft.ACE.OLEDB Driver to query an excel file. The results are then passed to a DataTAble. However, The T-SQL query that I would like to use is not supported by this driver. 

with abc as
(
SELECT Credit, Debit,[Reference 2] As [Job Code]
from xlSheet
WHERE ([Reference 2] LIKE '%JOB%') OR ([Reference 2] LIKE '%CRN%')
union all
SELECT Credit, Debit,[Reference] As [Job Code]
from xlSheet
WHERE ([Reference] LIKE '%JOB%') OR ([Reference] LIKE '%CRN%')
)
SELECT sum(Credit) as  Credit, sum(debit) as Debit,ABS(ROUND(SUM(Debit - Credit),2)) as Total , [Job Code],
            case when ROUND(SUM(Debit - Credit),2) < 0
                then 'JOB'
                else 'JOBR'
            end as 'Trans Code' 
from abc
group by [Job Code]
HAVING ROUND(SUM(debit - credit),2)  <> 0

So, I have broken this into two queries Namely:

SELECT Credit, Debit,[Reference 2] As [Job Code]
    from xlSheet
    WHERE ([Reference 2] LIKE '%JOB%') OR ([Reference 2] LIKE '%CRN%')
    union all
    SELECT Credit, Debit,[Reference] As [Job Code]
    from xlSheet
    WHERE ([Reference] LIKE '%JOB%') OR ([Reference] LIKE '%CRN%')

And a second being :

SELECT sum(Credit) as  Credit, sum(debit) as Debit,ABS(ROUND(SUM(Debit - Credit),2)) as Total , [Job Code], 
            case when ROUND(SUM(Debit - Credit),2) < 0 
                then 'JOB' 
                else 'JOBR' 
            end as 'Trans Code'  
from abc 
group by [Job Code] 
HAVING ROUND(SUM(debit - credit),2)  <> 0

Now I know that one can perform basic select queries on a DataTable, but nothing as complex as this. I have heard about LINQ, and I am sure this could be done via this. But being not familiar with LINQ I need some help in this regard. Failing this, the only other way I see would be to write the results back to a secondary excel file, and re-read the file with the secondary query – but this would be have a huge performance drawback.

4

2 回答 2

1

我们有免费的 LINQ in Action 章节介绍 LINQ 和额外的第 14 章讨论 LINQ to DataSets（您将用于 DataTables），如果您需要一些东西来开始。您可以在http://www.manning.com/marguerie/阅读它们。

于 2012-09-10T18:37:53.360 回答
0

所以我通过使用 Linq to DataTable 解决了我的查询，如下所示：

        var result = from b in dsXLData.Tables[0].AsEnumerable()
                     group b by b.Field<string>("cJobCode")  into grp
                     where grp.Sum(e => Math.Round(e.Field<Double>("debit"),2) - Math.Round(e.Field<Double>("credit"),2)) != 0
                     select new
                     {
                         cJobCode = grp.Key,
                         Credit = Math.Round(grp.Sum(x => x.Field<Double>("credit")), 2),
                         Debit = Math.Round(grp.Sum(x => x.Field<Double>("debit")), 2),
                         Amount_Incl = Math.Round(Math.Abs(grp.Sum(x => x.Field<Double>("debit")) - grp.Sum(x => x.Field<Double>("credit"))), 2),
                         Trans_Code =
                                (
                                    Math.Round(grp.Sum(x => x.Field<Double>("debit")) - grp.Sum(x => x.Field<Double>("credit")), 2) < 0 ? "JOB" : "JOBR"
                                )

                     };
于 2012-09-11T07:37:38.420 回答