I have developed a WCF api which is using nHibernate. I am new to this. I have used session.update to take care of transaction. I have a for loop in which based on select condition I am updating a record ie. If A is present in tabel1 then I am updating the table else inserting a new entry.
I am getting "could not execute query." when trying to execute a select query on a table which was previously being updated by adding a new entry in the table.
What I think is, because I am using session.save(table1) and then trying select entries from that table I am getting an error. Since session.save temporarily locks the table I am not able to execute a select query on that table.
What can be the solution on this?
Update:
This the for loop I am using to check in the database for some field:
using (ITransaction tranx = session.BeginTransaction())
{
savefunction();
tranx.Commit();
}
Save function:
public void savefunction()
{
for (int i = 0; i < dictionary.Count; i++)
{
ICandidateAttachmentManager candidateAttach = new ManagerFactory().GetCandidateAttachmentManager();
CandidateAttachment attach = new CandidateAttachment();
attach = checkCV();
if(attach == null)
{
//insert new entry into table attach
session.save(attach);
}
}
}
checkCV function:
public void checkCV()
{
using (ICandidateAttachmentManager CandidateAttachmentManager = new ManagerFactory().GetCandidateAttachmentManager())
{
IList<CandidateAttachment> lstCandidateAttachment = CandidateAttachmentManager.GetByfkCandidateId(CandidateId);
if (lstCandidateAttachment.Count > 0)
{
CandidateAttachment attach = lstCandidateAttachment.Where(x => x.CandidateAttachementType.Id.Equals(FileType)).FirstOrDefault();
if (attach != null)
{
return null;
}
else
{
return "some string";
}
}
}
}
What happening here is in the for loop if say for i=2 the attach value comes to null that I am entering new entry into attach table. Then for i=3 when it enters checkCV function I get an error at this line:
IList lstCandidateAttachment =
CandidateAttachmentManager.GetByfkCandidateId(CandidateId);
I think it is because since I am using session.save and then trying to read the tabel contents I am unable to execute the query and table is locked till I commit my session. Between the beginTransaction and commit, the table associated with the object is locked. How can I achieve this? Any Ideas?
Update:
I read up on some of the post. It looks like I need to set isolation level for the transaction. But even after adding it doesn't seem to work. Here is how I tried to inplement it:
using (ITransaction tranx = session.BeginTransaction(IsolationLevel.ReadUncommitted))
{
saveDocument();
}
something I don't understand in your code is where you get your nHibernate session.
Indeed you use
new ManagerFactory().GetCandidateAttachmentManager();
and
using (ICandidateAttachmentManager CandidateAttachmentManager = new ManagerFactory().GetCandidateAttachmentManager())
so your ManagerFactory class provides you the ISession ?
then you do:
CandidateAttachment attach = new CandidateAttachment();
attach = checkCV();
but
checkCV() returns either a null or a string ?
Finally you should never do
Save()
but instead
SaveOrUpdate()
Hope that helps you resolving your issue.
Feel free to give more details
Related
I am trying to execute below query
using (var dbcontext = new EVEntities())
{
var data_header = dbcontext.Cl.Where(x => x.PKey ==
header_key).FirstOrDefault();
if (data_header != null)
{
data_header.EstimatedCost = Math.Round(estimated_cost,2);
data_header.ClaimedCost = Math.Round(claimed_cost,2);
dbcontext.Entry<Cl>(data_header).State = System.Data.Entity.EntityState.Modified;
dbcontext.SaveChanges();
Writelog("Updated");
}
}
Here Writelog write in a text file and it is working always. But the field in Cl is not getting updated. In between the data is getting updated also.
Connection String
<connectionStrings><add name="EVEntities" connectionString="metadata=res://*/xxx_Entity_Model.csdl|res://*/xxx_Entity_Model.ssdl|res://*/xxx_Entity_Model.msl; provider=System.Data.SqlClient;provider connection string="data source=xxxxxx;initial catalog=xxxxx;persist security info=True;user id=xx;password=xxxxx;MultipleActiveResultSets=True;App=EntityFramework"" providerName="System.Data.EntityClient"/></connectionStrings>
Edit1
tried raw update also
dbcontext.Database.ExecuteSqlCommand(#"UPDATE dbo.Claims
SET EstimatedCost = #e_cost, ClaimedCost = #c_cost WHERE Pkey =
#p_key",
new SqlParameter("e_cost", Math.Round(estimated_cost, 2)),
new SqlParameter("c_cost", Math.Round(claimed_cost, 2)),
new SqlParameter("p_key", claim_header_key));
same outcome. It get updated in between. No error.
You didn't give us enough information to give you the solution. Therefore I give you a method to debug the problem.
Does the DbContext think that anything must be saved?
What SQL is sent to the database?
When you call SaveChanges, DbContext checks its ChangeTracker to see if anything must be updated. Consider to write some Debug code to detect whether there are changes.
Insert just before SaveChanges:
bool changesDetected = dbContext.ChangeTracker.HasChanges;
It might be that you need to call DetectChanges() first. I'm not sure.
If there are Changes, check if the item that you think that should be updated is changed:
IEnumerable <DbEntityEntry<Cl>> entries = dbContext.ChangeTracker.Entries<Cl>;
// We're expecting exactly one entry:
DbEntityEntry<Cl> myEntry = entries.SingleOrDefault();
Assert(myEntry != null);
If null, try to find out why it is not tracked. Was it tracked after you fetched it, before you changed it? Do you have somewhere tracking switched off? Write some other debug code where you fetch some other data. Is that tracked?
If not null, then apparently your Cl is tracked. It ought to be changed:
Assert(myEntry.State == EntityState.Modified);
If not modified, fetch the original values and the current values:
DbPropertyValues originalValues = myEntry.OriginalValues;
DbPropertyValues currentValues = myEntry.currentValues;
In your debugger, check them, or write some debug code to compare the original value with the current values. Are the changed values correct?
I'm not sure if entity framework will try to update objects that are unmodified and of which the original values are not equal to the current values. We'll find out to see what SQL is created when you do the SaveChanges.
It would be nice if your database can log all communications.
You can also log what entity framework sends to your database. For this, use property DbContext.Database.Log. For example:
dbContext.Database.Log = Console.Write;
dbContext.SaveChanges();
If you can't write to Console, write a method:
private List<string> SqlCommands {get;} = new List<string>();
void LogSqlCommands(string sqlCommand)
{
this.SqlCommands.Add(sqlCommand);
}
And in your method that following debug code:
using (var dbcontext = new EVEntities())
{
this.SqlCommands.Clear();
dbContext.Database.Log = this.LogSqlCommands;
var data_header = ... etc
dbContext.SaveChanges();
}
Put a breakpoint after SaveChanges and check the generated SQL.
Hope these debugging tips help you to find the cause of your problem
I am having difficulties UPDATING the databes via LINQ to SQL, inserting a new record works fine.
The code correctly inserts a new row and adds a primary key, the issue I am having is when I go to update (chnage a value that is already in the database) that same row the database is not updating, it is the else part of the code that does not work correctly. This is strange b/c the DB is properly connected and functioning through the fact that the DataContext inserts a new row with no issues. Checking the database confirms this.
This is the code,
using System;
using System.Collections.Generic;
using System.Linq;
using Cost = Invoices.Tenant_Cost_TBL;
namespace Invoices
{
class CollectionGridEvents
{
static string conn = Settings.Default.Invoice_DbConnectionString;
public static void CostDataGridCellEditing(DataGridRowEditEndingEventArgs e)
{
using (DatabaseDataContext DataContext = new DatabaseDataContext(conn))
{
var sDselectedRow = e.Row.Item as Cost;
if (sDselectedRow == null) return;
if (sDselectedRow.ID == 0)
{
sDselectedRow.ID = DateTime.UtcNow.Ticks;
DataContext.Tenant_Cost_TBLs.InsertOnSubmit(sDselectedRow);
}
else
{
// these two lines are just for debuging
long lineToUpdateID = 636154619329526649; // this is the line to be updated primary key
long id = sDselectedRow.ID; // this is to check the primary key on selected line is same
// these 3 lines are to ensure I am entering actual data into the DB
int? amount = sDselectedRow.Cost_Amount;
string name = sDselectedRow.Cost_Name;
int? quantity = sDselectedRow.Cost_Quantity;
sDselectedRow.Cost_Amount = amount;
sDselectedRow.Cost_Name = name;
sDselectedRow.Cost_Quantity = quantity;
}
try
{
DataContext.SubmitChanges();
}
catch (Exception ex)
{
Alert.Error("Did not save", "Error", ex);
}
}
}
}
}
And I am calling the method from this,
private void CostDataGrid_RowEditEnding(object sender, DataGridRowEditEndingEventArgs e)
{
CollectionGridEvents.CostDataGridCellEditing(e);
}
The lineToUpdateID is copied dirrectly from the database and is just there to check against the currently selected rows primary key is the same, so I know I am trying to update the same row.
I have looked through as many of the same type of issues here on SO , such as this one Linq-to-Sql SubmitChanges not updating fields … why?. But still no closer to finding out what is going wrong.
Any ideas would be much appreciated.
EDIT: Cost is just short hand of this using Cost = Invoices.Tenant_Cost_TBL;
You cannot do that. You need to get the record out of the database and then update that record. Then save it back. Like this:
else
{
// first get it
var query =
from ord in DataContext.Tenant_Cost_TBLs
where ord.lineToUpdateID = 636154619329526649
select ord;
// then update it
// Most likely you will have one record here
foreach (Tenant_Cost_TBLs ord in query)
{
ord.Cost_Amount = sDselectedRow.Cost_Amount;
// ... and the rest
// Insert any additional changes to column values.
}
}
try
{
DataContext.SubmitChanges();
}
catch (Exception ex)
{
Alert.Error("Did not save", "Error", ex);
}
Here is an example you can follow.
Or you can use a direct query if you do not want to select first.
DataContext.ExecuteCommand("update Tenant_Cost_TBLs set Cost_Amount =0 where ...", null);
Your object (Cost) is not attached to DB context. You should attach it then save changes. Check solution here
I am trying to save data to my database. What I want is that when the button is pressed, data is saved to the database permanently. I've done tests where code is saved while the application is running. The saved data is viewable. But when I terminate the application, the data is not present when I view the data for that table in visual studio. I've provided the code that I am using for testing.
private void btn_otrFun_Click(object sender, EventArgs e)
{
tblCheese cheese = new tblCheese();
string cheesename = "TestCheese";
cheese.CheeseName = cheesename;
cheese.CheeseGroup = 1;
cheeseEntity.tblCheese.AddObject(cheese);
cheeseEntity.SaveChanges();
}
Here is where I am getting the context form. It is instantiated at the beginnning of the form.
private CheeseWorld_DatabaseEntities cheeseEntity = new CheeseWorld_DatabaseEntities(); //instanciate new database entities
And further I am using this snippet to retrieve data from the the database to dynamically created buttons.
var cheeselist = cheeseEntity.ExecuteStoreQuery<tblCheese>("Select * FROM tblCheese WHERE cheeseGroup = 1", null).ToList();
Hope these further details help. If more are required, let me know.
You've departed from the normal pattern we usually use for this... maybe try putting it back to something like this... (I don't see where you are getting the context)
using (var context = new cheeseEntity()) {
tblCheese cheese = new tblCheese();
cheese.CheeseName = "TestCheese";
cheese.CheeseGroup = 1;
context.tblCheese.Add(cheese);
context.SaveChanges();
}
This is covered in the documentation: http://msdn.microsoft.com/en-us/data/jj593489
(Pay attention to the bottom where it shows how to trace the generated SQL)
NOTE: I am using Add instead of AddObject.
i'm trying to execute an EF update in the following manner but continue to receive this error:
The EntityKey property can only be set when the current value of the property is null.
using (hydraEntities db = new hydraEntities())
{
YouUser = db.youusers.Include("address").Include("entity").Include("youusercontacts.contact").Include("youuserlogins").Include("youusernotes.note").Include("youusernotes.youuser.entity").Where( yu => yu.YOUUserId.Equals(YOUUserId)).First();
}
YouUser.entity.FirstName = txtFirstName.Text;
YouUser.entity.LastName = txtLastName.Text;
YouUser.address.AddressLine1 = txtAddressLine1.Text;
YouUser.address.AddressLine2 = txtAddressLine2.Text;
YouUser.address.City = txtCity.Text;
YouUser.address.State = ddlState.SelectedValue;
YouUser.address.Zipcode = txtZipcode.Text;
using (hydraEntities db = new hydraEntities())
{
db.youusers.AddObject(YouUser);
db.ObjectStateManager.ChangeObjectState(YouUser, System.Data.EntityState.Modified);
db.SaveChanges();
}
Would greatly appreciate any insight on how I can fix this and execute the statement above.
Don't use AddObject in this scenario. It is for inserting a new entity but you are updating existing one. Use Attach instead:
using (hydraEntities db = new hydraEntities())
{
db.youusers.Attach(YouUser);
db.ObjectStateManager.ChangeObjectState(YouUser, System.Data.EntityState.Modified);
db.SaveChanges();
}
In my scenario I was adding objects several times at once through different threads. I had to lock the Model Container object when doing this, to make sure only one object would be processed at once.
I'm making a rather "simple" piece of software and at the moment I'm working with one table in my database and reading from the database works and now I was trying to implement inserting into the database, which seems to work as long as the program is running, but when I stop the program (stop debugging in VS) and launch it again, the rows don't seem to be in the database (already checked the .mdf database itself for the rows but they can't be found).
This is the piece of code:
public void saveKlant(klant nieuweKlant)
{
KlantGegevens newKlant = new KlantGegevens();
newKlant.klantNaam = nieuweKlant.naam;
newKlant.klantStraat = nieuweKlant.straat;
newKlant.klantPostcode = nieuweKlant.postcode;
newKlant.klantHuisNummer = nieuweKlant.huisnummer;
newKlant.klantGSM = nieuweKlant.gsm;
newKlant.klantTel = nieuweKlant.telnummer;
newKlant.klantGebDatum = nieuweKlant.gebDatum;
newKlant.klantEmail = nieuweKlant.email;
using (kapsalonEntities context = new kapsalonEntities())
{
try
{
context.KlantGegevens.AddObject(newKlant);
int test = context.SaveChanges();
}
catch
{
throw new InvalidOperationException("het object kon niet toegevoegd worden");
}
}
}
"test" equals 1 (so context.SaveCHanges() = 1) when running the program.
what would be the reason for the data to not be added persistently? since I do use a Context.SaveChanges()?
Thanks in advance.
It looks like you didn't check of the property where the database each time copies himself toi the debug directory. That's why you always get your default data again. Set the property to "if newer"