Custom query in angular-indexedDB - angularjs

Question

I am using bramski/angular-indexedDB in my application. Basic CRUD operations are working fine, but the custom queries are not working as expected.
I am using the code
angular.module('myModuleName', ['indexedDB'])
.config(function ($indexedDBProvider) {
$indexedDBProvider
.connection('myIndexedDB')
.upgradeDatabase(1, function(event, db, tx){
var objStore = db.createObjectStore('people', {keyPath: 'ssn'});
objStore.createIndex('name_idx', 'age', {unique: false});
objStore.createIndex('name_idx, age_idx', ['name', 'age'] , {unique: false});
});
Basic query operations are working like follows
$indexedDB.openStore('people', function(x){
var find = x.query();
find = find.$eq('John');
find = find.$index("name_idx");
x.eachWhere(find).then(function(e){
$scope.list= e;
});
});
which results following query.
select * from people where name='John'
But, in the above scenario how we can execute custom quires like
select * from people where name='John' and age='25';
delete from people where name='John' and age='25';

Answer 1

The library you are using doesn't have complex queries, however you can write a pure-js solution for it, similar to this:
First you need to define your index as:
objStore.createIndex('name_age_idx', ['name', 'age'] , {unique: false});
Then you can have a search query for only those values that match the search result
searchIndexedDB = function (name, age, callback) {
var request = indexedDB.open(dbName);
request.onsuccess = function(e) {
var db = e.target.result;
var trans = db.transaction(objectStoreName, 'readonly');
var store = trans.objectStore(objectStoreName);
var index = store.index('name_age_idx');
var keyRange = IDBKeyRange.only([name, age]);
// open the index for all objects with the same name and age
var openCursorRequest = index.openCursor(keyRange);
openCursorRequest.onsuccess = function(e) {
let result = e.target.result;
// first check if value is found
if(result){
callback(result.value); // your callback will be called per object
// result.delete() - to delete your object
result.continue(); // to continue itterating - calls the next cursor request
}
};
trans.oncomplete = function(e) {
db.close();
};
openCursorRequest.onerror = function(e) {
console.log("Error Getting: ", e);
};
};
request.onerror = myStorage.indexedDB.onerror;
}
If you need a range from and too index, all you need is change the keyrange to:
var keyRange = IDBKeyRange.bound([name,fromAge], [value, toAge]);