删除约束时执行超时

Question

我正在使用powershell和bcp将数千个文件加载到表中。对于每个数据文件，我都会为要填充的列创建默认值。然后，我删除该默认值，并为下一个文件添加一个新值，以此类推。

代码在这里：

let isDragging = false;
let $target = null;
let mouseY = 0;
let pMouseY = 0;
const handleHeight = 12;

const $layout = $('.layout'),
      $panels = $('.panel'),
      $handles = $('.v-handle');

$panels.on('resize-panel', function() {
  let canResize = true;
  $this = $(this);
  $prev = $(this).prev();
  $next = $(this).next();

  if(mouseY - pMouseY > 0) {
    // we're draggin down
    if($this.height() - (mouseY - pMouseY) < handleHeight) {
      console.log('check below');
      canResize = ($next.length != 0 && $next.trigger('resize-panel'));
    }
  } else {
    // we're dragging up      
    if($prev.height() + (mouseY - pMouseY) < handleHeight) {
      console.log('check above');
      canResize = ($prev.trigger('resize-panel'));
    }
  }

  if(canResize) {
    $this.css('height', $this.height() - (mouseY - pMouseY));
    $prev.css('height', $prev.height() + (mouseY - pMouseY));
  }
  return canResize;

});


$handles.on('mousedown', function(e) {
  isDragging = true;
  $target = $(this);
  mouseY = pMouseY = e.clientY;
  console.log('mousedown');
});
$layout.on('mousemove', function(e) {
  if(isDragging) {
    mouseY = e.clientY;

    $target.parent().trigger('resize-panel');

    pMouseY = e.clientY;

  }
})
.on('mouseup', function() {
  isDragging = false;
});

我已经从bcp命令中删除了标识信息。该代码在循环中运行数千次，每个数据文件一次。在某个时候，我收到以下超时错误。

$query = "alter table $tableName add constraint DF_temp_jobID_$tableName default $dir_id for jobID"
$sqlCmd2 = $connection.CreateCommand()
$sqlCmd2.Connection = $connection
$sqlCmd2.CommandText = $query
$sqlCmd2.ExecuteReader()
bcp "$tableName" in "$dir_id${string}.csv" -f "formatFile_file.fmt" -U 
$query = "alter table $tableName drop constraint DF_temp_jobID_$tableName"
$sqlCmd3 = $connection.CreateCommand()
$sqlCmd3.Connection = $connection
$sqlCmd3.CommandText = $query
$sqlCmd3.ExecuteReader()

此错误发生得相当快。默认超时为600秒左右。我没有等那么久。我不明白为什么您在删除或添加约束时会超时。感觉应该是一个恒定时间的操作，或者接近它。