併發衝突：UpdateCommand影響了預期的1條記錄中的0 0

Question

這裏是代碼，爲什麼我得到這個錯誤的任何想法？

private SQLiteDataAdapter DA_Webfiles; 
// Setup connection, fill dataset etc 

DataTable dt = this.dataSet.Tables["WEBFILES"]; 
DataRow newRow = dt.NewRow(); 
newRow["PATH"] = _url; 
dt.Rows.Add(newRow); 
this.DA_Webfiles.Update(this.dataSet, "WEBFILES"); 
// Works to Here 

newRow["CONTENT_TYPE"] = "Test Content Type"; 
this.DA_Webfiles.Update(this.dataSet, "WEBFILES"); 
// Get ERROR here - Concurrency violation: the UpdateCommand affected 0 of the expected 1 records 

Answer 1

您需要：dataAdapter.InsertCommand.UpdatedRowSource = UpdateRowSource.FirstReturnedRecord;

了代碼的線索在這裏：Retrieving Identity or Autonumber Values (ADO.NET)

表：

CREATE TABLE [emp] (
[emp_id] INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, 
[emp_firstname] VARCHAR(100) NOT NULL, 
[emp_lastname] varchar(100) not null 
) 

代碼：

public partial class Form1 : Form 
{ 
    public Form1() 
    { 
     InitializeComponent(); 


     var c = Connect(); 

     var da = new SQLiteDataAdapter("select emp_id, emp_firstname, emp_lastname from emp where 1 = 0", c); 



     var b = new SQLiteCommandBuilder(da); 

     da.InsertCommand = new SQLiteCommand(
      @"insert into emp(emp_firstname, emp_lastname) values(:_emp_firstname, :_emp_lastname); 
      select emp_id /* include rowversion field here if you need */ from emp where emp_id = last_insert_rowid();", c); 
     da.InsertCommand.Parameters.Add("_emp_firstname", DbType.String, 0, "emp_firstname"); 
     da.InsertCommand.Parameters.Add("_emp_lastname", DbType.String, 0, "emp_lastname"); 
     da.InsertCommand.UpdatedRowSource = UpdateRowSource.FirstReturnedRecord; 

     da.UpdateCommand = b.GetUpdateCommand(); 
     da.DeleteCommand = b.GetDeleteCommand(); 


     var dt = new DataTable(); 
     da.Fill(dt); 

     var nr = dt.NewRow(); 
     nr["emp_firstname"] = "john"; 
     nr["emp_lastname"] = "lennon"; 

     dt.Rows.Add(nr); 

     da.Update(dt); 

     dt.AcceptChanges(); 

     nr["emp_lastname"] = "valjean"; 
     da.Update(dt); 

    } 

    SQLiteConnection Connect() 
    { 
     return new SQLiteConnection(@"Data Source=../../test.s3db;Version=3;"); 
    } 
} 

上面的代碼工作在多插了。驗證的概念代碼：

public partial class Form1 : Form 
{ 
    public Form1() 
    { 
     InitializeComponent(); 


     var c = Connect(); 

     var da = new SQLiteDataAdapter("select emp_id, emp_firstname, emp_lastname from emp where 1 = 0", c); 



     var b = new SQLiteCommandBuilder(da); 

     da.InsertCommand = new SQLiteCommand(
      @"insert into emp(emp_firstname, emp_lastname) values(:_emp_firstname, :_emp_lastname); 
      select emp_id /* include rowversion field here if you need */ from emp where emp_id = last_insert_rowid();", c); 
     da.InsertCommand.Parameters.Add("_emp_firstname", DbType.String, 0, "emp_firstname"); 
     da.InsertCommand.Parameters.Add("_emp_lastname", DbType.String, 0, "emp_lastname"); 
     da.InsertCommand.UpdatedRowSource = UpdateRowSource.FirstReturnedRecord; 

     da.UpdateCommand = b.GetUpdateCommand(); 
     da.DeleteCommand = b.GetDeleteCommand(); 


     var dt = new DataTable(); 
     da.Fill(dt); 

     var nr = dt.NewRow(); 
     nr["emp_firstname"] = "john"; 
     nr["emp_lastname"] = "lennon"; 


     var nrx = dt.NewRow(); 
     nrx["emp_firstname"] = "paul"; 
     nrx["emp_lastname"] = "mccartney"; 


     dt.Rows.Add(nr); 
     dt.Rows.Add(nrx); 

     da.Update(dt); 

     dt.AcceptChanges(); 


     nrx["emp_lastname"] = "simon"; 
     da.Update(dt); 

     nr["emp_lastname"] = "valjean"; 
     da.Update(dt); 

    } 

    SQLiteConnection Connect() 
    { 
     return new SQLiteConnection(@"Data Source=../../test.s3db;Version=3;"); 
    } 
}