以编程方式测试SQL Server连接的最佳方式是什么？

Question

我需要开发一个例程，它将每5分钟触发一次，以检查SQL Server (10到12)的列表是否已启动并正在运行。

有没有一种方法可以简单地从C# one "ping“SQL Server，并且只需最少的代码和sql操作需求？

Answer 1

执行SELECT 1并检查ExecuteScalar是否返回1。

Answer 2

当服务器停止或暂停连接时，我遇到了EF的问题，我提出了同样的问题。因此，为了完整地回答上面的问题，下面是代码。

/// <summary>
/// Test that the server is connected
/// </summary>
/// <param name="connectionString">The connection string</param>
/// <returns>true if the connection is opened</returns>
private static bool IsServerConnected(string connectionString)
{
    using (SqlConnection connection = new SqlConnection(connectionString))
    {
        try
        {
            connection.Open();
            return true;
        }
        catch (SqlException)
        {
            return false;
        }
    }
}

Answer 3

请参阅GitHub上的以下项目：https://github.com/ghuntley/csharp-mssql-connectivity-tester

try
{
    Console.WriteLine("Connecting to: {0}", AppConfig.ConnectionString);
    using (var connection = new SqlConnection(AppConfig.ConnectionString))
    {
        var query = "select 1";
        Console.WriteLine("Executing: {0}", query);

        var command = new SqlCommand(query, connection);

        connection.Open();
        Console.WriteLine("SQL Connection successful.");

        command.ExecuteScalar();
        Console.WriteLine("SQL Query execution successful.");
    }
}
catch (Exception ex)
{
    Console.WriteLine("Failure: {0}", ex.Message);
}