Problem with existing db

[jbergens]

I currently have a problem with Dexie when I try it out with our existing indexedDb (already created in my browser by earlier code). The db seems to be blocked and the code never gets to the resolve parts in the promises parts.

Is this usecase (existing db with some indices) not supported?

It works with a small toy db built from scratch with Dexie with code in the same project.

[dfahlander]

Migration is quite untested, but it reminds me that I should add some unit tests for it to find if we have issues with it. I would like to improve the migration capabilities since it is an important use case.

A good tool to find out how your existing DB can be migrated to Dexie can be found here:
https://github.com/dfahlander/Dexie.js/blob/master/samples/open-existing-db/dump-databases.html

Put that page on your site somewhere and navigate to it. You will get the code needed to define your DB with Dexie.

One specific thing with Dexie is that your index names must be identical to your keypaths. If you have compound indexes, their names must have the following name format: "[" + keyPath1 + "+" + keyPath2 + ... + "]".

Do you have an URL where it is possible to access your application and try debug why the migration is not working? I could give it a try and at the same time learn how to improve the migration capabilities of Dexie.

[jbergens]

Sorry, I don't have the application publically availible right now. I might be able to put together a test environment but you would need to login. Can I send some info by mail to you? Do you have gmail address or similar where I can reach you? I have firstname (johan) dot lastname (bergens) at gmail.
I am working on a smaller demo app which I could probably make availible but I have to recrete all old database creation code which is currently inside a much larger project.

[dfahlander]

Thanks for the access to your site. I was able to test a dexie migration on your data by simulating your URL locally using a local node.js server and some manipulation with my hosts file to pretend being your server. Then I put This file on the node.js server and could dump the data.

I could see that your index names are not same as their corresponding keyPaths, which is the source of the problem. Since I would like to make it easy to migrate to Dexie, I will try improving the library so that it adjusts to the existing index names rather than requiring them to be identical to the keypaths.

I could get the exception though by catching the final promise:

        var db = new Dexie('reqsSbaData');
        db.version(0.2).stores({
            _lookupFields: 'Id',
            _offlineInfo: 'Id',
            protocolEntities: 'ID',
            protocolParts: 'ID,Protokoll',
            protocolPoints: 'ID,Protokolldel',
            remarkTexts: 'ID,keyValue,remarkType,valueField',
            remarks: 'ID,Föräldraentitet,Protokoll,Protokollpunkt',
            serverTypeInfo: 'ID'
        });

        db.open().then(function() {
            console.log("Successfully opened the db"); // This was printed out
            return db.protocolPoints.orderBy("Protokolldel").each(function(item) {
                console.log("protocolPoint: " + JSON.stringify(item, null, 4));
            });
        }).catch(function(err) {
            console.error(err); // I ended up here with a DOMException for not finding the index.
        });

I'll keep this issue be open and write some unit tests that reproduces the problem to begin with.

I also detected an issue with db.on('error') that it did not log the error there, only if i catched the error explicitely. Will be filed as a separate issue.

[jbergens]

Thanks for the help!

I will fix my indices tomorrow and use catch after open too view any errors.
Den 20 nov 2014 21:47 skrev "David Fahlander" notifications@github.com:

Thanks for the access to your site. I was able to test a dexie migration
on your data by simulating your URL locally using a local node.js server
and some manipulation with my hosts file to pretend being your server. Then
I put This file
https://github.com/dfahlander/Dexie.js/blob/master/samples/open-existing-db/dump-databases.html
on the node.js server and could dump the data.

I could see that your index names are not same as their corresponding
keyPaths, which is the source of the problem. Since I would like to make it
easy to migrate to Dexie, I will try improving the library so that it
adjusts to the existing index names rather than requiring them to be
identical to the keypaths.

I could get the exception though by catching the final promise:

    var db = new Dexie('reqsSbaData');
    db.version(0.2).stores({
        _lookupFields: 'Id',
        _offlineInfo: 'Id',
        protocolEntities: 'ID',
        protocolParts: 'ID,Protokoll',
        protocolPoints: 'ID,Protokolldel',
        remarkTexts: 'ID,keyValue,remarkType,valueField',
        remarks: 'ID,Föräldraentitet,Protokoll,Protokollpunkt',
        serverTypeInfo: 'ID'
    });

    db.open().then(function() {
        console.log("Successfully opened the db"); // This was printed out
        return db.protocolPoints.orderBy("Protokolldel").each(function(item) {
            console.log("protocolPoint: " + JSON.stringify(item, null, 4));
        });
    }).catch(function(err) {
        console.error(err); // I ended up here with a DOMException for not finding the index.
    });

I'll keep this issue be open and write some unit tests that reproduces the
problem to begin with.

I also detected an issue with db.on('error') that it did not log the error
there, only if i catched the error explicitely. Will be filed as a separate
issue.

—
Reply to this email directly or view it on GitHub
#30 (comment).

[dfahlander]

Issue fixed in src/Dexie.js. The fix will be part of the next version of Dexie. Until then, use src/Dexie.js.

With the fix, it is now easy to migrate to Dexie since it will no longer require any special format of the index names - it will adapt to the names that your existing db use.