How Mapper handles updates/delete to/from set/list/map

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Yarden Bar

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May 24, 2020, 1:30:54 AM5/24/20
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Hello,

I have a table with complex types (not UDTs), such as:
field1 text,
field2 text,
field3 set<text>,
PRIMARY KEY (field1)


Reading the documentation, I could not deduce how the Mapper will handle updates/upserts/deletes to/from set/list/map.

My guess would be that if its not supported, then I'd need to use "mapWithQuery" to bypass the query generation.

Any direction will help,
J

Jorge Bay Gondra

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May 25, 2020, 4:12:02 AM5/25/20
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Hi,
The Mapper uses the default type mapping of the core driver, you can look at the documentation for CQL types to ECMAScript types here: https://docs.datastax.com/en/developer/nodejs-driver/4.5/features/datatypes/

For example, given the schema you send, it would be something like:

sampleMapper.insert({ field1: 'value a', field2: 'value b', field3: [ 'set value 1', 'set value 2' ] })

Thanks,
Jorge

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Yarden Bar

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Jun 17, 2020, 3:28:11 PM6/17/20
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Hi Jorge,
Thank you for the example. how would that work for updates?
Wholesale approach where i have to read the collection first, modify it and update the new value?
or
Updating a collection has some syntax similar to CQL "mySet = mySet - itemsToRemove"?

Thank you,
Yarden

On Monday, May 25, 2020 at 1:12:02 AM UTC-7, Jorge Bay Gondra wrote:
Hi,
The Mapper uses the default type mapping of the core driver, you can look at the documentation for CQL types to ECMAScript types here: https://docs.datastax.com/en/developer/nodejs-driver/4.5/features/datatypes/

For example, given the schema you send, it would be something like:

sampleMapper.insert({ field1: 'value a', field2: 'value b', field3: [ 'set value 1', 'set value 2' ] })

Thanks,
Jorge

On Sun, May 24, 2020 at 7:30 AM Yarden Bar <ayash...@gmail.com> wrote:
Hello,

I have a table with complex types (not UDTs), such as:
field1 text,
field2 text,
field3 set<text>,
PRIMARY KEY (field1)


Reading the documentation, I could not deduce how the Mapper will handle updates/upserts/deletes to/from set/list/map.

My guess would be that if its not supported, then I'd need to use "mapWithQuery" to bypass the query generation.

Any direction will help,
J

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Jorge Bay Gondra

Jorge Bay Gondra

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Jun 18, 2020, 5:05:24 AM6/18/20
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Hi,
The update statements would work in the same way for a full value replacement.

If you want to add values to the set (if not already there), you can use q.append():

// import q
const q = cassandra.mapping.q;

// Use q.append() in a update query for the column "tags"
videoMapper.update({ id, tags: q.append(['coding', 'nodejs']) })

Here's a test in the repo that shows the logic: https://github.com/datastax/nodejs-driver/blob/265118f7f0aa9ba6800ebebd400b6a6bdf841285/test/integration/short/mapping/model-mapper-tests.js#L543-L554

Thanks,
Jorge


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Jorge Bay Gondra

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Yarden Bar

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Jun 19, 2020, 12:34:04 PM6/19/20
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Great! I'll look into that


On Thursday, June 18, 2020 at 2:05:24 AM UTC-7, Jorge Bay Gondra wrote:
Hi,
The update statements would work in the same way for a full value replacement.

If you want to add values to the set (if not already there), you can use q.append():

// import q
const q = cassandra.mapping.q;

// Use q.append() in a update query for the column "tags"
videoMapper.update({ id, tags: q.append(['coding', 'nodejs']) })


Thanks,
Jorge

To unsubscribe from this group and stop receiving emails from it, send an email to nodejs-driver-user+unsub...@lists.datastax.com.


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Jorge Bay Gondra

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