我創建了與Microsoft SQL數據庫的連接,並試圖在練習中添加基本信息,但出現以下錯誤。未將對象引用設置爲將數據插入數據庫的對象實例
Object reference not set to an instance of an object
這是我如何連接到數據庫
SqlConnection sqlConn;
protected void butConnect_Click(object sender, EventArgs e)
{
try
{
string connectionString = "Data Source=.\\SQLEXPRESS;Initial Catalog=lrmg;Integrated Security=True;";
sqlConn = new SqlConnection(connectionString);
sqlConn.Open();
labMessage.Text = "a connection to your database was established";
}
catch (SqlException sqlE)
{
labMessage.Text = sqlE.Message;
}
catch (Exception exe)
{
labMessage.Text = exe.Message;
}
這裏是我的錯誤
protected void butSubmit_Click(object sender, EventArgs e)
{
try
{
string name = txtName.Text;
string date = txtDate.Text;
**SqlCommand cmd = sqlConn.CreateCommand();**
cmd.CommandText = "INSERT INTO Canditate(Name, Doj) VALUES('" + name + "'," + date + ")";
cmd.ExecuteNonQuery();
labMessage.Text = "The value was inserted into your database";
}
catch (SqlException sqlE)
{
labMessage.Text = sqlE.Message;
}
catch (Exception exe)
{
labMessage.Text = exe.Message;
}
}
我的印象是SQL連接被打開,以便下爲什麼是異常?
你試過了什麼?沒有將對象引用設置爲對象的實例意味着「NULL」使用調試器! – Nahum
+1。是。如果這是一個優先級,那麼學習編程 - 並使用調試器來發現這一點非常重要。打破異常,看看什麼變量LS空。用你的大腦(是的,你有)找出原因。併爲你的SQL使用參數。 – TomTom
檢查您的連接字符串,創建sqlconnection對象並逐步查看它是否正確初始化。 – nik0lias