我有用于生成 Gridview.DataSource=DataTable 的临时查询，并且我正在尝试根据 ID（ActionID）获取不同的（无重复）结果，但重复项仍然存在。在选择中使用 distinct 关键字linq 语句似乎没有效果。（仍在与 linq 苦苦挣扎）。还有另一种方法可以做到这一点吗？
DataTable dtSerachResults = new DataTable();
string qryStr = @"SELECT Distinct [ActionID]
, [Title],convert(varchar(11),[DateRaised],109)as DateRaised
, convert(varchar(11)
,[TargetCompletionDate] ,109) as TargetCompletionDate
,dbo.fn_GetPersonelName(fk_PersonnelID) as Responsible
,dbo.fn_GetStatusNameByID(fk_StatusID) as [Status]
,dbo.fn_GetClientNameByID(fk_CustomerID)as Client
,dbo.fn_GetLocationByLocationID(fk_LocationID) as Location
,dbo.fn_GetClientNameByID(fk_CustomerID) as Client
,dbo.fn_GetSourceNameByID(fk_SourceID)as [Source]
, dbo.fn_GetPersonelName(fk_RaisedBy) as RaisedBy
,dbo.fn_GetPersonelName(dbo.fn_GetActionItemPrimaryResponsibleEmployeeID([ActionID]))as [Primary]
,DATEDIFF(DD,DateRaised,GETDATE()) as Diff
,IsApproved=
case IsApproved
when 1 then 'Approved'
when 0 then 'Rejected'
ELSE 'Waiting'
End
FROM [ActionTrackerTable] att
inner join [dbo].[ActionResponsibilitiesTable] art on art.fk_ActionID=att.[ActionID] ";
//title
if (!string.IsNullOrEmpty(ActionTracker.Title))
{
qryStr += " and Title like '" + ActionTracker.Title + "%'";
}
//dateraised
if (ActionTracker.DateRaised > DateTime.MinValue)
{
qryStr += " and DateRaised >= '" + ActionTracker.DateRaised.ToString() + "'";
}
//targetgedate
if (ActionTracker.TargetCompletionDate > DateTime.MinValue)
{
qryStr += " and TargetCompletionDate>= '" + ActionTracker.TargetCompletionDate.ToString() + "'";
}
//Location
if (ActionTracker.Location != null)
{
qryStr += " and fk_LocationID= " + ActionTracker.Location.LocationID.ToString() + "";
}
//client
if (ActionTracker.Customer != null)
{
qryStr += " and fk_CustomerID= " + ActionTracker.Customer.CustomerID.ToString() + "";
}
//source
if (ActionTracker.Source != null)
{
qryStr += " and fk_SourceID= " + ActionTracker.Source.SourceID.ToString() + "";
}
//approval status
if (ActionTracker.SearchApprovalStr == "Approved")
{
qryStr += " and IsApproved= " + 1.ToString();
}
if (ActionTracker.SearchApprovalStr == "Rejected")
{
qryStr += " and IsApproved= " + 0.ToString();
}
if (ActionTracker.SearchApprovalStr == "Waiting")
{
qryStr += " and IsApproved is null";
}
//status
if (ActionTracker.Status !=null)
{
if (ActionTracker.Status.StatusID>0)
{
qryStr += " and [fk_StatusID]= "+ActionTracker.Status.StatusID.ToString();
}
}
//ref num
if (ActionTracker.ActionTrackerID > 0)
{
qryStr += " and ActionID = " + ActionTracker.ActionTrackerID.ToString();
}
if ( (strSearchTerm)=="All" ||(strSearchTerm)=="Select Employee" )
{ )";
//rrun qry
//add the order str
qryStr += " order by ActionID desc ";
System.Data.SqlClient.SqlConnection sqlConn = new System.Data.SqlClient.SqlConnection();
using (sqlConn = ConnectionClass.CreateConnection.publicGetConn())
{
sqlConn.ConnectionString = ConnectionClass.CreateConnection.getConnectionString();
sqlConn.Open();
if (sqlConn.State == System.Data.ConnectionState.Open)
{
using (System.Data.SqlClient.SqlCommand sqlCMD = new System.Data.SqlClient.SqlCommand())
{
sqlCMD.CommandText = qryStr;
sqlCMD.CommandType = System.Data.CommandType.Text;
sqlCMD.Connection = sqlConn;
//parameters
//no 1 is reponsbile
//sqlCMD.Parameters.AddWithValue("@responsibleEmployeeID", responsibleEmployeeID);
//return value
System.Data.SqlClient.SqlDataReader rdr = sqlCMD.ExecuteReader();
//get dataset
DataSet DS = new DataSet();
//load dataset in table
DataTable dt = new DataTable();
dt.Load(rdr);
DS.Tables.Add(dt);
//get Distinct rows based on the Thier rows
var q2 = (from dr in dt.AsEnumerable() select dr).Distinct().CopyToDataTable();
dtSerachResults = (from dr in dt.AsEnumerable() select dr).Distinct().CopyToDataTable();
}
}