Question

以下代码中缺少什么？在这段代码片段中，我正在从SQLite数据库中读取一个表。然后我更新一个单元格，然后回读更改。

此代码是较大代码的简化版本，但它说明了问题。

代码完全读取表，但AcceptChanges（）不会写回任何内容。我通过重复阅读并转到SQLiteAdmin并仔细阅读表来验证它。

我尝试添加“oLocalAdapter.Update（oLocalSet.Tables [0]）;”然而，这并没有任何区别。我看到了进行搜索。

using System.Data.SQLite;

// DATABASE (Local): Formulate the SQL command.
String strSqlCommand = "SELECT * FROM [tblTest] ORDER BY [IdPrimary] ASC;";
SQLiteCommand oLocalCommand = new SQLiteCommand(strSqlCommand, ClassEngine.Connection);

// DATABASE (Local): Get the data records.
SQLiteDataAdapter oLocalAdapter = new SQLiteDataAdapter(oLocalCommand);
DataSet oLocalSet = new DataSet();
oLocalAdapter.Fill(oLocalSet, "tblTest");

// Try to write to some changes.
String strValue = oLocalSet.Tables[0].Rows[0][8].ToString();
oLocalSet.Tables[0].Rows[0][8] = 9;
oLocalSet.Tables[0].AcceptChanges();
oLocalAdapter.Update(oLocalSet.Tables[0]);

// Clean up.
oLocalSet.Dispose();
oLocalAdapter.Dispose();
oLocalCommand.Dispose();
oLocalCommand = null;

Answer 1

好的，明白了。

一，我必须重新定位/修改AcceptChanges（）行。

包括可能的行

oLocalAdapter.AcceptChangesDuringUpdate = true;

然后我必须加入

SQLiteCommandBuilder oBuilder = new SQLiteCommandBuilder(oLocalAdapter);
oLocalAdapter.UpdateCommand = oBuilder.GetUpdateCommand();

最后一行是更新，它可以工作。这就是代码：

// DATABASE (Local): Formulate the SQL command.
String strSqlCommand = "SELECT * FROM tblTest ORDER BY IdPrimary ASC;";
SQLiteCommand oLocalCommand = new SQLiteCommand(strSqlCommand, ClassEngine.Connection);

// DATABASE (Local): Get the data records.
SQLiteDataAdapter oLocalAdapter = new SQLiteDataAdapter(oLocalCommand);
DataSet oLocalSet = new DataSet();
oLocalAdapter.Fill(oLocalSet, "tblTest");

// 
SQLiteCommandBuilder oBuilder = new SQLiteCommandBuilder(oLocalAdapter);

// Try to write to some changes.
String strValue = oLocalSet.Tables[0].Rows[0][8].ToString();
oLocalSet.Tables[0].Rows[0][8] = 9;
strValue = oLocalSet.Tables[0].Rows[0][8].ToString();
oLocalSet.AcceptChanges();
oLocalAdapter.UpdateCommand = oBuilder.GetUpdateCommand();
oLocalAdapter.Update(oLocalSet.Tables[0]);

// Clean up.
oLocalSet.Dispose();
oLocalAdapter.Dispose();
oLocalCommand.Dispose();
oLocalCommand = null;

Answer 2

public void SaveDataTable(DataTable DT)
        {
        try
            {
            con.Open();
            cmd = con.CreateCommand();
            cmd.CommandText = string.Format("SELECT * FROM {0}", DT.TableName);
            adapter = new SQLiteDataAdapter(cmd);
            SQLiteCommandBuilder builder = new SQLiteCommandBuilder(adapter);
            adapter.Update(DT);
            con.Close();
            }
        catch (Exception Ex)
            {
            System.Windows.MessageBox.Show(Ex.Message);
            }

使用SqliteDataAdapter将更改写入SQLite数据库

2 个答案: