AzureStorage 表查询：构建包含筛选器

Question

I'm aware that Azure Storage doesn't have a contains like filter in their current API. However, I also know that you can build a contains like filter for strings using code like the following:

            TableQuery<TableEntity> Query = new TableQuery<TableEntity>()
            .Where(
            TableQuery.CombineFilters(
                TableQuery.GenerateFilterCondition("PartitionKey", QueryComparisons.GreaterThanOrEqual, substring),
                TableOperators.And,
                TableQuery.GenerateFilterCondition("PartitionKey", QueryComparisons.LessThan, substring + someValue)
                ));

My Question is what should I use as someValue to make this equivalent to a contains?

I can't seem to find a chart online that indicates what char is the first char for all chars lexigraphically for c#. Is there any reason not to do this, and do the search on the client side? My partitionKey is well defined subgroups.

Thanks in advance!

Answer 1

It actually uses the ascii order to compare in the filter.

For example, if the substring is good , then in the second filter:

TableQuery.GenerateFilterCondition("PartitionKey", QueryComparisons.LessThan, "good" + someValue) ,

you should change it to

TableQuery.GenerateFilterCondition("PartitionKey", QueryComparisons.LessThan, "gooe")

There is no need to add someValue . Just replace the last char for your substring, to the next ascii char.