[英]How to add and access connection string from web.config
我想添加连接字符串以连接到web.config文件中定义的mysql并访问我的C#代码中的相同连接我该怎么办?
这是我的代码示例,在单击按钮以连接到数据库之后运行。
protected void Button2_Click(object sender, EventArgs e)
{
String a = DropDownList1.SelectedItem.Value;
String b = DropDownList3.SelectedItem.Value.PadLeft(3, '0');
String c = TextBox2.Text.PadLeft(5,'0').ToString();
String d = TextBox3.Text.ToString();
String digit = a+ b + c + d;
try
{
myConn = new OdbcConnection("Driver={MySQL ODBC 3.51 Driver};Server=localhost;Database=testcase;User=root;Password=root;Option=3;");
myConn.Open();
//**
string sql = "select * from testcase.main where reg_no =?";
//**
OdbcCommand cmd = new OdbcCommand(sql, myConn);
//**
cmd.Parameters.AddWithValue("?", digit);
MyReader = cmd.ExecuteReader();
//**
while (MyReader.Read())
{
String f = MyReader["pet_name"].ToString();
String g = MyReader["res_name"].ToString();
Label9.Visible = true;
Label9.Text = f;
Label10.Visible = true;
Label10.Text = "VS";
//Label11.Visible = true;
Label11.Text = g;
}
MyReader.Close();
}
catch (Exception e1)
{
Response.Write(e1.ToString());
}
finally
{
if (MyReader != null && !MyReader.IsClosed)
{
MyReader.Close();
}
if (myConn != null && myConn.State == ConnectionState.Open)
{
myConn.Close();
}
}
如果您知道连接字符串名称,则可以使用ConfigurationManager
类的ConnectionStrings属性
例如
using System.Configuration;
string ConnectionString = ConfigurationManager.ConnectionStrings["ConnectionStringName"].ConnectionString.ToString();
其中,您的web.config将包含名为ConnectionStringName
的连接ConnectionStringName
下面是为SQL Server创建和添加connectionString到web.config的示例,您可以将sql连接更改为OleDb连接
SqlConnectionStringBuilder connectionStringBuilder = new SqlConnectionStringBuilder();
connectionStringBuilder.DataSource = "localhost";
connectionStringBuilder.IntegratedSecurity = true;
connectionStringBuilder.InitialCatalog = "SampleDB";
ConnectionStringSettings connSttng = new ConnectionStringSettings();
connSttng.Name = "ConnectionStringName";
connSttng.ProviderName = "Providername";
connSttng.ConnectionString = String.Format("DataSource={0};InitialCatalog={1};IntegratedSecurity={2}", connectionStringBuilder.DataSource, connectionStringBuilder.InitialCatalog, connectionStringBuilder.IntegratedSecurity);
Configuration config = WebConfigurationManager.OpenWebConfiguration("~");
config.ConnectionStrings.ConnectionStrings.Add(connSttng);
config.Save(ConfigurationSaveMode.Modified, true);
ConfigurationManager.RefreshSection("connectionStrings");
希望这将是充分利用
在web配置中:
<connectionStrings>
<add
name="NorthwindConnectionString"
connectionString="Data Source=serverName;Initial
Catalog=Northwind;Persist Security Info=True;User
ID=userName;Password=password"
providerName="System.Data.SqlClient"/>
</connectionStrings>
在视图中:
using System.Configuration;
string ConnectionString =ConfigurationManager.ConnectionStrings["NorthwindConnectionString"].ConnectionString.ToString();
在所有这些答案中, static
缺失
导入此命名空间:
using System.Configuration;
获取连接字符串:
static string ConnectionString = ConfigurationManager.ConnectionStrings["ConnectionStringName"].ConnectionString.ToString();
网络配置
<connectionStrings>
<add name="cn"connectionString="server=localhost;database=database_name;uid=username;password=your password"/>
</connectionStrings>
aspx页面
string constr=ConfigurationManager.ConnectionStrings["cn"].ConnectionString;
MySqlConnection con = new MySqlConnection(constr);
MySqlCommand cmd =new MySqlCommand("select * from tbl_mastercampaign", con);
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