ProviderHostedCustomUIActionsWeb.SharePointContext.GetDatabaseConnectionString C# (CSharp) Method

        public string GetDatabaseConnectionString()
        {
            string dbConnectionString = null;

            using (ClientContext clientContext = CreateAppOnlyClientContextForSPHost())
            {
                if (clientContext != null)
                {
                    var result = AppInstance.RetrieveAppDatabaseConnectionString(clientContext);

                    clientContext.ExecuteQuery();

                    dbConnectionString = result.Value;
                }
            }

            if (dbConnectionString == null)
            {
                const string LocalDBInstanceForDebuggingKey = "LocalDBInstanceForDebugging";

                var dbConnectionStringSettings = WebConfigurationManager.ConnectionStrings[LocalDBInstanceForDebuggingKey];

                dbConnectionString = dbConnectionStringSettings != null ? dbConnectionStringSettings.ConnectionString : null;
            }

            return dbConnectionString;
        }