I would like to update data using C# and Entity Framework Core.
But the result of Swagger is different from the result of executing the API in axios.
The variable "todoList" is stored with data in Swagger and returned null in axios.
Why a value of "todoList" is null?
Please tell me about it.
Thank you!
This is a Code.
public bool updateCompFlg(string operatorId, string id)
{
// Call Update!
// "_repository is an Interface."
if (_repository.Update(operatorId, id))
{
return true;
}
else
{
return false;
}
}
This is the code that actually updates the data.
public bool Update(string operatorId, string id)
{
// ★The results here are different.
var todoList = _context.TODOLIST.Where(u => u.seqNo.Equals(id)).FirstOfDefault();
todoList.operatorId = operatorId;
todoList.resultFlg = "1";
_context.Update(todoList);
try
{
_context.SaveChange();
return true;
}
catch (SystemException ex)
{
throw ex;
}
}
Related
Hi I am tryin to use Transactions in my application which coded in MVC.net
I have my dbcontext in a layer and I reach it from a business layer. When I run the code its not giving me any errors but its also not making the transaction at all.
This is my context
public class DB : IDisposable
{
public DB()
{
}
private RootDYSContext _ctx = null;
public RootDYSContext ctx
{
get
{
if (_ctx == null)
_ctx = new RootDYSContext();
return _ctx;
}
set
{
_ctx = value;
}
}
public bool Commit()
{
try
{
ctx.SaveChanges();
}
catch (Exception exp)
{
Mesaj = exp.Message;
return false;
}
return true;
}
}
And this is how I am tryin to do transaction which based on here "https://learn.microsoft.com/en-us/ef/core/saving/transactions"
public bool CreateKullanici(VMKullanici
KullaniciData,List<VMRol>RolDataList,VMRol AnaRolData)
{
string mesaj = "";
int kullanici_id;
using (RootDBHelper.DB db = new RootDBHelper.DB())
{
using (var ctx = new RootDBLayer.RootDYSContext())
{
using (DbContextTransaction dbContextTransaction =
ctx.Database.BeginTransaction())
{
try
{
kullanici_id = SaveKullanici(KullaniciData, out
mesaj);
foreach(VMRol rol in RolDataList)
{
VMKullaniciRol KullaniciRolInsertData = new
VMKullaniciRol();
KullaniciRolInsertData.kullanici_id =
kullanici_id;
KullaniciRolInsertData.rol_id = rol.rol_id;
if (rol.rol_id == AnaRolData.rol_id)
KullaniciRolInsertData.ana_rol_mu =
(int)RConstants.EvetHayir.Evet;
else
KullaniciRolInsertData.ana_rol_mu =
(int)RConstants.EvetHayir.Hayir;
bKullaniciRol.SaveKullaniciRol(KullaniciRolInsertData, out mesaj);
}
/*Edit:I think this line made confusion I put this to make sure rollback
dbContextTransaction.Rollback(); */
dbContextTransaction.Commit();
return true;
}
catch
{
dbContextTransaction.Rollback();
return false;
}
}
}
}
}
I expect when I run this I shouldnt get any record at all.I seriously stucked because I dont get any error or any hint at all and this method keeps saving data regardless of rollback.
Thank you in advance.
Edit: I do my save changes part on the insert methods
Adding also code examples for the methods
public int SaveKullanici(VMKullanici KullaniciData, out string mesaj)
{
using (RootDBHelper.DB db = new RootDBHelper.DB())
{
mesaj = "";
PKullanici pKullanici = new PKullanici();
if (KullaniciData.kullanici_id == default(int))
pKullanici.InsertKullanici(db.ctx, KullaniciData);
else
pKullanici.UpdateKullanici(db.ctx, KullaniciData);
if (db.Commit())
{
return KullaniciData.kullanici_id;
}
else
{
mesaj = db.Mesaj;
return -1;
}
}
}
public void InsertKullanici(RootDYSContext ctx, VMKullanici KullaniciData)
{
ctx.TKullanici.Add(KullaniciData.TKullanici);
}
I think your problem is that you do commit and then you want to rollback but you should one thing commit or rollback.
In addition I cant see in your code where you actually doing transaction.commit. Your code has commit function but commit != savechanges.
Idea of transactions (there are different type but) is that you save data to database do some validation or operations and then you say well it looks ok commit or there is an error do rollback.
Also note if you are not do not commit or do rollback then your identity field will get incremented no matter what
I am working with Xamarin forms and I have implemented SQLite database using Sqlite-net-pcl nuget package. The problem is that the database is initially saving a row but is unable to update or delete any row. Here is the code in which I save and delete the database row with a Key.
public Task<int> SaveItemAsync(SQLiteRowData item)
{
if (item.ID != 0)
{
return database.UpdateAsync(item);
}
else
{
return database.InsertAsync(item);
}
}
public Task<int> DeleteItemAsync(SQLiteRowData item)
{
return database.DeleteAsync(item);
}
public Task<int> DeleteItemAsyncWithKey(string key)
{
Task<SQLite.SQLiteRowData> lSQLiteRowTaskData =
App.sqliteConnectionPath.GetItemForKeyAsync(key);
SQLite.SQLiteRowData lSQLiteRowData = lSQLiteRowTaskData.Result;
return database.DeleteAsync(lSQLiteRowData);
}
public async Task<bool> DeleteUserPreferencesAsync()
{
Boolean lReturnValue = false;
try
{
Task<SQLiteRowData> lSQLiteRowDataTask = App.sqliteConnectionPath.GetItemForKeyAsync("UserPreferences"); SQLiteRowData lSQLiteRowData = lSQLiteRowDataTask.Result;
if (lSQLiteRowData != null) {
await DeleteItemAsync(lSQLiteRowData);
lReturnValue = true;
}
}
catch (Exception ex)
{
EMAUtilities.printLogs(ex.Message);
}
return lReturnValue;
}
// Used for saving userpreference
SQLiteRowData lSQLiteRowData = new SQLiteRowData("UserPreferences", lValue);
Task<int> x = SaveItemAsync(lSQLiteRowData);
Can anyone point out the mistake I have done in this, Thanks in advance
I have an ASP.NET MVC action method that accepts a single policyId and processes it, returning a JSON result to indicate success.
public ActionResult MovePolicyToFallout(int policyId)
{
try
{
orchestrator.MovePolicyToFallout(policyId);
return Json(new { Success = true });
}
catch (EntityNotFoundException ex)
{
return HttpNotFound(ex.Message);
}
}
What is a good pattern to make this code accept a list of policyId and process each of them?
You can keep the method you have, then add a method that takes a collection of values and loops over them, calling your method for each one:
public List<ActionResult> MovePoliciesToFallout(List<int> policyIds)
{
var l = new List<ActionResult>();
foreach (int policyId in policyIds)
{
var result = MovePolicyToFallout(policyId);
l.Add(result);
}
return l;
}
Note: it will return a list of results, naturally, rather than one.
I would consider changing the flow of control, such that MovePolicyToFallout does not throw an exception if it can't find the policy.
e.g. below, I've assumed that instead of throwing, the called method returns a boolean.
You can then project the entire list of results, keyed by the PolicyIds:
public ActionResult MovePoliciesToFallout(IEnumerable<int> policyIds)
{
return Json(policyIds.Select(
pId => new
{
PolicyId = pId,
Success = orchestrator.MovePolicyToFallout(pId)
}));
}
An update of rory.ap's post, use a List and a foreach loop
public List<ActionResult> MovePoliciesToFallout(List<int> policyIds)
{
try
{
foreach (int policyId in policyIds)
{
MovePolicyToFallout(policyId);
}
}
catch(EntityNotFoundException ex)
{
return HttpNotFound(ex.Message);
}
return Json(new { Success = true }); //or return view, redirecttoaction etc
}
I'm using EF4.0 and I'm trying to delete a record from the database, but my code keeps throwing the following exception:
A first chance exception of type 'System.Data.UpdateException'
occurred in System.Data.Entity.dll
Here's my code:
public bool ApproveUser(string username)
{
using (var context = new UserRegistrationEntities())
{
// The entry object gets populated correctly
var entry = context.PendingApprovals
.Where(e => e.Username.Equals(username))
.FirstOrDefault();
try
{
context.DeleteObject(entry);
// Also tried context.PendingApprovals.DeleteObject(entry)
context.SaveChanges();
return true;
}
catch
{
return false;
}
}
}
I've stepped through the code and the exception is being thrown at context.SaveChanges();
Am I missing anything? Any help would be much appreciated!
Thanks in advance
Have you set the breakpoint and see if entry has value or not? Try this?
public bool ApproveUser(string username)
{
using (var context = new UserRegistrationEntities())
{
// The entry object gets populated correctly
var entry = context.PendingApprovals
.First(e => e.Username.Equals(username))
if (entry != null) {
try
{
context.PendingApprovals.DeleteObject(entry);
context.SaveChanges();
return true;
}
catch
{
return false;
}
}
}
return false;
}
Try removing it first:
public bool ApproveUser(string username)
{
using (var context = new UserRegistrationEntities())
{
// The entry object gets populated correctly
var entry = context.PendingApprovals
.Where(e => e.Username.Equals(username))
.FirstOrDefault();
try
{
context.PendingApprovals.Remove(entry);
context.DeleteObject(entry);
// Also tried context.PendingApprovals.DeleteObject(entry)
context.SaveChanges();
return true;
}
catch
{
return false;
}
}
}
I'm using a SQLite database in a Windows 8 Store Application.
Furthermore I use the SQLite wrapper sqlite-net to do operations on the database.
I will explain this in detail so that you understand my situation.
There are Model classes that contain the business logic, for example the class Location. Then there are DatabaseModels from which the Database Tables are generated, for example LocationDb.
I don't want to implement the basic database methods like Insert(Model model), Update(Model model), Delete(int id), GetAllRecords() and GetRecord(int id) in every Model class. Instead I want to implement these methods in a base class of all models. This base class of all models is called ModelBase; the base class of all database Models is DbModelBase.
There is no problem implementing the Insert method as follows for all models:
public int Insert(ModelBase model)
{
int id;
using (var db = new SQLite.SQLiteConnection(MainApplication.DBPath))
{
db.Insert(model.GetDbModelFromModel());
id = (int)SQLite3.LastInsertRowid(db.Handle);
}
return id;
}
But I don't know how to implement the other ones using sqlite-net.
I need to find a specific data record in a specific table. I have a model object which contains the id. But how to make one method work with all model classes without explicitly calling the specific table?
The following code works for a single specific database table...
using (var db = new SQLite.SQLiteConnection(MainApplication.DBPath))
{
var queryResult = db.Table<LocationDb>().Where(l => l.Id == model.Id);
if (queryResult.Count() == 1)
{
db.Update(new TeacherDb(model));
}
}
... but I can not write
var queryResult = db.Table<typeof(databaseModel)>().Where(t => t.Id == model.Id);
Write a generic function for that.
What about this solution:
public class BaseModel<T> where T : Type
{
protected T Id;
/// <summary>
/// Adds a new record to data base. It doesn't check for record existance.
/// </summary>
/// <returns></returns>
protected BaseModel<T> Add()
{
try
{
var entities = Variable.CurrentEntities;
var dbSet = entities.Set<BaseModel<T>>();
var result = dbSet.Add(this);
entities.SaveChanges();
return result;
}
catch (Exception exception)
{
LogException.HandleException(exception);
return null;
}
}
protected bool Update()
{
try
{
var entities = Variable.CurrentEntities;
var dbSet = entities.Set<BaseModel<T>>();
var original = dbSet.Find(this);
entities.Entry(original).CurrentValues.SetValues(this);
entities.SaveChanges();
return true;
}
catch (Exception exception)
{
LogException.HandleException(exception);
return false;
}
}
protected BaseModel<T> Delete()
{
try
{
var entities = Variable.CurrentEntities;
var dbSet = entities.Set<BaseModel<T>>();
var result = dbSet.Remove(this);
entities.SaveChanges();
return result;
}
catch (Exception exception)
{
LogException.HandleException(exception);
return null;
}
}
protected bool Upsert()
{
try
{
var entities = Variable.CurrentEntities;
var dbSet = entities.Set<BaseModel<T>>();
dbSet.AddOrUpdate(this);
return true;
}
catch (Exception exception)
{
LogException.HandleException(exception);
return false;
}
}
protected BaseModel<T> Save()
{
try
{
var entities = Variable.CurrentEntities;
var dbSet = entities.Set<BaseModel<T>>();
var original = dbSet.Find(Id);
if (original == null)
{
original = dbSet.Add(this);
}
else
{
entities.Entry(original).CurrentValues.SetValues(this);
}
entities.SaveChanges();
return original;
}
catch (Exception exception)
{
LogException.HandleException(exception);
return null;
}
}
}