Question

C#如何访问Access数据库

急。
无论使用ODBC ADO.net……

至少包括四段源代码：
1#连接
2#如何从一个表中取得数据
3#如何向一张表插入一段数据
4#如何修改某张表某条数据某个字段上的值

我提供一个数据表的模型（可以不参照）
表名：User
字段:ID,UserName,UserPassword

如果能在一天内回答再加分。

Answer 1

// 连接
OleDbConnection cn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Data Source=C:\\test.mdb;");
cn.Open();
cn.Close();

// 读取数据到DataTable
OleDbConnection cn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Data Source=C:\\test.mdb;");
DataTable userTbl = new DataTable();
OleDbDataAdapter da = new OleDbDataAdapter("SELECT * FROM [User]", cn);
da.Fill(userTbl);

// 插入一条记录
OleDbConnection cn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Data Source=C:\\test.mdb;");
OleDbCommand cmd = new OleDbCommand("INSERT INTO [User] ([ID], [UserName], [UserPassword]) VALUES (1, 'user_ab', '123')", cn);

cn.Open();
cmd.ExecuteNonQuery();
cn.Close();

// 更新
OleDbConnection cn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Data Source=C:\\test.mdb;");
OleDbCommand cmd = new OleDbCommand("UPDATE [User] SET [UserPassword]='newpwd' WHERE [UserName]='user_ab'", cn);

cn.Open();
cmd.ExecuteNonQuery();
cn.Close();

Answer 2

// 连接
OleDbConnection cn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Data Source=C:\\test.mdb;");
cn.Open();
cn.Close();

// 读取数据到DataTable
OleDbConnection cn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Data Source=C:\\test.mdb;");
DataTable userTbl = new DataTable();
OleDbDataAdapter da = new OleDbDataAdapter("SELECT * FROM [User]", cn);
da.Fill(userTbl);

// 插入一条记录
OleDbConnection cn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Data Source=C:\\test.mdb;");
OleDbCommand cmd = new OleDbCommand("INSERT INTO [User] ([ID], [UserName], [UserPassword]) VALUES (1, 'user_ab', '123')", cn);

cn.Open();
cmd.ExecuteNonQuery();
cn.Close();

// 更新
OleDbConnection cn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Data Source=C:\\test.mdb;");
OleDbCommand cmd = new OleDbCommand("UPDATE [User] SET [UserPassword]='newpwd' WHERE [UserName]='user_ab'", cn);

cn.Open();
cmd.ExecuteNonQuery();
cn.Close();