datastore: can not runQuery in a transaction

[jasonswearingen]

hello is running a query in a transaction supposed to be supported? I get errors when doing so (invalid response), while running a query outside of transactions works fine, and reading+writing inside a transaction also works.

I'm trying to do a query with a filter "email ="

sorry I can't provide you code, I do my datastore operations via a self-rolled orm.

[stephenplusplus]

It should work, as far as I know. What version of gcloud are you running? I'll try to reproduce.

[jasonswearingen]

thanks Stephen, i'm using 0.27, since it's supposed to work, i'll do a repro and post it here in a few min.

[jasonswearingen]

here is my repro code:

            console.log("################## running datastore transaction query test");
            let key = dataset.key(["test", 123]);

            dataset.upsert({
                key: key,
                data: { email: "test@example.com" }
            }, (err, upsertResponse) => {

                if (err != null) {
                    console.log("!!!!!!!!!!!!!!!!!!!!!!!! dataset.upsert err", err.message);
                    throw err;
                }
                console.log("################## upsert complete");

                dataset.runInTransaction((transaction, done) => {

                    let query = dataset.createQuery("test");
                    query.filter("email =", "test@example.com");

                    transaction.runQuery(query, (err, entities) => {

                        if (err != null) {
                            console.log("!!!!!!!!!!!!!!!!!!!!!!!! transaction.runQuery err",err.message);
                            throw err;
                        }

                        console.log("################## transaction.runQuery complete");
                        for (let i = 0; i < entities.length; i++) {
                            let current = entities[i];
                            console.log("################## entity " + i, current.key.path.join(), JSON.stringify(current.data));
                        }

                    });

                }, (err, transactionResponse) => {
                    if (err != null) {
                        console.log("!!!!!!!!!!!!!!!!!!!!!!!! transaction.runInTransaction err", err.message);
                        throw err;
                    }
                    console.log("################## transaction.runInTransaction complete");

                });


            });

and here is my console output:

################## running datastore transaction query test
################## upsert complete
!!!!!!!!!!!!!!!!!!!!!!!! transaction.runQuery err Bad Request
ApiError: Bad Request
    at new util.ApiError (C:\repos\stage3\nlib\node_modules\gcloud\lib\common\util.js:92:10)
    at Object.parseHttpRespMessage (C:\repos\stage3\nlib\node_modules\gcloud\lib\common\util.js:134:33)
    at Request._callback (C:\repos\stage3\nlib\node_modules\gcloud\lib\datastore\request.js:813:31)
    at Request.self.callback (C:\repos\stage3\nlib\node_modules\request\request.js:199:22)
    at emitTwo (events.js:87:13)
    at Request.emit (events.js:172:7)
    at Request.<anonymous> (C:\repos\stage3\nlib\node_modules\request\request.js:1036:10)
    at emitOne (events.js:82:20)
    at Request.emit (events.js:169:7)
    at IncomingMessage.<anonymous> (C:\repos\stage3\nlib\node_modules\request\request.js:963:12)
    at emitNone (events.js:72:20)
    at IncomingMessage.emit (events.js:166:7)
    at endReadableNT (_stream_readable.js:905:12)
    at nextTickCallbackWith2Args (node.js:474:9)
    at process._tickCallback (node.js:388:17)
[ERROR] 07:59:27 ApiError

[stephenplusplus]

I ran this test with v0.28, which reports more helpful errors. Try updating just to make the experience a little better-- it will require one change:

-query.filter("email =", "test@example.com");
+query.filter("email", "test@example.com");

Anyway, because I upgraded and received the better error reporting, what I got was:

ApiError: Bad Request - queries inside transactions must have ancestors

There's a description of what that means here: https://cloud.google.com/appengine/docs/python/datastore/queries#queries_inside_transactions_must_include_ancestor_filters

See if with this information you can produce the desired results. If not, we can call for some more help :)

[jasonswearingen]

ok thanks, i don't know much about ancestors (have deliberately avoided them), so pretty sure none of my data uses them, so it looks like I can't query in transactions in my use-case. It seems ok though (and probably better): I worked around this by running my query first, and then run the transaction.

[stephenplusplus]

Cool! Let me know if there are any other questions or issues with this approach.