Failed to put my struct to datastore (golang)

Question

here is my struct:

type AreaPrerequisite struct {
    SideQuestId   int // 
    SideQuestProg int // progress
}

type AreaInfo struct {
    Id                int              `datastore:""`
    Name              string           `datastore:",noindex"`
    ActionPoint       int              `datastore:",noindex"`
    Prerequisite      AreaPrerequisite `datastore:",noindex"`

    // ignored:
    DsMonsters        []byte           `datastore:"-"`
    DsStages          []byte           `datastore:"-"`
    Monsters          AreaMonsters     `datastore:"-"`
    Stages            []*StageEntry    `datastore:"-"`
}

and my put() call:

key := datastore.NewKey(c, "Area", "", int64(pArea.Id), nil)
_, err := datastore.Put(c, key, *pArea)
if err != nil {
    return err
}

It gives me the following error when try to put to DS:

datastore: invalid entity type

I checked the doc: https://developers.google.com/appengine/docs/go/datastore/reference

datastore:"-" should mark some non-supported fields ignored by datastore. Don't know why it is failing.

Have you put some data with the same "Area" kind before ? If you have updated your struct after putting some data, the two representations might conflict and produce an error. — val
– val, Commented Aug 16, 2013 at 17:26

Nick · Accepted Answer · 2014-07-16 01:48:17Z

16

I found that I accidentally added * to pArea as arg to put() so it is passing a value instead of pointer, causing invalid entity type error.

edited Jul 16, 2014 at 1:48

user84118

answered Aug 17, 2013 at 4:30

Nick

7837 silver badges24 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Ali Over a year ago

Sir, you saved me too.

Tim Swena Over a year ago

I encountered the same problem, but using PropertyList. Apparently if you pass in a PropertyList it also has to be a pointer not a value. stackoverflow.com/q/30792119/101923

Ido Ran · Accepted Answer · 2015-10-05 07:16:54Z

4

I've also run into that same problem, in my case I didn't put & before the entity to be putted.

key := datastore.NewKey(c, "Area", "", int64(pArea.Id), nil)
_, err := datastore.Put(c, key, &pArea)
if err != nil {
    return err
}

Notice the & before &pArea

answered Oct 5, 2015 at 7:16

Ido Ran

11.5k22 gold badges96 silver badges158 bronze badges

1 Comment

Joey Roosing Over a year ago

This was quite helpful. I actually added & to the object creation, then it can be omitted in the put call. E.G. myObj := &MyObj{} vs myObj := MyObj{}

Collectives™ on Stack Overflow

Failed to put my struct to datastore (golang)

2 Answers 2

2 Comments

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related