Question

    try
    {
        conn.Open();
        SqlDataReader reader = cmd.ExecuteReader();
        if (reader.HasRows)
        {
            while (reader.Read())
            {
                var a = reader.GetString(1);
                var b = reader.GetString(3);
                var c = reader.GetString(4);
                var d = reader.GetString(5);
                await context.PostAsync($" ### Please find below the fleet policy information \n #### Policy number - " +
                    $"`{a}` \n #### Policy type - `{b}` \n #### Property - `{c}` \n #### Number - `{d}` ");
            }
        }
        else
        {
            await context.PostAsync($"Fleet policy with number **{policyNum}** not found");
        }
    }
    catch (SqlException ex)
    {
        await context.PostAsync("cannot connect to database");

    }
    finally
    {
        conn.Close();
        PromptDialog.Confirm(context, afterOkAsync, "You still want to check fleet policy?", "Didn't get that, Please select either yes or no", promptStyle: PromptStyle.PerLine);

    }

如果数据库连接不成功，我希望代码捕获异常，但它不起作用。请问代码有什么问题？所有其他人都在工作，但我也对捕获无法连接数据库异常感兴趣

Answer 1

如果数据库连接不成功，则可能会出现与SqlException不同的异常。只有在抛出SqlException时才会捕获。

您可以在下面找到SqlConnection.Open的例外列表：

https://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlconnection.open(v=vs.110).aspx

如何捕获无法连接到数据库异常

1 个答案: