Querying Azure Table Storage with an expression-CodePudding

I'm looking to query table storage by passing an expression into my repository instead of a TableQuery, i'm aiming for this:

public async Task<IEnumerable<FiltersEntity>> Get(Expression<Func<FiltersEntity, bool>> query)
{  
    var table = _tableStorageConnector.CreateTableIfNotExists(_tableName);


    return await table.CreateQuery<FiltersEntity>().Where(query).ToList();
}

Ideal usage:

    var data = await _filterRepository.Get(x => x.PartitionKey.Equals("examplepartitionkey"));

I can't see any methods on CreateQuery or CreateQuery which accept an expression, only text.

I've also looked to see if I can convert the expression to filter text such as PartitionKey eq examplepartitionkey, but no luck.

Can someone please help me query azure table storage via expression?

The SDK i'm using is Microsoft.Azure.Cosmos.Table v1.0.7.0;

CodePudding user response：

Assuming using the Cosmos table driver against Azure Table Storage, you should be able to something along the lines of

public async Task<IEnumerable<MyTable>> MyQuery(Expression<Func<MyTable, bool>> predicate)
{
    var tableClient = new CloudTableClient(
        new Uri("..."),
        new StorageCredentials(".."));

    var table = tableClient.GetTableReference("MyTable");

    var tableQuery = table.CreateQuery<MyTable>()
        .Where(predicate)
        .AsTableQuery(); // << convert back from IQueryable to TableQuery

    var onePage = await table.ExecuteQuerySegmentedAsync(tableQuery, null);
    return onePage.Results;
}

Where MyTable implements ITableEntity and extends custom columns.

Note if the query is likely to return more than one page of data, then you'll need to replace the null with a TableContinuationToken and collect the pages in a loop.

I do agree that the number of, and guidance toward, client libraries for Azure Table storage is becoming quite frustrating.