I'm using the latest subsonic dll and the latest linq templates from github. The db i'm inserting into is MySQL. Id column on table is primary key auto increment.
Versions:
Subsonic.Core.dll - 3.0.0.3 - (November 18, 2009 Merged pulls from Github).
LinqTemplates - July 29, 2009.
MySQL.Data.CF.dll - 6.1.2.0.
The row is inserted but the id is returned as 0.
Example of the insert:
mysqldb db = new mysqldb.mysqldbDB();
int ID = db.Insert.Into<db.myTable>(
r => r.message,
r => r.name,
r => r.status).Values(
message,
name,
status).Execute();
Am I doing something wrong? Shouldn't the new id be returned, not zero?
Found the bug in subsonic core.
It's in Subsonic.Core.Query.Insert.cs
The Execute method does not have a condition for id's returned that are of type long.
I've rewritten the method in my local version to:
public int Execute()
{
int returner = 0;
object result = _provider.ExecuteScalar(GetCommand());
if(result != null)
{
if(result.GetType() == typeof(decimal))
returner = Convert.ToInt32(result);
else if (result.GetType() == typeof(int))
returner = Convert.ToInt32(result);
else if (result.GetType() == typeof(long))
returner = Convert.ToInt32(result);
else
returner = Convert.ToInt32(result);
}
return returner;
}
I've changed the multiple if statements to else if's and added the type comparison of long. Also I've added the final else condition which does a convert to int. Not sure if that's such a good idea but it works for me.
If someone wants to update the source great. If i find time sometime soon i'll update it myself.
Related
I've got a membership table that records whether a user is a member of a list. When an update to a user's membership occurs a new record is written and the previous records are left as is which allows a history of their memberships to be maintained. To get a user's membership status involves selecting their most recent entry.
An example of some user list membership data is below. The aim is to find a LINQ expression that groups by list and user but only returns the row with most recently inserted record.
List Name, Username, Comment, ExpiresOn, Inserted
Test List, joeb, second update, 2012-03-13 16:55:03, 2012-01-31 22:28:40
Test List, joeb, first update, 2012-02-13 16:55:01, 2012-01-31 22:28:39
Test List, joeb, initial, 2012-01-13 16:55:02, 2012-01-31 22:28:38
An SQL query illustrates how the current list membership status can be extracted.
select ulm2.ID, ulm2.ExpiresOn, ulm2.Comment, ulm2.Inserted
from UserListMembership as ulm1
left outer join UserListMembership ulm2 on ulm1.id = ulm2.id
group by ulm1.userlistid, ulm1.userid;
The question is how to write a LINQ expression for the query that doesn't use a nested FirstOrDefault call which causes my MySQL entity framework provider to throw a "System.NotSupportedException: Specified method is not supported." exception?
Update:
Below is my failing LINQ expression, it throws the "Specified method is not supported" once the FirstOrDefault call is added.
var query = from mem in db.UserListMemberships
where
mem.User.UserUsernames.Any(y => y.Username.ToLower() == username.ToLower())
&& mem.UserList.Account.Subscriptions.Any(x => x.ID == subscriptionID)
&& mem.ExpiresOn > utcNow
group mem by new { mem.UserListID, mem.UserID } into g
select new { UserListMembership = (from mem2 in db.UserListMemberships where mem2.UserListID == g.Key.UserListID && mem2.UserID == g.Key.UserID orderby mem2.Inserted descending select mem2).FirstOrDefault() };
return query.Select(a => a.UserListMembership).ToList();
Without posting code it's hard for anyone to see what your issue is.
Are you not able to just order the results by your date field and then select the first record? Something like users.OrderByDescending(u => u.Inserted).FirstOrDefault()?
I have a struts2 app with spring transactions and JPA2 over hibernate. The problem is that I have some rows in the database that are changed by an external source (some mysql triggers) and in my front app I have an ajax script that checks this values every 2 seconds. I always need to get the latest value, and not a cached one, and for this I found 2 solutions :
String sql = "FROM MyEntity WHERE xId=:id AND connect!=0 AND complete=0 AND (error=NULL OR error=0)";
Query q = this.em.createQuery(sql).setHint("org.hibernate.cacheable", false).setParameter("agId", agentId);
rs = q.getResultList();
if(rs.size() == 1){
intermedObj = (Intermed) rs.get(0);
}
and the other:
String sql = "FROM MyEntity WHERE xxId=:id AND connect!=0 AND complete=0 AND (error=NULL OR error=0)";
Query q = this.em.createQuery(sql).setParameter("agId", agentId);
rs = q.getResultList();
if(rs.size() == 1){
intermedObj = (Intermed) rs.get(0);
//get latest object from DB
em.refresh(intermedObj);
}
em is a instance of EntityManager which is managed by spring.
So, the question is: which is the best approach from these 2? Or maybe there is a better one ?
So you are right, I used hql there, I still have to learn a lot about hibernate an jpa, and java in general. So I guess that the correct way to write that cod in JPQL would be:
String sql = "SELECT m FROM MyEntity m WHERE m.xxId=:id AND m.connect!=0 AND m.complete=0 AND (m.error!=1)";
Query q = this.em.createQuery(sql).setParameter("agId", agentId);
rs = q.getResultList();
if(rs.size() == 1){
intermedObj = (Intermed) rs.get(0);
//get latest object from DB
em.refresh(intermedObj);
}
So the question would be, is this the proper way to make sure that I got the latest row from DB and not a cached record?
As regarding leve2 cache question I do not know if this is activated. How do I check that?
I have the following problem: In our database we record helpdesk tickets and we book hours under tickets. Between those is a visit report. So it is: ticket => visitreport => hours.
Hours have a certain 'kind' which is not determined by a type indicator in the hour record, but compiled by checking various properties of an hour. For example, an hour which has a customer but is not a service hour is always an invoice hour.
Last thing I want is that the definitions of those 'kinds' roam everywhere in the code. They must be at one place. Second, I want to be able to calculate totals of hours from various collections of hours. For example, a flattened collection of tickets with a certain date and a certain customer. Or all registrations which are marked as 'solution'.
I have decided to use a 'layered' database access approach. The same functions may provide data for screen representation but also for a report in .pdf . So the first step gathers all relevant data. That can be used for .pdf creation, but also for screen representation. In that case, it must be paged and ordered in a second step. That way I don't need separate queries which basically use the same data.
The amount of data may be large, like the creation of year totals. So the data from the first step should be queryable, not enumerable. To ensure I stay queryable even when I add the summation of hours in the results, I made the following function:
public static decimal TreeHours(this IEnumerable<Uren> h, FactHourType ht)
{
IQueryable<Uren> hours = h.AsQueryable();
ParameterExpression pe = Expression.Parameter(typeof(Uren), "Uren");
Expression left = Expression.Property(pe, typeof(Uren).GetProperty("IsOsab"));
Expression right = Expression.Constant(true, typeof(Boolean));
Expression isOsab = Expression.Equal(Expression.Convert(left, typeof(Boolean)), Expression.Convert(right, typeof(Boolean)));
left = Expression.Property(pe, typeof(Uren).GetProperty("IsKlant"));
right = Expression.Constant(true, typeof(Boolean));
Expression isCustomer = Expression.Equal(Expression.Convert(left, typeof(Boolean)), Expression.Convert(right, typeof(Boolean)));
Expression notOsab;
Expression notCustomer;
Expression final;
switch (ht)
{
case FactHourType.Invoice:
notOsab = Expression.Not(isOsab);
final = Expression.And(notOsab, isCustomer);
break;
case FactHourType.NotInvoice:
notOsab = Expression.Not(isOsab);
notCustomer = Expression.Not(isCustomer);
final = Expression.And(notOsab, notCustomer);
break;
case FactHourType.OSAB:
final = Expression.And(isOsab, isCustomer);
break;
case FactHourType.OsabInvoice:
final = Expression.Equal(isCustomer, Expression.Constant(true, typeof(Boolean)));
break;
case FactHourType.Total:
final = Expression.Constant(true, typeof(Boolean));
break;
default:
throw new Exception("");
}
MethodCallExpression whereCallExpression = Expression.Call(
typeof(Queryable),
"Where",
new Type[] { hours.ElementType },
hours.Expression,
Expression.Lambda<Func<Uren, bool>>(final, new ParameterExpression[] { pe })
);
IQueryable<Uren> result = hours.Provider.CreateQuery<Uren>(whereCallExpression);
return result.Sum(u => u.Uren1);
}
The idea behind this function is that it should remain queryable so that I don't switch a shipload of data to enumerable.
I managed to stay queryable until the end. In step 1 I gather the raw data. In step 2 I order the data and subsequently I page it. In step 3 the data is converted to JSon and sent to the client. It totals hours by ticket.
The problem is: I get one query for the hours for each ticket. That's hundreds of queries! That's too much...
I tried the following approach:
DataLoadOptions options = new DataLoadOptions();
options.LoadWith<Ticket>(t => t.Bezoekrapport);
options.LoadWith<Bezoekrapport>(b => b.Urens);
dc.LoadOptions = options;
Bezoekrapport is simply Dutch for 'visitreport'. When I look at the query which retrieves the tickets, I see it joins the Bezoekrapport/visitreport but not the hours which are attached to it.
A second approach I have used is manually joining the hours in LINQ, but that does not work as well.
I must do something wrong. What is the best approach here?
The following code snippets are how I retrieve the data. Upon calling toList() on strHours in the last step, I get a hailstorm of queries. I've been trying for two days to work around it but it just doesn't work... Something must be wrong in my approach or in the function TreeHours.
Step 1:
IQueryable<RelationHoursTicketItem> HoursByTicket =
from Ticket t in allTickets
let RemarkSolved = t.TicketOpmerkings.SingleOrDefault(tr => tr.IsOplossing)
let hours = t.Bezoekrapport.Urens.
Where(h =>
(dateFrom == null || h.Datum >= dateFrom)
&& (dateTo == null || h.Datum <= dateTo)
&& h.Uren1 > 0)
select new RelationHoursTicketItem
{
Date = t.DatumCreatie,
DateSolved = RemarkSolved == null ? (DateTime?)null : RemarkSolved.Datum,
Ticket = t,
Relatie = t.Relatie,
HoursOsab = hours.TreeHours(FactHourType.OSAB),
HoursInvoice = hours.TreeHours(FactHourType.Invoice),
HoursNonInvoice = hours.TreeHours(FactHourType.NotInvoice),
HoursOsabInvoice = hours.TreeHours(FactHourType.OsabInvoice),
TicketNr = t.Id,
TicketName = t.Titel,
TicketCategorie = t.TicketCategorie,
TicketPriority = t.TicketPrioriteit,
TicketRemark = RemarkSolved
};
Step 2
sort = sort ?? "TicketNr";
IQueryable<RelationHoursTicketItem> hoursByTicket = GetRelationHours(relation, dateFrom, dateTo, withBranches);
IOrderedQueryable<RelationHoursTicketItem> orderedResults;
if (dir == "ASC")
{
orderedResults = hoursByTicket.OrderBy(sort);
}
else
{
orderedResults = hoursByTicket.OrderByDescending(sort);
}
IEnumerable<RelationHoursTicketItem> pagedResults = orderedResults.Skip(start ?? 0).Take(limit ?? 25);
records = hoursByTicket.Count();
return pagedResults;
Step 3:
IEnumerable<RelationHoursTicketItem> hours = _hourReportService.GetRelationReportHours(relation, dateFrom, dateTo, metFilialen, start, limit, dir, sort, out records);
var strHours = hours.Select(h => new
{
h.TicketNr,
h.TicketName,
RelationName = h.Relatie.Naam,
h.Date,
TicketPriority = h.TicketPriority.Naam,
h.DateSolved,
TicketCategorie = h.TicketCategorie == null ? "" : h.TicketCategorie.Naam,
TicketRemark = h.TicketRemark == null ? "" : h.TicketRemark.Opmerking,
h.HoursOsab,
h.HoursInvoice,
h.HoursNonInvoice,
h.HoursOsabInvoice
});
I don't think your TreeHours extension method can be converted to SQL by LINQ in one go. So are evaluated on execution of each constructor of the row, causing a 4 calls to the database in this case per row.
I would simplfy your LINQ query to return you the raw data from SQL, using a simple JOIN to get all tickets and there hours. I would then group and filter the Hours by type in memory. Otherwise, if you really need to perform your operations in SQL then look at the CompiledQuery.Compile method. This should be able to handle not making a query per row. I'm not sure you'd get the switch in there but you may be able to convert it using the ?: operator.
I have an mssql table with money type column.
I'm trying to update that and getting the error "1000000,000 is out of interval".
Here is the code:
TradingResult trading = new TradingResult() { Id = 1 };
trading.Price = 1000000.00M;
context.Trading.Attach(trading);
context.Entry(trading).Property(o => o.Price).IsModified = true;
context.SaveChanges();
Works fine when price has one less zero or try to update via query analyzer.
I think the problem is the precision param, how can i change this ?
Hallo,
I have web service that has multiple methods that can be called. Each time one of these methods is called I am logging the call to a statistics database so we know how many times each method is called each month and the average process time.
Each time I log statistic data I first check the database to see if that method for the current month already exists, if not the row is created and added. If it already exists I update the needed columns to the database.
My problem is that sometimes when I update a row I get the "Row not found or changed" exception and yes I know it is because the row has been modified since I read it.
To solve this I have tried using the following without success:
Use using around my datacontext.
Use using around a TransactionScope.
Use a mutex, this doesn’t work because the web service is (not sure I am calling it the right think) replicated out on different PC for performance but still using the same database.
Resolve concurrency conflict in the exception, this doesn’t work because I need to get the new database value and add a value to it.
Below I have added the code used to log the statistics data. Any help would be appreciated very much.
public class StatisticsGateway : IStatisticsGateway
{
#region member variables
private StatisticsDataContext db;
#endregion
#region Singleton
[ThreadStatic]
private static IStatisticsGateway instance;
[ThreadStatic]
private static DateTime lastEntryTime = DateTime.MinValue;
public static IStatisticsGateway Instance
{
get
{
if (!lastEntryTime.Equals(OperationState.EntryTime) || instance == null)
{
instance = new StatisticsGateway();
lastEntryTime = OperationState.EntryTime;
}
return instance;
}
}
#endregion
#region constructor / initialize
private StatisticsGateway()
{
var configurationAppSettings = new System.Configuration.AppSettingsReader();
var connectionString = ((string)(configurationAppSettings.GetValue("sqlConnection1.ConnectionString", typeof(string))));
db = new StatisticsDataContext(connectionString);
}
#endregion
#region IStatisticsGateway members
public void AddStatisticRecord(StatisticRecord record)
{
using (db)
{
var existing = db.Statistics.SingleOrDefault(p => p.MethodName == record.MethodName &&
p.CountryID == record.CountryID &&
p.TokenType == record.TokenType &&
p.Year == record.Year &&
p.Month == record.Month);
if (existing == null)
{
//Add new row
this.AddNewRecord(record);
return;
}
//Update
existing.Count += record.Count;
existing.TotalTimeValue += record.TotalTimeValue;
db.SubmitChanges();
}
}
I would suggest letting SQL Server deal with the concurrency.
Here's how:
Create a stored procedure that accepts your log values (method name, month/date, and execution statistics) as arguments.
In the stored procedure, before anything else, get an application lock as described here, and here. Now you can be sure only one instance of the stored procedure will be running at once. (Disclaimer! I have not tried sp_getapplock myself. Just saying. But it seems fairly straightforward, given all the examples out there on the interwebs.)
Next, in the stored procedure, query the log table for a current-month's entry for the method to determine whether to insert or update, and then do the insert or update.
As you may know, in VS you can drag stored procedures from the Server Explorer into the DBML designer for easy access with LINQ to SQL.
If you're trying to avoid stored procedures then this solution obviously won't be for you, but it's how I'd solve it easily and quickly. Hope it helps!
If you don't want to use the stored procedure approach, a crude way of dealing with it would simply be retrying on that specific exception. E.g:
int maxRetryCount = 5;
for (int i = 0; i < maxRetryCount; i++)
{
try
{
QueryAndUpdateDB();
break;
}
catch(RowUpdateException ex)
{
if (i == maxRetryCount) throw;
}
}
I have not used the sp_getapplock, instead I have used HOLDLOCK and ROWLOCK as seen below:
CREATE PROCEDURE [dbo].[UpdateStatistics]
#MethodName as varchar(50) = null,
#CountryID as varchar(2) = null,
#TokenType as varchar(5) = null,
#Year as int,
#Month as int,
#Count bigint,
#TotalTimeValue bigint
AS
BEGIN
SET NOCOUNT ON;
BEGIN TRAN
UPDATE dbo.[Statistics]
WITH (HOLDLOCK, ROWLOCK)
SET Count = Count + #Count
WHERE MethodName=#MethodName and CountryID=#CountryID and TokenType=#TokenType and Year=#Year and Month=#Month
IF ##ROWCOUNT=0
INSERT INTO dbo.[Statistics] (MethodName, CountryID, TokenType, TotalTimeValue, Year, Month, Count) values (#MethodName, #CountryID, #TokenType, #TotalTimeValue, #Year, #Month, #Count)
COMMIT TRAN
END
GO
I have tested it by calling my web service methods by multiple threads simultaneous and each call is logged without any problems.