我正在尝试更新Microsoft报告.它的作用是写出从转换过程中排除的客户数量以及原因.目前,程序将所有已删除的客户端写回服务器,然后将其查询回来以填充带有结果的专业表.
这是当前的查询:
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@H_404_5@我想做的是不将DeletedClients写入服务器,因为它已作为DataTable存在于我的程序的内存中,它只会减慢报告速度并使用我们不需要保存的信息填充数据库.
我的主要问题是:要么:
如何查询数据表以创建一个新的内存数据表,其结果与我写出sql服务器并使用上面的查询读回来的结果相同?
要么
如何在Microsoft Reports中为Tablix中的项目执行group by子句= Fields!Reason.Value = Fields!Number.Value = Fields!percentage.Value类似于上面查询的返回结果?
解决方法
您可以使用DataTable.Select查询DataTable.
DataTable table = GetDataTableResults(); DataTable results = table.Select("SomeIntColumn > 0").CopyToDataTable();@H_404_5@或者对于更复杂的查询,您可以使用LINQ查询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 });@H_404_5@