CODEWITHSUNDEEP
linqazurelambdaexpressionpredicatebuilder
Jason Coyne
Jason Coyne

Reputation: 6636

Is there a way to use PredicateBuilder with Azure Table Storage?

Just what it says on the tin, I have a design problem where normally PredicateBuilder would be the obvious answer, but when executing, I get errors such as : 

The expression 
((([10007].PartitionKey == "df2907ad-2094-4b7a-9796-d077f14b25bc") 
And True) 
And Invoke(f => (True AndAlso Invoke(job => (job.MigrationExecutionId == "5fa0bd4c-4745-4452-8e52-a0329c00dafb"), f)), [10007])) 
is not supported.

Any way to use Predicate builder, or some other form of expression tree syntax to build up a query and run it against Azure Table?

Upvotes: 3

Views: 422

Answers (2)

Sean Kearon
Sean Kearon

Reputation: 11427

Yes, you can use PredicateBuilder with Azure Table Storage. Let's say you want to build a query of the format (pseudo code):

where partitionkey = "X" and (email = "Y" or email = "Z")

This can be done as follows

    public string[] GetByEmail(string companyId, string[] emails)
    {
        var inner = PredicateBuilder.New<IssuerTableEntity>(false);
        foreach (var email in emails.Select(x => x.ToLowerInvariant()).Distinct())
        {
            var temp = email;
            inner = inner.Or(x => x.EmailLowercase == temp);
        }

        var outer = PredicateBuilder.New<MyTableEntity>(false);
        outer = outer.And(x => x.PartitionKey == companyId);
        outer = outer.And(inner);

        CloudTable table = GetTable(MyTableName);  
        return table.CreateQuery<MyTableEntity>()
            .Where(outer)
            .Select(x => x.RowKey)
            .ToArray();
    }

Note the use of Distinct() - this was because I got errors when supplying duplicates.

Upvotes: 0

Igorek
Igorek

Reputation: 15860

Short answer: no. ATS offers only limited linq support.

Upvotes: 1

Related Questions