I have an issue with R2DBC rowsUpdated(). I'm trying to update just one row in the database and get expect it to return 1 count to me for updated rows. But rowsUpdated() return 4 even if one row is updated. The code sample is as follows;
May I ask you to help me?
Thanks in advance...
public class RunQueryRepository implements RunQueryApiRepository {
private final R2dbcEntityTemplate r2dbcEntityTemplate;
public Mono<Integer> runCustomSqlQuery(String sqlQuery) {
Mono<Integer> result = r2dbcEntityTemplate.getDatabaseClient().sql(sqlQuery)
.fetch()
.rowsUpdated();
system.out.println(result.toFuture().get()); // prints 4
return result;
}
}
Related
I am having trouble with en EF method returning duplicate rows of data. When I am running this, in my example, it returns four rows from a database view. The fourth row includes details from the third row.
The same query in SSMS returns four individual rows with the correct details. I have read somewhere about EK and problems with optimization when there are no identity column. But - is there anyway to alter the below code to force EK to read all records with all details?
public List<vs_transactions> GetTransactionList(int cID)
{
using (StagingDataEntities db = new StagingDataEntities())
{
var res = from trans in db.vs_transactions
where trans.CreditID == cID
orderby trans.ActionDate descending
select trans;
return res.ToList();
}
}
Found the solution :) MergeOption.NoTracking
public List<vs_transactions> GetTransactionList(int cID)
{
db.vs_transactions.MergeOption = MergeOption.NoTracking;
using (StagingDataEntities db = new StagingDataEntities())
{
var res = from trans in db.vs_transactions
where trans.CreditID == cID
orderby trans.ActionDate descending
select trans;
return res.ToList();
}
}
I am trying to query records from the DB using Entity Framework. I need to get the total count of records as well as the actual records. What is the best approach to do this
public IEnumerable<mFeedback> RetrieveAll(QueryOptions qOptions)
{
if (qOptions == null)
throw new ArgumentNullException(nameof(qOptions));
using (_db)
{
var feedback = _db.Feedbacks
.Where(f => f.isDeleted == false);
if (qOptions.GetCount)
qOptions.TotalRecordsCount = feedback.Count();
feedback = feedback.OrderBy(string.IsNullOrWhiteSpace(qOptions.Sort) ? nameof(eFeedback.CreatedDate) : qOptions.Sort)
.Skip(qOptions.Skip)
.Take(qOptions.PageSize);
return _mapper.Map<IEnumerable<eFeedback>, IEnumerable<mFeedback>>(feedback.ToList());
}
}
The current code i have is shown above. This produces 2 hits on the DB. Is there a better approach?
Thanks in advance
I have found a few articles like this one:
http://devtoolshed.com/using-stored-procedures-entity-framework-scalar-return-values
Yet when I take the step to create a function import for a int32 scalar, this is what gets generated:
public ObjectResult<Nullable<global::System.Int32>> MyStoredProcedure(Nullable<global::System.Int32> orderId)
{
ObjectParameter orderIdParameter;
if (orderId.HasValue)
{
orderIdParameter = new ObjectParameter("OrderId", orderId);
}
else
{
orderIdParameter = new ObjectParameter("OrderId", typeof(global::System.Int32));
}
return base.ExecuteFunction<Nullable<global::System.Int32>>("MyStoredProcedure", orderIdParameter);
}
I am able to call the procedure with this, but am not able to get to the underlying scalar:
ObjectResult<int?> result = myEntities.MyProcedure(orderId);
In the code examples I have seen, I should get context.MyProcedure().SingleOrDefault().
Try this:
int? result = myEntities.MyProcedure(orderId).FirstOrDefault();
i have an app which has btn to preview report made in crystal report. I added Dataset as datasource of the report and dragged datatable from the toolbox and added the fields I need as columns. I got the instruction from this link http://aspalliance.com/2049_Use_LINQ_to_Retrieve_Data_for_Your_Crystal_Reports.2. This is my 2nd report the first one works and did not encounter any prob at all that is why i am confused, not to mention it also has nullable column. the error says: DataSet does not support System.Nullable<>.
private void ShowReportView()
{
string reportFile = "JudgeInfoFMReport.rpt";
ObservableCollection<tblJudgeFileMaint> judgeFileMaintList;
judgeFileMaintList = GenerateReport();
if (judgeFileMaintList.Count > 0)
{
CrystalReportViewerUC crview2 = new CrystalReportViewerUC();
crview2.SetReportPathFile(reportFile, judgeFileMaintList);
crview2.ShowDialog();
}
else
{
System.Windows.MessageBox.Show("No record found.", module, MessageBoxButton.OK, MessageBoxImage.Information);
}
}
private ObservableCollection<tblJudgeFileMaint> GenerateReport()
{
var result = FileMaintenanceBusiness.Instance.GetAllJudgeInfoList();
return new ObservableCollection<tblJudgeFileMaint>(result);
}
The error is in the part where I set datasource report.SetDataSource
public bool SetReportPathFile(string reportPathFile, IEnumerable enumerable)
{
string reportFolder = #"\CrystalReportViewer\Reports\";
string filename = System.Windows.Forms.Application.StartupPath + reportFolder + reportPathFile; // "\\Reports\\CrystalReports\\DateWiseEmployeeInfoReport.rpt";
ReportPathFile = filename;
report.Load(ReportPathFile);
report.SetDataSource(enumerable);
report.SetDatabaseLogon("sa", "admin007");
bRet = true;
}
_IsLoaded = bRet;
return bRet;
}
I read some answers and says I should set the null value to DBNUll which I did in the properties window of each column if it is nullable. Can anyone help me please? thanks
Your question can be seen in this post, but in a generic way ... that way you can pass an Object to a DataSet typed!
.NET - Convert Generic Collection to DataTable
figured it out. by using a collectionextention, copied somewhere, I forgot the link. Os to whoever it is who made the class, credits to you.
class method looks like this.
public statis class CollectionExtension {
public static DataSet ToDataSet<T>(this IEnumerable<T> collection, string dataTableName)
{
if (collection == null)
{
throw new ArgumentNullException("collection");
}
if (string.IsNullOrEmpty(dataTableName))
{
throw new ArgumentNullException("dataTableName");
}
DataSet data = new DataSet("NewDataSet");
data.Tables.Add(FillDataTable(dataTableName, collection));
return data;
}
}
then you can use it by doing this in getting your source to your report:
private DataSet GenerateNeutralContEducReport(string dsName)
{
var contEduHistoryList = FileMaintenanceBusiness.Instance.GetManyNeutralFMContEducHistoryInfobyKeyword(CurrentNeutralFM.NeutralID, "NeutralID").ToList();
return CollectionExtensions.ToDataSet<tblContinuingEducationHistory>(contEduHistoryList, dsName);
}
I found little help from the other proposed answers but this solution worked.
A different way to solve this problem is to make the data column nullable.
DataColumn column = new DataColumn("column", Type.GetType("System.Int32"));
column.AllowDBNull = true;
dataTable.Columns.Add(column);
https://learn.microsoft.com/en-us/dotnet/api/system.data.datacolumn.allowdbnull?view=netcore-3.1
foreach (PropertyDescriptor property in properties)
{
dt.Columns.Add(property.Name, Nullable.GetUnderlyingType(property.PropertyType) ?? property.PropertyType);
}
Ok, I must be working too hard because I can't get my head around what it takes to use the Entity Framework correctly.
Here is what I am trying to do:
I have two tables: HeaderTable and DetailTable. The DetailTable will have 1 to Many records for each row in HeaderTable. In my EDM I set up a Relationship between these two tables to reflect this.
Since there is now a relationship setup between these tables, I thought that by quering all the records in HeaderTable, I would be able to access the DetailTable collection created by the EDM (I can see the property when quering, but it's null).
Here is my query (this is a Silverlight app, so I am using the DomainContext on the client):
// myContext is instatiated with class scope
EntityQuery<Project> query = _myContext.GetHeadersQuery();
_myContext.Load<Project>(query);
Since these calls are asynchronous, I check the values after the callback has completed. When checking the value of _myContext.HeaderTable I have all the rows expected. However, the DetailsTable property within _myContext.HeaderTable is empty.
foreach (var h in _myContext.HeaderTable) // Has records
{
foreach (var d in h.DetailTable) // No records
{
string test = d.Description;
}
I'm assuming my query to return all HeaderTable objects needs to be modified to somehow return all the HeaderDetail collectoins for each HeaderTable row. I just don't understand how this non-logical modeling stuff works yet.
What am I doing wrong? Any help is greatly appriciated. If you need more information, just let me know. I will be happy to provide anything you need.
Thanks,
-Scott
What you're probably missing is the Include(), which I think is out of scope of the code you provided.
Check out this cool video; it explained everything about EDM and Linq-to-Entities to me:
http://msdn.microsoft.com/en-us/data/ff628210.aspx
In case you can't view video now, check out this piece of code I have based on those videos (sorry it's not in Silverlight, but it's the same basic idea, I hope).
The retrieval:
public List<Story> GetAllStories()
{
return context.Stories.Include("User").Include("StoryComments").Where(s => s.HostID == CurrentHost.ID).ToList();
}
Loading the the data:
private void LoadAllStories()
{
lvwStories.DataSource = TEContext.GetAllStories();
lvwStories.DataBind();
}
Using the data:
protected void lvwStories_ItemDataBound(object sender, ListViewItemEventArgs e)
{
if (e.Item.ItemType == ListViewItemType.DataItem)
{
Story story = e.Item.DataItem as Story;
// blah blah blah....
hlStory.Text = story.Title;
hlStory.NavigateUrl = "StoryView.aspx?id=" + story.ID;
lblStoryCommentCount.Text = "(" + story.StoryComments.Count.ToString() + " comment" + (story.StoryComments.Count > 1 ? "s" : "") + ")";
lblStoryBody.Text = story.Body;
lblStoryUser.Text = story.User.Username;
lblStoryDTS.Text = story.AddedDTS.ToShortTimeString();
}
}