Saving Projections when using InMemDB

EventStoreDB
1

So I have some projections that I’d like to stay persistent between runs using --InMemDB during development. Rebuilding the projections’ results is fine but having to recreate or copy/paste the projection code is getting tedious. Am I missing something basic in the config to allow for this?

Thanks!

2

No you aren’t missing anything - projection definitions are simply events in the database so are also subject to in-memory storage.

Your best bet is to use a wrapper script which recreates the projections on startup.

James

3

Is there any documentation on this. Have been using Node.js for this project (built on top of ges-client) and there is no support for projections built in. I was doing a straight http requests for the projection results, are there related HTTP verbs to do CRUD related operations on projections?

4

There is no documentation on this yet.
The API is described in this controller. https://github.com/EventStore/EventStore/blob/release-v3.4.0/src/EventStore.Projections.Core/Services/Http/ProjectionsController.cs#L54-L94

For example, if you want to create a continuous projection here is the http request to do so.


curl -i -d @projection.json -H "content-type:application/json" "http://localhost:2113/projections/continuous?name=sample_projection&emit=no&checkpoints=yes&enabled=yes" -u admin:changeit

and the projection.json will contain the body of the projection you want to create

fromStream('$stats-127.0.0.1:2113')

.when({

$init:function(){

return {

count:0

}

},

$any:function(s,e){

s.count += 1;

return s;

}

});
5

Sweet! Thanks for this, should be enough to get me started!

6

Just an update if anyone stumbles upon this later.

request
    .post(`[http://localhost:2113/projections/continuous`](http://localhost:2113/projections/continuous%60))
    .query({
        name: path.basename(file,`.js`),
        emit: `no`,
        checkpoints: `yes`,
        enabled: `yes`
    })
    .auth('admin', 'changeit')
    .set('Accept', 'application/json')
    .send(data)
    .end(function (error, response) {
        if(error) {
            console.error(error);
        }
        else{
            const {body} = response;
            const {name} = body;
            console.log(name);
        }
    });

Using superagent here is what a working request looks like in node. Note the data is the javascript file (not json) being uploaded. Thanks Pieter for the help getting started!