无法打开与SQL Server 2012的连接

Question

Hy,

I am using SQL Server 2012 under MS Visual Studio 2012.

Below is my connection string from app.config

<add key="Platform" value="Data Source=Bigfoot2;Initial Catalog=Platform;Integrated Security=True"/>

and my connection class

static SqlConnection con;
        public static SqlConnection GetConnection()
        {
            con = new SqlConnection(ConfigurationManager.AppSettings["Platform"].ToString());
            return con;
        }

 internal void AddCustomer (Buyer customer, User user, PlatformType type )
        {
            SqlConnection conn = DALConnection.GetConnection();

            try
            {
                SqlCommand cmd = new SqlCommand("InsertCustomer", conn);
                cmd.CommandType = CommandType.StoredProcedure;

                 ...

                con.Open();
                cmd.ExecuteNonQuery();

My database is stored under my project folder.

The error I get when I try to use my method is:

Could not open a connection to SQL Server 2012

Sincerely,

Answer 1

Your connection object is wrong, you are passing conn in Command while for Connection open you are using con object not conn :

con.Open();

use :

conn.Open();

you code will be like:

try
            {
                SqlCommand cmd = new SqlCommand("InsertCustomer", conn);
                cmd.CommandType = CommandType.StoredProcedure;
                conn.Open();
                cmd.ExecuteNonQuery();
             }

Answer 2

Although your code has some issues, It seems that it should work.
Try testing your connection string using an independent tool for connectivity.
For testing the connection string take a look at this SO thread .

As @hvd has mentioned in one of the comments, your code is confusing as you have con which is equivalent to conn . this makes your code hard to follow. I recommend you refactor it so it will be easier for you (and others) to follow.

Good luck!

Answer 3

尝试这个：

<add key="Platform" value="Data Source=.\Bigfoot2;Initial Catalog=Platform;Integrated Security=True"/>

Answer 4

If your SQL Server is on a different machine than your Visual Studio or app, are the required ports open in the Windows Firewall ?

Try these steps: http://blog.sujay.sarma.in/2013/12/19/SCRIPT-Open-ports-in-Windows-Firewall-for-SQL-Server-connectivity