lte which is equivalent to lt which is equivalent to gte which is equivalent to >= - (“Greater Than or Equal To”).gt which is equivalent to > - (“Greater Than”).When using the table resource, we’ll use named operators instead of one of these:, >=. #9 Using lt() - The less than method of Key with the DynamoDB Table Resource
In this context, it is probably just easier to think of it as “and this other condition must also be true” rather than “let’s take the bitwise result of the two Key objects”.
Well, when you take the result of &ing two Keys you get a object that is actually passed to the Ke圜onditionExpression and evaluated by DynamoDB. However, one thing that can be somewhat confusing is wondering what the bitwise and operator & is doing in the Ke圜onditionExpression above. Overall, this Key object syntax can be a bit less verbose and save you time by converting data to native Python types for you automatically. One key difference is that with the table resource, we get the results back without attribute values. This creates a compound Ke圜onditionExpression for us that results in getting the same items as when we used begins_with in the DynamoDB client. eq( 'Arturus Ardvarkian') & Key( 'song'). # Use the Table resource to query all songs by artist Arturus Ardvarkian # that start with 'C' Except, instead of using the eq() method (which we could if we wanted to query for a specific item), we use begins_with(). Rather than passing the table resource’s Ke圜onditionExpression a string, we use two of the Key objects we used previously with it. We used begins_with in the Ke圜onditionExpression with the DynamoDB client, but with the table resource we use a slightly different Ke圜onditionExpression. First, let’s look for songs starting with “C”.
Check local dynamodb how to#
Let’s look at how to do the same things we just did with the DynamoDB client.
Now let’s take a look at how we’d do some similar things with the DynamoDB table resource. #8 Querying with Partition and Sort Keys Using the DynamoDB Table Resource If we used “B” instead of “Bz” for :songval1 then we would end up with song titles starting with “B” too. With open( 'data.json', 'r') as datafile: