我尝试更新Microsoft报告。它所做的是写出来的有多少客户，其中不包括在转换过程和原因是什么。目前，该方案将所有被删除的客户机到服务器，然后将查询其回补一个专业表的结果。

I am trying to update a Microsoft report. What it does is write out how many clients where excluded from a conversion process and for what reason. Currently the program writes all of the deleted clients back to the server then queries it back to fill a specialty table with the results.

下面是当前查询：

SELECT  DeletedClients.Reason, 
        COUNT(DeletedClients.Reason) AS Number, 
        CAST(CAST(COUNT(DeletedClients.Reason) AS float) 
            / CAST(t.Total AS float) 
            * 100 AS numeric(4, 1)) AS percentage
FROM DeletedClients CROSS JOIN
    (SELECT COUNT(*) AS Total
    FROM DeletedClients AS DeletedClients_1
    WHERE (ClinicID = @ClinicID)) AS t
WHERE (DeletedClients.ClinicID = @ClinicID) 
    AND (DeletedClients.TotalsIdent = @ident)
GROUP BY DeletedClients.Reason, t.Total
ORDER BY Number DESC

我想要做的是不写 DeletedClients 到服务器上，因为它已经存在于记忆在我的计划是一个DataTable，它只是减缓报告填充信息的数据库，我们不需要保存。

What I would like to do is not write DeletedClients to the server as it already exists in memory in my program as a DataTable and it is just slowing down the report and filling the database with information we do not need to save.

我的主要问题是，无论是：

如何查询一个数据表，使具有相同的结果，如果我写出来的SQL服务器内存中的数据表中的一个新的读回与上面的查询？

How do I query a data table to make a new in memory data table that has the same results as if I wrote out the the SQL server and read it back in with the query above?

或

如何在Microsoft报告你做一个group by子句中的Tablix项目以打​​开 =领域！Reason.Value =领域！数量.value的 =领域！percentage.Value 成类似返回的结果的东西从上面的查询？

How in Microsoft Reports do you do a group by clause for items in a Tablix to turn =Fields!Reason.Value =Fields!Number.Value =Fields!percentage.Value into something similar to the returned result from the query above?

推荐答案

您可以使用DataTable.Select来查询数据表。

You can use DataTable.Select to query the DataTable.

DataTable table = GetDataTableResults();
DataTable results = table.Select("SomeIntColumn > 0").CopyToDataTable();

或者更复杂的查询，你可以使用LINQ查询数据表：

Or for more complex queries, you can use LINQ to query the DataTable:

DataTable dt = GetDataTableResults();

var results = from row in dt.AsEnumerable()
              group row by new { SomeIDColumn = row.Field<int>("SomeIDColumn") } into rowgroup
              select new
              {
                  SomeID = rowgroup.Key.SomeIDColumn,
                  SomeTotal = rowgroup.Sum(r => r.Field<decimal>("SomeDecimalColumn"))
              };                    

DataTable queryResults = new DataTable();
foreach (var result in query)
    queryResults.Rows.Add(new object[] { result.SomeID, result.SomeTotal });