尝试从控制台应用程序打开 SQL 连接 - conn.open 终止

Question

我的代码到达 conn.Open 并给我 "Exception thrown: 'System.Data.SqlClient.SqlException' in System.Data.dll"

这是代码块：

        _timer.Stop();
        string path = @"C:\testlog.log";
        SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["MYDB_Conn"].ConnectionString);
        string query = "SELECT RawImportEnabled, ImportDayTimeStamp from Settings";
        SqlCommand cmd = new SqlCommand(query, conn);
        conn.Open(); // Dies here
        SqlDataReader rdr = cmd.ExecuteReader();

Answer 1

订单丢失...首先打开连接然后使用sql命令

_timer.Stop();
        string path = @"C:\testlog.log";
        SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["MYDB_Conn"].ConnectionString);
        conn.Open(); // sholud be here

        string query = "SELECT RawImportEnabled, ImportDayTimeStamp from Settings";
        SqlCommand cmd = new SqlCommand(query, conn);
        SqlDataReader rdr = cmd.ExecuteReader();

此外你的代码也没有格式化..像这样格式化

 string path = @"C:\testlog.log";
            String connectionString = ConfigurationManager.ConnectionStrings["MYDB_Conn"].ConnectionString;
            using (SqlConnection conn = new SqlConnection(connectionString))
            {
                conn.Open(); // sholud be here

                string query = "SELECT RawImportEnabled, ImportDayTimeStamp from Settings";
                SqlCommand cmd = new SqlCommand(query, conn);
                SqlDataReader reader = cmd.ExecuteReader();
                while (reader.Read())
                { 
                    String RawImportEnabled = Convert.ToString(reader["RawImportEnabled"]);
                    //Do some thing
                }
            }

这有一些好处，比如通过放置断点调试连接字符串，处理连接而不用担心 using 语句等

Answer 2

            _timer.Stop();
        string path = @"C:\testlog.log";
        SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["MYDB_Conn"].ConnectionString);
        string query = "SELECT RawImportEnabled, ImportDayTimeStamp from Settings";
        conn.Open(); // Dies here again.
        SqlCommand cmd = new SqlCommand(query, conn);

        SqlDataReader rdr = cmd.ExecuteReader();
        if (rdr.HasRows)

尝试从控制台应用程序打开 SQL 连接 - conn.open 终止

Attempting to open SQL Connection from console application - conn.open dies

c#

database-connection

console-application