我正在dataGridView使用表 A 中的数据填充 a，该表属于MySQL数据库表。SaveChangestoDb( string TableName)在插入新数据或修改 DataTable A 的数据后调用该方法时 - 更改正在保存到数据库中，但是当我将批准DataRows从表 A 转移到表 B 然后从表 A 中删除批准的行时...保存对表 A 所做的更改失败。它不会抛出任何异常。
我BindingSource用于将表 A 绑定到 ，dataGridView并CommandBuilder用于获取DataAdapter.
这是我的代码：
private const string ConnectionString =
"server=*****.**;Port=****;database=**;username=****;password=*****;pooling=false;";
private DataSet _localDatabaseCopy;
private MySqlDataAdapter _myDataAdapter;
private void Form1_Load(object sender, System.EventArgs e)
{
InitializeLocalDatabaseCopy();
InitializeDataGridView();
dataGridView1.AllowUserToAddRows = false;
}
/// <summary>
/// Binds the DataGridView to the BindingSource and load the data from the database.
/// </summary>
private void InitializeDataGridView()
{
DataTable dataTable = _localDatabaseCopy.Tables[Resources.WorkingDataDatabaseTableName];
dataGridView1.DataSource = new BindingSource { DataSource = dataTable };
dataGridView1.MultiSelect = true;
dataTable.Columns[Resources.ColumnName_IDNr].AutoIncrement = true;
dataTable.Columns[Resources.ColumnName_IDNr].AutoIncrementSeed = -1;
dataTable.Columns[Resources.ColumnName_IDNr].AutoIncrementStep = -1;
}
/// <summary>
/// Fills the _myDataAdapter DataAdapter with the workingData & approvedData DataTables and adds the 2 DataTables to the _localDatabaseCopy DataSet.
/// </summary>
private void InitializeLocalDatabaseCopy()
{
_localDatabaseCopy = new DataSet();
DataTable workingData = new DataTable(Resources.WorkingDataDatabaseTableName);
DataTable approvedData = new DataTable(Resources.ApprovedDataDatabaseTableName);
using (MySqlConnection connection = new MySqlConnection(ConnectionString))
{
_myDataAdapter = new MySqlDataAdapter(string.Format("select * from {0}", Resources.WorkingDataDatabaseTableName), connection);
_myDataAdapter.Fill(workingData);
_myDataAdapter.SelectCommand.CommandText = string.Format("select * from {0}", Resources.ApprovedDataDatabaseTableName);
_myDataAdapter.Fill(approvedData);
}
_localDatabaseCopy.Tables.Add(workingData);
_localDatabaseCopy.Tables.Add(approvedData);
}
private void SaveChangesToDb(string tableName)
{
MySqlCommandBuilder builder = new MySqlCommandBuilder(_myDataAdapter);
_myDataAdapter.SelectCommand.CommandText = String.Format("select * from {0}", tableName);
_myDataAdapter.UpdateCommand = builder.GetUpdateCommand();
_myDataAdapter.DeleteCommand = builder.GetDeleteCommand();
_myDataAdapter.InsertCommand = builder.GetInsertCommand();
DataTable deletedRecords = _localDatabaseCopy.Tables[tableName].GetChanges(DataRowState.Deleted);
DataTable modifiedRecords = _localDatabaseCopy.Tables[tableName].GetChanges(DataRowState.Modified);
DataTable addedRecords = _localDatabaseCopy.Tables[tableName].GetChanges(DataRowState.Added);
try
{
if (deletedRecords != null)
_myDataAdapter.Update(deletedRecords);
if (modifiedRecords != null)
_myDataAdapter.Update(modifiedRecords);
if (addedRecords != null)
_myDataAdapter.Update(addedRecords);
_localDatabaseCopy.AcceptChanges();
}
catch (Exception exception)
{
MessageBox.Show(exception.Message);
}
finally
{
if (deletedRecords != null)
deletedRecords.Dispose();
if (modifiedRecords != null)
modifiedRecords.Dispose();
if (addedRecords != null)
addedRecords.Dispose();
}
}
private void btnSave_Click(object sender, EventArgs e)
{
SaveChangesToDb(Resources.WorkingDataDatabaseTableName);
}
private void DeleteDataRows(DataRow[] rowsToDelete, string tableIndex)
{
foreach (DataRow row in rowsToDelete)
_localDatabaseCopy.Tables[tableIndex].Rows.Remove(row);
}
/// <summary>
/// Transfers the approved DataRows from the DataTable/DataGridview to the Approved Table in the MySql Database
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void btnTransferApproved_Click(object sender, EventArgs e)
{
SetWaitingCursor();
TransferApprovedDataRows();
DeleteTransferedRowsFromWorkingDataTable();
SaveChangesToDb(Resources.WorkingDataDatabaseTableName);
SetDefaultCursor();
}
private void DeleteTransferedRowsFromWorkingDataTable()
{
DataRow[] approvedRowsToDelete = _localDatabaseCopy.Tables[Resources.WorkingDataDatabaseTableName].Select("Approved = 1");
DeleteDataRows(approvedRowsToDelete, Resources.WorkingDataDatabaseTableName);
}
private void TransferApprovedDataRows()
{
DataTable myTableCopy = _localDatabaseCopy.Tables[Resources.WorkingDataDatabaseTableName].Copy();
DataRow[] approvedRows = myTableCopy.Select("Approved = 1");
// if there are no rows which have been approved, quit
if (approvedRows.Any())
{
foreach (DataRow row in approvedRows)
{
// checking if the row which is to be approved already exists in the approved-table
bool redundant = false;
foreach (
DataRow approvedRow in _localDatabaseCopy.Tables[Resources.ApprovedDataDatabaseTableName].Rows)
redundant |= approvedRow[Resources.ColumnName_IDNr].ToString() ==
row[Resources.ColumnName_IDNr].ToString();
if (!redundant)
_localDatabaseCopy.Tables[Resources.ApprovedDataDatabaseTableName].Rows.Add(row.ItemArray);
}
// writing the changes back to the database, Approved Table
SaveChangesToDb(Resources.ApprovedDataDatabaseTableName);
}
if (!approvedRows.Any())
return;
}
}
}