I am making a wpf C# app following MVVM. It processes data from accdb (with several connected tables) using DataSet via ServerExplorer. I am trying to make a filtered search right now.
SELECT IDBug, [Date], ReportedBy, Replicated, ReproducableSteps, AppArea, Status, FixedVer, FixedBy, Notes, Title
FROM Bugs
WHERE ([Date] >= ?)
AND ([Date] <= ?)
AND (Status = ?)
AND (AppArea = ?)
AND (Replicated = ?)
AND (ReportedBy = ?)
This was working, but only if use all the filter settings.
int idAr = (from DataRow dr in ars.GetData().Rows
where (string)dr["Area"] == AreaSe.ToString()
select (int)dr["IDArea"]).FirstOrDefault();
int idCust = (from DataRow dr in custs.GetData().Rows
where (string)dr["CustomerName"] == CustomS.ToString()
select (int)dr["IDCustomer"]).FirstOrDefault();
BugTable = bugs.GetT(StartDate, StopDate, State, idAr, replicationS, idCust);
I do have some null values in my data, that is why I tried to do smth similar to
WHERE Title = ? OR (? IS NULL))
instead of
WHERE Title = ?
for each of the parameters. But it messes up the data types...
I don`t think that is smart to write a different sql query for each case, so I need to know how cann I pass "SELECT ALL" to a ? parameter.
CodePudding user response:
You can do use case
in where
clause like this. You can pass null
as default value for the parameter.
So it will return the records for @param
if it is not passed else it will return all records.
SELECT Col1, Col2….
FROM TableName
WHERE ColName = CASE WHEN @param IS NULL THEN ColName ELSE @param END