我以为我试图做一些非常简单的事情。我只想在屏幕上报告一个正在运行的号码，以便用户知道我正在执行的SQL存储过程正在运行，并且他们没有耐心并开始点击按钮。
问题是我无法弄清楚如何实际调用ExecutNonQueryAsync命令的进度报告器。它停留在我的报告循环中并且从不执行命令但是，如果我把它放在async命令之后，它将被执行并且结果永远不会等于零。
任何想法，评论，想法将不胜感激。非常感谢你！
int i = 0;
lblProcessing.Text = "Transactions " + i.ToString();
int result = 0;
while (result==0)
{
i++;
if (i % 500 == 0)
{
lblProcessing.Text = "Transactions " + i.ToString();
lblProcessing.Refresh();
}
}
// Yes - I know - the code never gets here - that is the problem!
result = await cmd.ExecuteNonQueryAsync();
答案 0 :(得分：5)
最简单的方法是使用第二个连接来监控进度并报告。这里有一个小样本可以帮助您入门：
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Text;
using System.Threading.Tasks;
namespace Microsoft.Samples.SqlServer
{
public class SessionStats
{
public long Reads { get; set; }
public long Writes { get; set; }
public long CpuTime { get; set; }
public long RowCount { get; set; }
public long WaitTime { get; set; }
public string LastWaitType { get; set; }
public string Status { get; set; }
public override string ToString()
{
return $"Reads {Reads}, Writes {Writes}, CPU {CpuTime}, RowCount {RowCount}, WaitTime {WaitTime}, LastWaitType {LastWaitType}, Status {Status}";
}
}
public class SqlCommandWithProgress
{
public static async Task ExecuteNonQuery(string ConnectionString, string Query, Action<SessionStats> OnProgress)
{
using (var rdr = await ExecuteReader(ConnectionString, Query, OnProgress))
{
rdr.Dispose();
}
}
public static async Task<DataTable> ExecuteDataTable(string ConnectionString, string Query, Action<SessionStats> OnProgress)
{
using (var rdr = await ExecuteReader(ConnectionString, Query, OnProgress))
{
var dt = new DataTable();
dt.Load(rdr);
return dt;
}
}
public static async Task<SqlDataReader> ExecuteReader(string ConnectionString, string Query, Action<SessionStats> OnProgress)
{
var mainCon = new SqlConnection(ConnectionString);
using (var monitorCon = new SqlConnection(ConnectionString))
{
mainCon.Open();
monitorCon.Open();
var cmd = new SqlCommand("select @@spid session_id", mainCon);
var spid = Convert.ToInt32(cmd.ExecuteScalar());
cmd = new SqlCommand(Query, mainCon);
var monitorQuery = @"
select s.reads, s.writes, r.cpu_time, s.row_count, r.wait_time, r.last_wait_type, r.status
from sys.dm_exec_requests r
join sys.dm_exec_sessions s
on r.session_id = s.session_id
where r.session_id = @session_id";
var monitorCmd = new SqlCommand(monitorQuery, monitorCon);
monitorCmd.Parameters.Add(new SqlParameter("@session_id", spid));
var queryTask = cmd.ExecuteReaderAsync( CommandBehavior.CloseConnection );
var cols = new { reads = 0, writes = 1, cpu_time =2,row_count = 3, wait_time = 4, last_wait_type = 5, status = 6 };
while (!queryTask.IsCompleted)
{
var firstTask = await Task.WhenAny(queryTask, Task.Delay(1000));
if (firstTask == queryTask)
{
break;
}
using (var rdr = await monitorCmd.ExecuteReaderAsync())
{
await rdr.ReadAsync();
var result = new SessionStats()
{
Reads = Convert.ToInt64(rdr[cols.reads]),
Writes = Convert.ToInt64(rdr[cols.writes]),
RowCount = Convert.ToInt64(rdr[cols.row_count]),
CpuTime = Convert.ToInt64(rdr[cols.cpu_time]),
WaitTime = Convert.ToInt64(rdr[cols.wait_time]),
LastWaitType = Convert.ToString(rdr[cols.last_wait_type]),
Status = Convert.ToString(rdr[cols.status]),
};
OnProgress(result);
}
}
return queryTask.Result;
}
}
}
}
您会称之为：
class Program
{
static void Main(string[] args)
{
Run().Wait();
}
static async Task Run()
{
var constr = "server=localhost;database=tempdb;integrated security=true";
var sql = @"
set nocount on;
select newid() d
into #foo
from sys.objects, sys.objects o2, sys.columns
order by newid();
select count(*) from #foo;
";
using (var rdr = await SqlCommandWithProgress.ExecuteReader(constr, sql, s => Console.WriteLine(s)))
{
if (!rdr.IsClosed)
{
while (rdr.Read())
{
Console.WriteLine("Row read");
}
}
}
Console.WriteLine("Hit any key to exit.");
Console.ReadKey();
}
}
哪个输出：
Reads 0, Writes 0, CPU 1061, RowCount 0, WaitTime 0, LastWaitType SOS_SCHEDULER_YIELD, Status running
Reads 0, Writes 0, CPU 2096, RowCount 0, WaitTime 0, LastWaitType SOS_SCHEDULER_YIELD, Status running
Reads 0, Writes 0, CPU 4553, RowCount 11043136, WaitTime 198, LastWaitType CXPACKET, Status suspended
Row read
Hit any key to exit.
答案 1 :(得分：4)
你无法让ExecuteNonQueryAsync在这里做你想做的事。要执行您要查找的内容，该方法的结果必须是逐行或在SQL调用期间递增的块中，但这不是如何将查询批处理提交到SQL Server的工作方式或实际上您希望如何从头顶上看工作。将SQL语句交给服务器，在完成语句处理后，它返回受语句影响的总行数。
答案 2 :(得分：3)
您是否只是想让用户知道发生了什么事情，而您实际上并不需要显示当前进度？
如果是这样，您只需显示ProgressBar，其Style设置为Marquee。
如果您希望这是一种“自包含”方法，您可以在模态表单上显示进度条，并在表单中包含表单代码。
E.g。
public void ExecuteNonQueryWithProgress(SqlCommand cmd) {
Form f = new Form() {
Text = "Please wait...",
Size = new Size(400, 100),
StartPosition = FormStartPosition.CenterScreen,
FormBorderStyle = FormBorderStyle.FixedDialog,
MaximizeBox = false,
ControlBox = false
};
f.Controls.Add(new ProgressBar() {
Style = ProgressBarStyle.Marquee,
Dock = DockStyle.Fill
});
f.Shown += async (sender, e) => {
await cmd.ExecuteNonQueryAsync();
f.Close();
};
f.ShowDialog();
}
答案 3 :(得分：3)
这是一个有趣的问题。我过去不得不实施类似的事情。在我们的案例中，优先事项是：
我要做的是使用线程在后台运行该过程，如：
HostingEnvironment.QueueBackgroundWorkItem(ct => FunctionThatCallsSQLandTakesTime(p, q, s));
然后使用一种估计工作时间的方法，我会在时钟上从客户端增加进度条。为此，查询数据中的变量，使其与FunctionThatCallsSQLandTakesTime所需的工作时间成线性关系。
例如;本月活跃用户数驱动FunctionThatCallsSQLandTakesTime占用的时间。每10000个用户需要5分钟。因此，您可以相应地更新进度条。
答案 4 :(得分：1)
我想知道这是否合理：
IAsyncResult result = cmd2.BeginExecuteNonQuery();
int count = 0;
while (!result.IsCompleted)
{
count++;
if (count % 500 == 0)
{
lblProcessing.Text = "Transactions " + i.ToString();
lblProcessing.Refresh();
}
// Wait for 1/10 second, so the counter
// does not consume all available resources
// on the main thread.
System.Threading.Thread.Sleep(100);
}