如何正確初始化.NET OleDbConnection對象及其ConnectionString屬性？

Question

這是我的C＃代碼來連接和使用Access數據庫。

using System.Data.OleDb; 

var cb = new OleDbCommandBuilder(da); 

DataRow dRow = ds1.Tables["Customer"].NewRow(); 

dRow[0] = textBox1.Text; 
dRow[1] = textBox2.Text; 
dRow[2] = textBox3.Text; 

ds1.Tables["Customer"].Rows.Add(dRow); 

da.Update(ds1, "Customer"); 

con.Close(); 

MessageBox.Show("Entry added"); 

而行da.Update(ds1,"Customer");，拋出一個異常：

ConnectionString屬性尚未初始化。

Answer 1

我並不太在意你的問題，但這裏有一些示例代碼可以幫助你找出你正在嘗試做的任何事情。

爲了清楚起見：數據庫名爲「MyDb.accdb」，並有一個名爲「Customer」的表，其中有兩個字段「Name」和「Phone」。這個例子假設數據庫和可執行文件位於同一個目錄中。

private void AddCustomer(string customerName, string customerPhone) 
{ 
    string name = customerName; 
    string phone = customerPhone; 

    // An easy way to determine the connection string to your database is to open the database from Visual Studio's 'Server Explorer'. 
    // Then, from Server Explorer, view the Properties of the database - in the Properties you will see the "Connection String". 
    // You can/should replace the arbitrary part of the path with "|DataDirectory|". 
    string connString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|MyDb.accdb;Persist Security Info=True"; 

    // Create your sql query in a string variable 
    string cmdText = string.Format("INSERT INTO Customer(Name, Phone) VALUES('{0}','{1}');", name, phone); 

    // Use the 'using' statement on your connection so that the resource is managed properly 
    using (System.Data.OleDb.OleDbConnection connection = new System.Data.OleDb.OleDbConnection(connString)) 
    {     
     // Here's where/how we fire off the INSERT statement 
     OleDbCommand cmd = new OleDbCommand(cmdText, connection); 
     connection.Open(); 
     cmd.ExecuteNonQuery(); 
    } 
}