DataBase Accessing in C# with ASP.Net problem

rock pora

Well-known member
  • May 18, 2011
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    ###~.:::.සියනෑ කෝරළේ.::.~##
    macho table ekak thiyenava SOH kiyala.newEntities kiyala Entity ekak thiyenava
    mn SOH kiyana table eke thiyena data okkoma list ekakata gannava me vidiyata

    using (newEntities db = new newEntities())
    {
    List<SOH> soh = (from x in db.SOHs select x).ToList();

    }

    Q1)mehema gaththama table eke thiyena row gaana balaganne kohomada bn??
    (soh.Count() eken rows gana ganna bane bn)

    Q2)Table eke anthimata insert karapu row eke column ekaka value eka ganne kohomada bn??

    updated.table names venas kala.mage thiyena vidiyatama damma :)

    Q3) thava prashnayak thiyenava :D

    okkoma tables 3k thiyenava.SOH,SOD,Item kiyala.

    button 1k press kalama,
    SOH table ekata record ekak yanava.

    ita passe SOH eken gannava last record eke SoNo(SOH,SOD dekema primary key valata thiyenne same name) eka.
    ita passe SOD table ekata record ekak yavanna one ara SOH eken gaththa SoNo ekai Item table eke INo th ekka.
    me SOD ekata samahara velavata records godak vatenava.e hama record ekatama SOH eken gaththa SoNo value eka ekamai,INo eka venas venava.

    awla thiyenne SOH ekata record eka yanava SOD ekata yanne na :(

    me thiyenne SOH tabe eke design veiw eka
    meka primary key eka Auto increment venava
    rW6k7ac.png


    me thiyenne Item kiyana table eke design view eka
    meketh primary key eka Auto increment venava
    1amGVWi.png


    me thiyenne SOD kiyana table eke design view eka
    meke primary key eka Auto increment venne na
    E33ojaa.png



    mata list ekakatama ganna one bn table eke data tika.var valata aragena ba.e vidiyata ganna hati EK membersla yata kiyala thiyenava

    danne nathnam bump ekak hari dala yannakooo
     
    Last edited:
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    chirart1

    Well-known member
  • Jul 27, 2009
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    products.Count() eken ayi enne naththe :O
    enna epai ban :(
    last insert eka gannath wenne ohoma count eka gaththa eke anthima index eken access karanna puluwan ne :D
    column access karanne products["column_name"] mehema kiyalai mathaka lagadi kare na :D heheh
    .count() eken mokadda ubata enne ?
     
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    shalinds

    Active member
  • Dec 10, 2014
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    using (newEntities db = new newEntities())
    {
    List<Product> products = db.Products.ToList();

    }

    Q1.

    products.Count()

    Q2. To get the last record of the list

    using (newEntities db = new newEntities())
    {
    Product product = db.Products.LastOrDefault();
    }

    Q3. To get the Id(or any other column) of the recently inserted record

    using (var context = new newEntities())
    {
    context.MyEntities.AddObject(myNewObject);
    context.SaveChanges();

    int id = myNewObject.Id;
    }


    http://www.entityframeworktutorial.net/
     
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    shamRox

    Well-known member
  • May 25, 2011
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    var selectList=db.Products.ToList();

    //Take Count
    int count=selectList.Count();

    // Take Lat inserted row
    var lastItem=db.Products.OrderbyDecending(o=>o.ID).FirstOrDefault(); //last inserted row

    int lastid=lastItem.ID; // Last Inserted ID(can take all columns using this object)

    last kiyala tiyena eka teune na...
     
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    rock pora

    Well-known member
  • May 18, 2011
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    ###~.:::.සියනෑ කෝරළේ.::.~##
    products.Count() eken ayi enne naththe :O
    enna epai ban :(
    last insert eka gannath wenne ohoma count eka gaththa eke anthima index eken access karanna puluwan ne :D
    column access karanne products["column_name"] mehema kiyalai mathaka lagadi kare na :D heheh
    .count() eken mokadda ubata enne ?
    macho count dammama 0 kiyala bn enne.eth table eke rows thiyena 5kma :(


    ITP karana gaman da?
    bump thamai
    ITP kiyanne mokadda bn? :D


    using (newEntities db = new newEntities())
    {
    List<Product> products = db.Products.ToList();

    }

    Q1.

    products.Count()

    Q2. To get the last record of the list

    using (newEntities db = new newEntities())
    {
    Product product = db.Products.LastOrDefault();
    }

    Q3. To get the Id(or any other column) of the recently inserted record

    using (var context = new newEntities())
    {
    context.MyEntities.AddObject(myNewObject);
    context.SaveChanges();

    int id = myNewObject.Id;
    }


    http://www.entityframeworktutorial.net/

    Q1.db.Products.ToList(); mehema dala products.Count() dammath rows gana 0 kiyalane bn enne :(

    Q2. Product products =db.products.LastOrDefault(); dila
    products.columnName eka return kala.eth eke value eka 0 kiyalane enne :(

    Q3. mekanm therune na bn :D

    var selectList=db.Products.ToList();

    //Take Count
    int count=selectList.Count();

    // Take Lat inserted row
    var lastItem=db.Products.OrderbyDecending(o=>o.ID).FirstOrDefault(); //last inserted row

    int lastid=lastItem.ID; // Last Inserted ID(can take all columns using this object)

    last kiyala tiyena eka teune na...
    Count vena eka hari bn :D

    anthima row value ekanm ganna ba bn :(

    var lastItem = db.Products.OrderByDescending(o => o.SoNo).LastOrDefault();
    int Id = lastItem.SoNo;
    return Id;

    0 kiyalane bn enne :(
    rows gananam count venava bn
     

    rock pora

    Well-known member
  • May 18, 2011
    11,951
    2,791
    113
    ###~.:::.සියනෑ කෝරළේ.::.~##
    var productList = db.Products.ToList();

    var productCount = productList.Count;

    var lastRow = productList[productCount-1]
    macho me vidiyata vada bn :)
    uba danne nadda list ekakata data tika load karanna??


    Q3) thava prashnayak thiyenava :D

    okkoma tables 3k thiyenava.SOH,SOD,Item kiyala.

    button 1k press kalama,
    SOH table ekata record ekak yanava.

    ita passe SOH eken gannava last record eke SoNo(SOH,SOD dekema primary key valata thiyenne same name) eka.
    ita passe SOD table ekata record ekak yavanna one ara SOH eken gaththa SoNo ekai Item table eke INo th ekka.
    me SOD ekata samahara velavata records godak vatenava.e hama record ekatama SOH eken gaththa SoNo value eka ekamai,INo eka venas venava.

    awla thiyenne SOH ekata record eka yanava SOD ekata yanne na :(

    me thiyenne SOH tabe eke design veiw eka
    meka primary key eka Auto increment venava
    rW6k7ac.png


    me thiyenne Item kiyana table eke design view eka
    meketh primary key eka Auto increment venava
    1amGVWi.png


    me thiyenne SOD kiyana table eke design view eka
    meke primary key eka Auto increment venne na
    E33ojaa.png

     

    dildude

    Member
    May 27, 2015
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    🅷🅴🅰V🅴🅽
    Balanna SOD table eke SoNO ekai, INO ekai duplicate wenawada kiyala. Ehema unoth insert wenne na.
    Table design ekata access thiyanawa nam SOD table ekata wenama primary key ekak danna SodNO kiyala. eeta passe SoNo ekai, INO ekai foreign key danna.
     

    rock pora

    Well-known member
  • May 18, 2011
    11,951
    2,791
    113
    ###~.:::.සියනෑ කෝරළේ.::.~##
    Balanna SOD table eke SoNO ekai, INO ekai duplicate wenawada kiyala. Ehema unoth insert wenne na.
    Table design ekata access thiyanawa nam SOD table ekata wenama primary key ekak danna SodNO kiyala. eeta passe SoNo ekai, INO ekai foreign key danna.
    na bn.mn thani record ekak dalath baluva.e yanneth na :(
    macho ehema venama primary key ekak dammoth nam me vade hariyai samahara vita,eth bn data redundancy venava neda ehema kalama
    ethakota ape lakunu kaanava bn :(
     

    rock pora

    Well-known member
  • May 18, 2011
    11,951
    2,791
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    ###~.:::.සියනෑ කෝරළේ.::.~##
    menna error eka
    System.Data.Entity.Infrastructure.DbUpdateException: An error occurred while updating the entries. See the inner exception for details. ---> System.Data.Entity.Core.UpdateException: An error occurred while updating the entries. See the inner exception for details. ---> System.InvalidOperationException: A dependent property in a ReferentialConstraint is mapped to a store-generated column. Column: 'SoNo'. at System.Data.Entity.Core.Mapping.Update.Internal.UpdateCompiler.BuildSetClauses(DbExpressionBinding target, PropagatorResult row, PropagatorResult originalRow, TableChangeProcessor processor, Boolean insertMode, Dictionary`2& outputIdentifiers, DbExpression& returning, Boolean& rowMustBeTouched) at System.Data.Entity.Core.Mapping.Update.Internal.UpdateCompiler.BuildInsertCommand(PropagatorResult newRow, TableChangeProcessor processor) at System.Data.Entity.Core.Mapping.Update.Internal.TableChangeProcessor.CompileCommands(ChangeNode changeNode, UpdateCompiler compiler) --- End of inner exception stack trace --- at System.Data.Entity.Core.Mapping.Update.Internal.TableChangeProcessor.CompileCommands(ChangeNode changeNode, UpdateCompiler compiler) at System.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator.d__a.MoveNext() at System.Linq.Enumerable.d__71`1.MoveNext() at System.Data.Entity.Core.Mapping.Update.Internal.UpdateCommandOrderer..ctor(IEnumerable`1 commands, UpdateTranslator translator) at System.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator.ProduceCommands() at System.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator.Update() at System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.b__2(UpdateTranslator ut) at System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.Update[T](T noChangesResult, Func`2 updateFunction) at System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.Update() at System.Data.Entity.Core.Objects.ObjectContext.b__35() at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess) at System.Data.Entity.Core.Objects.ObjectContext.SaveChangesToStore(SaveOptions options, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction) at System.Data.Entity.Core.Objects.ObjectContext.<>c__DisplayClass2a.b__27() at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1 operation) at System.Data.Entity.Core.Objects.ObjectContext.SaveChangesInternal(SaveOptions options, Boolean executeInExistingTransaction) at System.Data.Entity.Core.Objects.ObjectContext.SaveChanges(SaveOptions options) at System.Data.Entity.Internal.InternalContext.SaveChanges() --- End of inner exception stack trace --- at System.Data.Entity.Internal.InternalContext.SaveChanges() at System.Data.Entity.Internal.LazyInternalContext.SaveChanges() at System.Data.Entity.DbContext.SaveChanges() at SODModel.InsertSOD(SOD sOD) in c:\Users\Administrator\Documents\Visual Studio 2013\WebSites\BookShop\App_Code\Models\SODModel.cs:line 17
     

    Thilantdm

    Well-known member
  • Sep 15, 2010
    22,596
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    අද නම් හදට ආවා
    menna error eka
    System.Data.Entity.Infrastructure.DbUpdateException: An error occurred while updating the entries. See the inner exception for details. ---> System.Data.Entity.Core.UpdateException: An error occurred while updating the entries. See the inner exception for details. ---> System.InvalidOperationException: A dependent property in a ReferentialConstraint is mapped to a store-generated column. Column: 'SoNo'. at System.Data.Entity.Core.Mapping.Update.Internal.UpdateCompiler.BuildSetClauses(DbExpressionBinding target, PropagatorResult row, PropagatorResult originalRow, TableChangeProcessor processor, Boolean insertMode, Dictionary`2& outputIdentifiers, DbExpression& returning, Boolean& rowMustBeTouched) at System.Data.Entity.Core.Mapping.Update.Internal.UpdateCompiler.BuildInsertCommand(PropagatorResult newRow, TableChangeProcessor processor) at System.Data.Entity.Core.Mapping.Update.Internal.TableChangeProcessor.CompileCommands(ChangeNode changeNode, UpdateCompiler compiler) --- End of inner exception stack trace --- at System.Data.Entity.Core.Mapping.Update.Internal.TableChangeProcessor.CompileCommands(ChangeNode changeNode, UpdateCompiler compiler) at System.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator.d__a.MoveNext() at System.Linq.Enumerable.d__71`1.MoveNext() at System.Data.Entity.Core.Mapping.Update.Internal.UpdateCommandOrderer..ctor(IEnumerable`1 commands, UpdateTranslator translator) at System.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator.ProduceCommands() at System.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator.Update() at System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.b__2(UpdateTranslator ut) at System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.Update[T](T noChangesResult, Func`2 updateFunction) at System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.Update() at System.Data.Entity.Core.Objects.ObjectContext.b__35() at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess) at System.Data.Entity.Core.Objects.ObjectContext.SaveChangesToStore(SaveOptions options, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction) at System.Data.Entity.Core.Objects.ObjectContext.<>c__DisplayClass2a.b__27() at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1 operation) at System.Data.Entity.Core.Objects.ObjectContext.SaveChangesInternal(SaveOptions options, Boolean executeInExistingTransaction) at System.Data.Entity.Core.Objects.ObjectContext.SaveChanges(SaveOptions options) at System.Data.Entity.Internal.InternalContext.SaveChanges() --- End of inner exception stack trace --- at System.Data.Entity.Internal.InternalContext.SaveChanges() at System.Data.Entity.Internal.LazyInternalContext.SaveChanges() at System.Data.Entity.DbContext.SaveChanges() at SODModel.InsertSOD(SOD sOD) in c:\Users\Administrator\Documents\Visual Studio 2013\WebSites\BookShop\App_Code\Models\SODModel.cs:line 17

    meke inner exepcition blpn :D