Windows Azure表存储中的批量删除 [英] Batch delete in Windows Azure Table Storage
问题描述
我正在尝试删除WADLogsTable
中2个日期(即2个分区键)之间的所有实体.
到目前为止,我发现的最好的代码就是这个代码(来自
I'm trying to delete all entities between 2 dates (i.e. 2 partition keys) in the WADLogsTable
.
So far, the best code I've found is this one (from http://wintellect.com/blogs/jlane/deleting-entities-in-windows-azure-table-storage):
private static void DeleteAllEntitiesInBatches(CloudTable table, Expression<Func<DynamicTableEntity, bool>> filters)
{
Action<IEnumerable<DynamicTableEntity>> processor = entities =>
{
var batches = new Dictionary<string, TableBatchOperation>();
foreach (var entity in entities)
{
TableBatchOperation batch = null;
if (batches.TryGetValue(entity.PartitionKey, out batch) == false)
{
batches[entity.PartitionKey] = batch = new TableBatchOperation();
}
batch.Add(TableOperation.Delete(entity));
if (batch.Count == 100)
{
table.ExecuteBatch(batch);
batches[entity.PartitionKey] = new TableBatchOperation();
}
}
foreach (var batch in batches.Values)
{
if (batch.Count > 0)
{
table.ExecuteBatch(batch);
}
}
};
ProcessEntities(table, processor, filters);
}
private static void ProcessEntities(CloudTable table, Action<IEnumerable<DynamicTableEntity>> processor, Expression<Func<DynamicTableEntity, bool>> filters)
{
TableQuerySegment<DynamicTableEntity> segment = null;
while (segment == null || segment.ContinuationToken != null)
{
if (filters == null)
{
segment = table.ExecuteQuerySegmented(new TableQuery().Take(100), segment == null ? null : segment.ContinuationToken);
}
else
{
var query = table.CreateQuery<DynamicTableEntity>().Where(filters).Take(100).AsTableQuery();
segment = query.ExecuteSegmented(segment == null ? null : segment.ContinuationToken);
}
processor(segment.Results);
}
}
但是我不知道我应该通过什么作为过滤器"参数. 我想出了一个相当幼稚的尝试:
But I don't know what I should pass as the "filters" parameter. I came up with this rather naive attempt:
Expression<Func<DynamicTableEntity, bool>> filters = e => long.Parse(e.PartitionKey) >= startTicks && long.Parse(e.PartitionKey) <= endTicks;
但这不起作用.在运行时,出现以下错误:
But that doesn't work. At runtime, I get the following error:
表达式((Parse([10007] .PartitionKey)> = 635109048000000000) 并且(Parse([10007] .PartitionKey)< = 635115960000000000))不是 支持.
The expression ((Parse([10007].PartitionKey) >= 635109048000000000) And (Parse([10007].PartitionKey) <= 635115960000000000)) is not supported.
我不知道我的问题是否与Azure表或Expression有关,但是任何帮助将不胜感激.
I don't know if my problem is related to Azure tables or Expression but any help will be appreciated.
编辑:如果需要,我很乐意提供更多信息.
I'd be happy to provide with more info if needed.
推荐答案
我在另一个论坛上得到了答案:
I got an answer on another forum:
var startTicks = string.Format("{0:0000000000000000000}", start);
var endTicks = string.Format("{0:0000000000000000000}", end);
Expression<Func<DynamicTableEntity, bool>> filters = e => e.PartitionKey.CompareTo(startTicks) >= 0 && e.PartitionKey.CompareTo(endTicks) <= 0;
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