利用AppConfig文件连接数据库的常用操作

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<connectionStrings>
<add name="NorthwindConnection"
connectionString="server=(local);uid=TestUser;pwd=123456;Trusted_Connection=no;database=Northwind" providerName="System.Data.SqlClient" />
</connectionStrings>
</configuration>

//string connstr = "Data Source = localhost; Initial Catalog = Northwind; User ID =sa; Password =sapass ";

//string connstr = @"Data Source=./SQLEXPRESS;AttachDbFilename=D:/PUBS.MDF;Integrated Security=True;Connect Timeout=30;User Instance=True";

建立上述XML文档后下面就是读取该连接信息

ConnectionStringSettings settings;

settings = ConfigurationManager.ConnectionStrings["NorthwindConnection"];
ConnectionString = settings.ConnectionString;

但是在程序中我们一般编写代码想连接数据库时一般用到下列属性代码

#region Help Property & Method

private string connString = null;
public string ConnString
{
get
{
if (connString == null)
connString = ConfigurationManager.ConnectionStrings["NorthwindConnection"].ConnectionString;

return connString;
}
}

#endregion

这样返回的connString 中就含有字符串连接数据库信息了， 我们只需要在相关的地方写上

SqlConnection conn =new SqlConnection(connString)即可.