How to write combined query from azure table storage?

Question

I am trying to query from a table so that the name and partition key (combined) unique. I am doing this right now:

public Spec(string name)
{
    Query = new TableQuery<TableEntity>()
        .Where(TableQuery.GenerateFilterCondition(nameof(table.Name), QueryComparisons.Equal, name));
}

but I also need to check partition key exists withing this name. So need to query the table along with the partition key and the name. Can anybody help with this? How to query these as combined query.

Table-queries are only concerned with the contents of entities' properties (columns) within a table. A table's name is completely irrelevant. — Dai, Nov 25 '21 at 16:12
This doesn't look like real code to me - you should not have a table-type named `Table`. And what is `table.Name`? Where is it coming from? (It isn't a parameter of your method). And `public Spec(string name)` looks like a constructor - but you should not be performing IO or much heavy-lifting in a constructor (in fact, you _cannot_ do async IO in a ctor anyway). — Dai, Nov 25 '21 at 16:13
Spec is the method I use to pass the name on it. and yes, Table is the entity class. I use Table here just for showcasing. — saon, Nov 25 '21 at 16:19
`public Spec(string name)` is not a method, that's a constructor. It's missing its return-type. And you haven't answered my question where I ask where `table.Name` is coming from... — Dai, Nov 25 '21 at 16:22

score 1 · Accepted Answer · answered Nov 25 '21 at 18:53

1

Please try something like below:

public Spec(string name)
{
    var filterCondition1 = TableQuery.GenerateFilterCondition("PartitionKey", QueryComparisons.Equal, "PartitionKeyValue");
    var filterCondition2 = TableQuery.GenerateFilterCondition(nameof(table.Name), QueryComparisons.Equal, name);
    Query = new TableQuery<TableEntity>()
        .Where(TableQuery.CombineFilters(filterCondition1, "AND", filterCondition2));
}

answered Nov 25 '21 at 18:53

Gaurav Mantri

128,066
12
206
241

Hey, thank for the suggestions. Do you know if we can check from this Query result if either one of is unique. – saon Nov 26 '21 at 13:05
What do you mean by that? Can you please explain? – Gaurav Mantri Nov 26 '21 at 13:25
Okay, why I am doing this is that: I am trying to validate for the unique name. So, there are multiple names are stored under the same Partition Key. For example: PartitionKey:1, RowKey:1, Name: 'First Name' PartitionKey:1, RowKey: 2, Name:'First Name' – saon Nov 26 '21 at 14:34
If I understand correctly, you want to find out if `Name = 'First Name'` is unique in a partition. Correct? – Gaurav Mantri Nov 26 '21 at 14:36
Yes, This is what I am trying to find. – saon Nov 26 '21 at 14:43
It's actually simple. You simply execute the query and count the number of entities returned :). – Gaurav Mantri Nov 26 '21 at 14:47
Could you give me an example with this? This is for the first time I am doing something with this – saon Nov 26 '21 at 14:49
What's the SDK you're using? – Gaurav Mantri Nov 26 '21 at 14:56
I think it is .net core 3.1 – saon Nov 26 '21 at 20:10

How to write combined query from azure table storage?

1 Answers1