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I am using YDN DB for IndexedDB and I want to delete a record from the object store using its id. Here is my schema:

var personsSchema = {
name: "persons",
keyPath: "id",
autoIncrement: true,
indexes: [{
    name: "id",
    unique: true
}, {
    name: "firstname",
    unique: false,
    multiEntry: false
}, {
    name: "lastname",
    unique: false,
    multiEntry: false
}]
};

schema = {
    stores: [personsSchema]
};

var db = new ydn.db.Storage("xdb", schema);

Now, I have function that will delete the record:

    function deleteEntry(id){
        var id = parseInt(id);
        var objectStore = "persons";
        var iterator = new ydn.db.ValueCursors(objectStore, "id", ydn.db.KeyRange.only(id));
        var mode = "readwrite";
        request = db.open(iterator, 1).then(function(cursor){
            cursor.clear();
        }, mode);
    }

This function gives me this error:

Uncaught ydn.error.ArgumentException: Second argument must be cursor range iterator.

Thank you for responses.

4

1 回答 1

2

It should be:

function deleteEntry(id){
    var id = parseInt(id);
    var objectStore = "persons";
    var iterator = new ydn.db.IndexValueCursors(objectStore, "id", ydn.db.KeyRange.only(id));
    var mode = "readwrite";
    request = db.open(function(cursor){
        cursor.clear();
    }, iterator, mode).then(function() {
        console.log('cleared')
    });
}

But since id is primary key, you don't need to be indexed, it should simply be:

function deleteEntry(id){
    var id = parseInt(id, 10);
    var keys = db.remove("persons", id);
}

If id is not primary key, this following code run a bit more efficient, since it does not retrieve record values, unnecessarily.

function deleteEntry(id){
    var id = parseInt(id);
    var objectStore = "persons";
    db.keys(objectStore, "id", ydn.db.KeyRange.only(id)).done(function(keys) { 
      db.remove(objectStore, keys);
    };
}

I have corrected the api doc example.

于 2013-09-10T05:08:14.397 回答