An error occurs when I call the function shown below:
Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries."
Function:
[HttpPost]
public ActionResult Index(InsertPo model)
{
var context = new UsersContext();
var po = new Po();
var user = new User();
po.PoId = 12;
po.PoNumber = model.Po.PoNumber;
po.Style = model.Po.Style;
po.Quantity = model.Po.Quantity;
po.Status = "hhh";
po.OrderDate = Convert.ToDateTime("30-12-2011");
po.ShipmentDate = Convert.ToDateTime("2-12-2011");
po.ProductionRate = 10;
po.UserId = 2;
/*buyer.BuyerName = model.Buyer.BuyerName;*/
/* buyer.BuyerId = 1;
buyer.PoId = 10;*/
context.Pos.Add(po);
context.SaveChanges();
return RedirectToAction("Index");
}
Try putting this line outside of your Action method.
var context = new UsersContext();
Related
how I can update a single value for an already existing row in the db by only having a parameters that I want to add it to this attribute
here is my code for a trivial way but didnt work
public bool BuyBook(int BookId, int UserId, int BookPrice){
using (var ctx = new OnlineBooksEntities())
{
User updatedCustomer = (from c in ctx.Users
where c.UserId == UserId
select c).FirstOrDefault();
updatedCustomer.Balance = BookPrice;
ctx.SaveChanges();
}
this.DeleteBook(BookId);
return true;
}
Add an sql query to the method solves the update aim
public bool BuyBook(int BookId, int UserId, int BookPrice)
{
try
{
using (var ctx = new OnlineBooksEntities())
{
User user = ctx.Users.Where(x => x.UserId == UserId).FirstOrDefault();
BookPrice = (int)user.Balance + BookPrice;
int noOfRowUpdated =
ctx.Database.ExecuteSqlCommand("Update Users set Balance = "+BookPrice+ " where UserId ="+UserId);
}
Updating basically means changing an existing row's value. Since you mentioned EF, you can do this by retrieving the object, changing its value, and saving it back. Thus you can do something like this:
using (var db = new MyContextDB())
{
var result = db.Books.SingleOrDefault(b => b.BookPrice == bookPrice);
if (result != null)
{
result.SomeValue = "Your new value here";
db.SaveChanges();
}
}
I'm using a stored procedure to update a table when the user clicks approve however I get message that it was approved successfully but the table wasn't updated.
Update
I'm now only able to update one item; even I select more than one item it is only updating one.
Stored Procedure
Update RequisitionItem
set [status] = 0,
[approve_date] = #approve_date
--[ApprovedBy]=#ApprovedBy
where [status]=-1 and Req_No=#reqNumber and item_no=#item_no
Method
public void SetRequisitionStatus0(List <string> reqNumber,List <string> item_no)
{
SqlConnection connection = new SqlConnection(connectionString);
SqlCommand command = new SqlCommand();
command.CommandText = "requisition_sp_setstatus0";
command.CommandType = CommandType.StoredProcedure;
command.Parameters.Add("#reqNumber", SqlDbType.VarChar);
command.Parameters.Add("#item_no", SqlDbType.VarChar);
//command.Parameters.Add("#ApprovedBy", SqlDbType.VarChar);
command.Parameters.Add("#approve_date", SqlDbType.DateTime).Value = DateTime.Now;
using (command.Connection = connection)
{
try
{
connection.Open();
foreach (var item in reqNumbers)
{
command.Parameters["#reqNumber"].Value = item;
foreach (var item1 in item_no)
{
command.Parameters["#item_no"].Value = item1;
}
command.ExecuteNonQuery();
}
}
finally
{
connection.Close();
}
}
return;
}
I think the foreach loops are messing you up. The inner loop will loop the entire list (item_no) then go back to the outer loop, then the inner loop will go through the entire list again, always giving you the last item. You need a for loop, something like
for(int i = 0; i < reqNumbers.count; i++)
{
command.Parameters["#reqNumber"].Value = reqNumbers[i];
command.Parameters["#item_no"].Value = item_no[i];
command.ExecuteNonQuery();
}
you don't need to close the connection either - the using statement will close it automatically. and you don't need the final return.
How to save mixed data in multiple tables if is checked checkbox:
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create([Bind(Include = "rID,AgentID,karta_br,Datum,patnikID,stanicaOD,stanicaDO,cena,povratna")] tbl_rezervacii tbl_rezervacii)
{
if (ModelState.IsValid)
{
if (tbl_rezervacii.povratna != true)
{
db.tbl_rezervacii.Add(tbl_rezervacii);
db.SaveChanges();
}
else
{
tbl_rezervacii rezervacii = new tbl_rezervacii()
{
???????????????????????
};
db.tbl_rezervacii.Add(rezervacii);
db.SaveChanges();
tbl_povratni povratni = new tbl_povratni()
{
???????????????????????
};
db.tbl_povratni.Add(povratni);
db.SaveChanges();
}
This is code in the controller, and I need to mix data from two forms, and save to two tables, I need something like this, and now my problem is just in else section of implementation.
I make application for Bus Ticket system, and i need this if is checked return way checkbox to add: rID (related with first table tbl_rezervacii), date of returning and relation of returning, include same agent id, price, etc. data which is saved in first tbl_rezervacii table.
MODIFIED CONTROLLER CODE:
public ActionResult Create([Bind(Include = "rID,AgentID,karta_br,Datum,patnikID,stanicaOD,stanicaDO,cena,povratna")] tbl_rezervacii tbl_rezervacii )
{
if (ModelState.IsValid)
{
if (tbl_rezervacii.povratna != true)
{
db.tbl_rezervacii.Add(tbl_rezervacii);
db.SaveChanges();
}
else
{
tbl_rezervacii rezervacii = new tbl_rezervacii()
{
AgentID = tbl_rezervacii.AgentID,
karta_br = tbl_rezervacii.karta_br,
Datum = tbl_rezervacii.Datum,
patnikID = tbl_rezervacii.patnikID,
stanicaOD = tbl_rezervacii.stanicaOD,
stanicaDO = tbl_rezervacii.stanicaDO,
cena = tbl_rezervacii.cena,
povratna = tbl_rezervacii.povratna
};
db.tbl_rezervacii.Add(rezervacii);
//db.SaveChanges();
var rows = db.SaveChanges();
tbl_povratni povratna = new tbl_povratni()
{
rezID = rezervacii.rID,
AgentID = rezervacii.AgentID,
karta_br = rezervacii.karta_br,
DatumP = **tbl_povratni.DatumP**,
patnikID = rezervacii.patnikID,
stanicaPOD = **tbl_povratni.stanicaPOD**,
stanicaPDO = **tbl_povratni.stanicaPDO**,
};
db.tbl_povratni.Add(povratna);
db.SaveChanges();
}
ViewBag.AgentID = new SelectList(db.tbl_agenti, "aID", "agent_ime", tbl_rezervacii.AgentID);
ViewBag.patnikID = new SelectList(db.tbl_patnici, "pID", "ime", tbl_rezervacii.patnikID);
ViewBag.stanicaOD = new SelectList(db.tbl_stanici, "sID", "stanica", tbl_rezervacii.stanicaOD);
ViewBag.stanicaDO = new SelectList(db.tbl_stanici, "sID", "stanica", tbl_rezervacii.stanicaDO);
ViewBag.stanicaPOD = new SelectList(db.tbl_stanici, "sID", "stanica", tbl_rezervacii.tbl_povratni.stanicaPOD);
ViewBag.stanicaPDO = new SelectList(db.tbl_stanici, "sID", "stanica", tbl_rezervacii.tbl_povratni.stanicaPDO);
return View(tbl_rezervacii);
}
return RedirectToAction("Index");
}
How to take data from secondary form and save together in second table?
So, if checkbox is checked, you want to save data into two tables and use primary key of first table (rID) in second table? If rID is auto increment, It will be updated by EF with the value assigned by the database.
tbl_rezervacii rezervacii = new tbl_rezervacii()
{
AgentID = tbl_rezervacii.AgendID,
karta_br = tbl_rezervacii.karta_br
// and so on...
};
db.tbl_rezervacii.Add(rezervacii);
var rows = db.SaveChanges(); // optional, rows will be > 0 if saved successfully.
tbl_povratni povratni = new tbl_povratni()
{
// if rID is auto increment
rID = rezervacii.rID,
// and so on...
};
db.tbl_povratni.Add(povratni);
db.SaveChanges();
I'm refactoring some previously written MVC and Entity Framework code. The way the initial code was written they called a DAL.GetGroupDetail(int groupId) method. In that method it created a ViewModel and populated several properties. Some of those properties are Lists for things like CostCenters, Cities, Groups. I want to break those calls out into their own methods so that they can be re-used in other controllers.
My question is that doing that I'm creating new Contexts using the Using statement. My understanding is that would create multiple connections to the database and thus would slow down the site if multiple users were using it at the same time?
Example, currently this is the basic code:
public ClockGroupViewModel GetClockGroupDetail(int groupId)
{
GroupViewModel cgdv = new GroupViewModel();
using (var ctx = new VTContext())
{
bio_group group = ctx.bio_group.Where(x => x.group_id == groupId).FirstOrDefault();
cgdv.GroupId = group.group_id;
cgdv.GroupName = group.group_name;
cgdv.Cities = ctx.bio_city.ToList();
var clocks = from c in ctx.bio_clock.Where(x => x.group_id == groupId)
select new ClockViewModel
{
ClockID = c.rdr_id.ToString(),
ClockDescription = c.clock_desc,
};
cgdv.ClockList = clocks.ToList();
cgdv.CostCtrList = (from g in ctx.bio_clock_group
from cgc in ctx.bio_clock_group_costctr
where cgc.group_id == g.group_id && g.group_id == groupId
select cgc.cost_ctr).ToList();
}
This how I'm thinking of changing it:
public ClockGroupViewModel GetClockGroupDetail(int groupId)
{
GroupViewModel cgdv = new GroupViewModel();
using (var ctx = new VTContext())
{
bio_group group = ctx.bio_group.Where(x => x.group_id == groupId).FirstOrDefault();
cgdv.GroupId = group.group_id;
cgdv.GroupName = group.group_name;
cgdv.Cities = GetCityList();
cgdv.ClockList = GetClockGroupClockList(group.group_id);
cgdv.CostCtrList = GetGroupCostCenter(group.group_id);
}
}
public List<bio_clock_city> GetCityList()
{
using (var ctx = new VTContext())
{
return ctx.bio_city.ToList();
}
}
public List<ClockViewModel> GetClockGroupClockList(int groupId)
{
using (var ctx = new VTContext())
{
var data = (from c in ctx.bio_clock.Where(x => x.group_id == groupId)
select new ClockViewModel
{
ClockID = c.rdr_id.ToString(),
ClockDescription = c.clock_desc,
}).ToList();
return data;
}
}
public List<string> GetGroupCostCenter(int groupId)
{
using (var ctx = new VTContext())
{
var data = (from g in ctx.bio_clock_group
from cgc in ctx.bio_clock_group_costctr
where cgc.group_id == g.group_id && g.group_id == groupId
select cgc.cost_ctr).ToList();
return data;
}
}
ISSUE:
I have an asp.net mvc 3 app. I'm using EF 4.1 and trying out jqGrid. I'm trying to get data for my jqGrid using the GridData method below. I get the following error on the group of data starting at 'var jsonData = new...'. Any ideas?
ERROR:
{"The array type 'System.String[]' cannot be initialized in a query result.
Consider using 'System.Collections.Generic.List`1[System.String]' instead."}
GridData Method:
public JsonResult GridData(string sidx, string sord, int page, int rows)
{
var result = from a in db.t_harvest_statistics_elk
where a.year == "2008" && a.unit_number == 1
orderby a.id
select a;
int pageIndex = Convert.ToInt32(page) - 1;
int pageSize = rows;
int totalRecords = result.Count(); // context.Questions.Count();
int totalPages = (int)Math.Ceiling((float)totalRecords / (float)pageSize);
var questions = result.Skip(pageIndex * pageSize).Take(pageSize);
var jsonData = new
{
total = totalPages,
page,
records = totalRecords,
rows = (
from question in questions
select new
{
i = question.id,
cell = new string[] { SqlFunctions.StringConvert((double)question.id), SqlFunctions.StringConvert((double)question.total_rec_days), question.year }
}).ToArray()
};
return Json(jsonData);
}
HERE IS AN EXAMPLE THAT DOES WORK
public JsonResult DynamicGridData(string sidx, string sord, int page, int rows)
{
var context = new HaackOverflowDataContext();
int pageIndex = Convert.ToInt32(page) - 1;
int pageSize = rows;
int totalRecords = context.Questions.Count();
int totalPages = (int)Math.Ceiling((float)totalRecords / (float)pageSize);
var questions = context.Questions.OrderBy(sidx + " " + sord).Skip(pageIndex * pageSize).Take(pageSize);
var jsonData = new
{
total = totalPages,
page,
records = totalRecords,
rows = (
from question in questions
select new
{
i = question.Id,
cell = new string[] { question.Id.ToString(), question.Votes.ToString(), question.Title }
}).ToArray()
};
return Json(jsonData);
}
The easiest way to fix the code will be to use something like the following
// to be able to use ToString() below which is NOT exist in the LINQ to Entity
// so we should get the data from the database and save the result locally before
// the next step. One can use .ToList() or to .AsEnumerable(), but one should
// choose only the fields of questions which we will need later
var queryDetails = (from item in questions
select new { item.id, item.total_rec_days, item.year }).ToList();
var jsonData = new {
total = totalPages,
page,
records = totalRecords,
rows = (
from question in queryDetails
select new
{
id = question.Id,
cell = new [] {
question.Id.ToString(),
question.total_rec_days.ToString(),
question.year.ToString()
}
}).ToArray()
};
return Json(jsonData, JsonRequestBehavior.AllowGet);
Your current code contain some small problems like the usage of i = question.id instead of id = question.id.
I would recommend you to read the answer and download the demo from the answer which contains more recent and extended code.
var jsonData = new {
total = totalPages,
page,
records = totalRecords,
rows = (
from question in queryDetails
select new
{
id = question.Id,
cell = new IComparable[]{
question.Id.ToString(),
question.total_rec_days.ToString(),
question.year.ToString()
}
}).ToArray()
};
return Json(jsonData, JsonRequestBehavior.AllowGet);
Can you try modifying your code like :
rows = (
from question in questions.AsEnumerable() //AsEnumerable() is added to switch to LINQ to Entites to eager load the data.
select new
{
i = question.id,
cell = new string[] { SqlFunctions.StringConvert((double)question.id), SqlFunctions.StringConvert((double)question.total_rec_days), question.year }
}).ToArray()
Because the MSDN says that : "You cannot call this function directly. This function can only appear within a LINQ to Entities query." (Though the next line is little confusing in documentation)
You can't use custom functions inside direct queries to you database. Instead you can do something like this:
rows = questions.AsEnumerable()
//or select just that you want questions.Select(q=> new {g.Id, q.Votes,q.Title})
.Select(p=> new {
id = p.Id,
cell = new string[] { SqlFunctions.StringConvert((double)p.id), SqlFunctions.StringConvert((double)p.total_rec_days), p.year }
}).ToArray()
That should work.