i have written the following query and it is giving error Unable to cast object of type
System.Data.Objects.ObjectQuery'[ITClassifieds.Models.Viewsearch]' to type 'ITClassifieds.Models.Viewsearch'.
my code is as follows
if (zipcode.Contains(","))//opening of zipcode conatins comma
{
do
{
zipcode = zipcode.Replace(" ", " ");
zipcode = zipcode.Replace(", ", ",");
} while (zipcodecity.Contains(" "));
char[] separator = new char[] { ',' };
string[] temparray = zipcode.Split(separator);
var zipcd = (from u in db.ZipCodes1
where u.CityName == temparray[0] && u.StateAbbr == temparray[1] && u.CityType == "D"
select new Viewsearch
{
Zipcode = u.ZIPCode
}).Distinct();
Viewsearch vs = (Viewsearch)zipcd;
if (zipcd.Count() > 0)
{
zipcode = vs.Zipcode;
locations = "";
}
else
{
tempStr = "";
zipcode = "";
}
}
You need to do
If it will always exist:
Viewsearch vs = zipcd.First()
If not use, and then check for null before using
Viewsearch vs = zipcd.FirstOrDefault()
You could also use Single if there will always be 1 or None.
The Distinct method returns an enumerable collection (in your case, and ObjectQuery<T>, which may contain more than one element. You can't typecast that directly to an item in the collection, you need to use one of the IEnumerable methods to get it:
Viewsearch vs = zipcd.SingleOrDefault();
if ( vs != null )
{
zipcode = vs.Zipcode;
locations = String.Empty;
}
else
{
zipcode = String.Empty;
tempStr = String.Empty;
}
SingleOrDefault will throw an exception if there is more than one item in the collection; if that's a problem, you can also use FirstOrDefault to grab the first item, as one example.
Also, unrelated to your question, but you don't need the temporary array variable for your string separators. The parameter to the Split method is a params array so you can just call it like this:
string[] temparray = zipcode.Split(',');
Replace the zipcd query with:
var cityName = temparray[0];
var stateAbbr = temparray[1];
Viewsearch vs = new Viewsearch {
Zipcode = db.ZipCodes1.Where(u.CityName == cityName && u.StateAbbr == stateAbbr && u.CityType == "D").First().ZIPCode
};
Related
This is my datatables serverside implementation. FilterInput contains 5 variables:
Level <- string
Message <- string
Exception <-string
StartDate <- DateTime
EndDate <- DateTime
For some reason when I run this code as it is, I will always get this error:
{System.NullReferenceException: Object reference not set to an
instance of an object.
This is referring to this line:
data = data.Where(
u => u.Level.ToString().ToLower().Contains(FilterInput.Level.ToLower()) &&
u.Message.ToString().ToLower().Contains(FilterInput.Message.ToLower()) &&
u.Exception.ToString().ToLower().Contains(FilterInput.Exception.ToLower())
).ToList();
However, if I remove the search for FilterInput.Exception, everything runs fine again. I have tested it with input ("abc") or without input ("") and the results are the same. The other FilterInputs don't have the same error.
public JsonResult Search(SearchViewModels Input, EventLogsSearchViewModel FilterInput)
{
JsonResult result = new JsonResult(null);
try
{
var data = dbContext.EventLogs.ToList();
int totalRecords = data.Count;
var modelStructure = new Dictionary<int, string>();
modelStructure.Add(1, "Level");
modelStructure.Add(2, "TimeStamp");
modelStructure.Add(3, "LogEvent");
modelStructure.Add(4, "Message");
modelStructure.Add(5, "MessageTemplate");
modelStructure.Add(6, "Exception");
modelStructure.Add(7, "Properties");
var StartDate = FilterInput.StartDate != default(DateTime);
var EndDate = FilterInput.EndDate != default(DateTime);
if ((!string.IsNullOrEmpty(FilterInput.Level) && !string.IsNullOrWhiteSpace(FilterInput.Level)) ||
(!string.IsNullOrEmpty(FilterInput.Message) && !string.IsNullOrWhiteSpace(FilterInput.Message)) ||
(!string.IsNullOrEmpty(FilterInput.Exception) && !string.IsNullOrWhiteSpace(FilterInput.Exception)) ||
(StartDate && EndDate))
{
data = data.Where(
u => u.Level.ToString().ToLower().Contains(FilterInput.Level.ToLower()) &&
u.Message.ToString().ToLower().Contains(FilterInput.Message.ToLower()) &&
u.Exception.ToString().ToLower().Contains(FilterInput.Exception.ToLower())
).ToList();
data = data.Where(u => u.TimeStamp >= FilterInput.StartDate && u.TimeStamp <= FilterInput.EndDate).ToList();
}
if (!(string.IsNullOrEmpty(Input.Order) && string.IsNullOrEmpty(Input.OrderDir)))
{
var columnName = modelStructure.FirstOrDefault(f => f.Key == Convert.ToInt32(Input.Order));
data = data.AsQueryable().OrderBy(columnName.Value + " " + Input.OrderDir).ToList();
}
int recFilter = data.Count;
data = data.Skip(Input.StartRec).Take(Input.PageSize).ToList();
var modifiedData = data.Select(u => new EventLogsListViewModel
{
Id = u.Id,
Message = u.Message,
MessageTemplate = u.MessageTemplate,
Level = u.Level,
TimeStamp = u.TimeStamp,
Exception = u.Exception,
Properties = u.Properties,
LogEvent = u.LogEvent
});
result = this.Json(new
{
draw = Convert.ToInt32(Input.Draw),
recordsTotal = totalRecords,
recordsFiltered = recFilter,
data = modifiedData,
order = Input.Order,
orderdir = Input.OrderDir
});
}
catch (Exception e)
{
logger.LogError(e, LoggingGlobals.LoadingException);
}
return result;
}
EDIT: The exception still happens even when FilterInput.Exception is not null
I have used linq to store data, below is the code:
var result = (dynamic)null;
var serviceData = (dynamic)null;
var userData = (dynamic)null;
/****Linq 1*****/
serviceData= dtPasscode.AsEnumerable().Select(m => new
{
ACCOUNT_ID = intAccountId,
SUB_ACC_ID = m.Field<string>("ACCOUNT_ID_ALIAS")
});
/**Linq 2**/
userData = DisplyCustomerDetails(Convert.ToInt64(strSubAccountID));
result = serviceData.Concat(userData);
And another linq through function:
/**Function**/
System.Data.EnumerableRowCollection DisplyCustomerDetails(Int64 intAccountId)
{
var result = (dynamic)null;
/** Data Display if no service avaiable **/
IAccount_BL objAccount_BL = new Account_BL();
Customer objCustomer = new Customer();
DataTable dtCustomer = null;
int intErrorCount = 0;
objCustomer.Account_Id = Convert.ToInt64(intAccountId);
dtCustomer = objAccount_BL.GetCustomerDetails(objCustomer, ref intErrorCount);
objAccount_BL = null;
objCustomer = null;
if (intErrorCount == 0)
{
if (dtCustomer != null)
{
if (dtCustomer.Rows.Count > 0)
{
result = dtCustomer.AsEnumerable().Select(m => new
{
ACCOUNT_ID = intAccountId,
SUB_ACC_ID = m.Field<string>("ACCOUNT_ID_ALIAS")
});
}
}
}
return result;
}
I wanted to join both the result of Linq1 & Linq2, I tired Concat & Union, getting below error
'System.Data.EnumerableRowCollection<<>f__AnonymousTypea>' does not contain a definition for 'Concat'
To Concat both enumerables must of the same class; you cannot use anonymous classes. Define a class that has the two fields and change the code to Select them.
Also, don't use ... = (dynamic) null; just assign the variable directly
var serviceData= dtPasscode ...
var userData = DisplyCustomerDetails ...
var result = serviceData.Concat(userData);
I'm simply trying to do this, so later on when I save my values in the database they should be set to null incase the textfield is empty.
int? DeliveryAdrID = null;
int.TryParse(TextBoxDeliveryAdrID.Text, out DeliveryAdrID);
But I'm having an error parsing it along.
The above solution should later on make it possible to save empty textbox values in the database as "NULL" instead of 0.
The whole solution:
int parsedValue;
int? DeliveryAdrID = int.TryParse(TextBoxDeliveryAdrID.Text, out parsedValue) ? parsedValue : (int?)null;
int id = Convert.ToInt32(GridViewData.SelectedValue.ToString());
var data = tf.DBTable.Where(a => a.ID == id).FirstOrDefault();
if (data == null)
{
DBTable mt = new DBTable();
mt.Customer = TextBoxCustomer.Text;
mt.Country = TextBoxCountry.Text;
mt.DeliveryAdrID = parsedValue;
tf.DBTable.AddObject(mt);
tf.SaveChanges();
}
else
{
data.Customer = TextBoxCustomer.Text;
data.Country = TextBoxCountry.Text;
data.DeliveryAdrID = parsedValue;
tf.SaveChanges();
}
}
You cannot give a nullable int to int.TryParse. It must be an int. What you are trying to do can be accomplished like so:
int parsedValue;
int? DeliveryAdrID = int.TryParse(TextBoxDeliveryAdrID.Text, out parsedValue) ? parsedValue : (int?) null;
I'm not sure if this is the right way but I have a web service that returns json. Now I wanted to set a conditional to omit rows returned that have a value of false in cell appearInShowcase. Most of the code is pretty straight forward what it does but the cell that has a true false value is appearInShowcase which is in a table photo. In the ms sql database the appearInShowcase is of type ntext.
public List<wsGalleryPhotos> GetGalleryPhotos(int collectionID)
{
photoDataContext dc = new photoDataContext();
List<wsGalleryPhotos> results = new List<wsGalleryPhotos>();
System.Globalization.CultureInfo ci = System.Globalization.CultureInfo.GetCultureInfo("en-US");
foreach (photo photo in dc.photos.Where(s => s.collectionID == collectionID))
{
if(photo.appearInShowcase == "true")
{
results.Add(new wsGalleryPhotos()
{
photoID = photo.photoID,
collectionID = Convert.ToInt32(photo.collectionID),
name = photo.name,
description = photo.description,
filepath = photo.filepath,
thumbnail = photo.thumbnail
});
}
}
return results;
}
if you want to add a condition, you should do it like this:
public List<wsGalleryPhotos> GetGalleryPhotos(int collectionID)
{
photoDataContext dc = new photoDataContext();
List<wsGalleryPhotos> results = new List<wsGalleryPhotos>();
System.Globalization.CultureInfo ci = System.Globalization.CultureInfo.GetCultureInfo("en-US");
results = dc.photos.Where(s => s.collectionID == collectionID && s.appearInShowcase == "true")
.Select(s => new wsGalleryPhotos
{
photoID = s.photoID,
collectionID = collectionID,
name = s.name,
description = s.description,
filepath = s.filepath,
thumbnail = s.thumbnail
}).ToList();
return results;
}
i have to fetch those records where cityname like'zipcode' where zipcode is variable and apply conditions
var zipcd = (from u in db.ZipCodes1
where u.CityName.Contains(zipcode) && u.CityType == "D"
select u).ToList().Select(u => new Viewsearch
{
Zipcode = u.ZIPCode,
CityName = u.CityName,
stateabbr = u.StateAbbr
}).Distinct();
Viewsearch vs = (Viewsearch)zipcd;
if (zipcd.Count() > 1)
{
locations = "United States;" + vs.stateabbr + ";" + vs.CityName;
}
else if (locations == "")
{
locations = "United States;" + vs.stateabbr + ";" + vs.CityName;
}
else
{
locations = "United States;" + vs.stateabbr + ";" + vs.CityName + "," + locations;
}
if (zipcd.Count() > 3) is greater than 3
{
locations = locations.Replace(locations, "," + "<br>");
}
The problem is that you're casting an iterator to the type of a single element on the line
ViewSearch vs = (ViewSearch)zipcd.
If you want vs to be a single object, you must call First() or FirstOrDefault() on your collection:
ViewSearch vs = zipcd.First(); // Throws if there are no elements
ViewSearch vs = zipcd.FirstOrDefault(); // null if there are no elements
First of all I would suggest that you download and use the lovely LINQPad not only to run your LINQ queries first but also to learn from it (has a lot of samples that you can run right form there, no more config needed)
for your question:
var zipcd = (
from u in db.ZipCodes1
where u.CityName.Contains(zipcode) && u.CityType == "D"
select new Viewsearch
{
Zipcode = u.ZIPCode,
CityName = u.CityName,
stateabbr = u.StateAbbr
}).Distinct().ToList();
As you can see the query works:
Distinct at the end of your query uses IEqualityComparer, and I'm guessing you haven't defined one for Viewsearch. It would look something like this:
public class ViewsearchComparer : IEqualityComparer<Viewsearch>
{
public bool Equals(Viewsearch vs1, Viewsearch vs2)
{
// Implementation
}
public int GetHashCode(Viewsearch vs)
{
// Implementation
}
}
After you have that defined, you pass it into your distinct call:
.Select(u => new Viewsearch
{
Zipcode = u.ZIPCode,
CityName = u.CityName,
Stateabbr = u.StateAbbr
})
.Distinct(new ViewsearchComparer());