javascript - Error with $cordovaSQLite plugin on ionic -

i want query's on db ... problem when run app, screen blank, don't why. read in ionic.platform.ready() , run perfect when want use in controller wrong when blank screen...

that's code in .ready() function:

    var primera=[];     var contador=0;     var citas = window.sqliteplugin.opendatabase({name: "citas.db", location: 'default'});     var query= "select * usuario codigo=?";     $cordovasqlite.execute(citas, query, [0]).then(function(data){       contador=data.rows.length;       (var = 0; < data.rows.length; i++) {         var datos={           codigo:'',           telefono:'',           password:'',           status:''         };         datos.codigo = data.rows.item(i).codigo;         datos.telefono = data.rows.item(i).telefono;         datos.password= data.rows.item(i).password;         datos.status= data.rows.item(i).status;         primera.push(datos);       }//fin del       //alert("select activo de app");      }, function(err){     alert('error al insertar datos primarios');     });//fin del execute 

that code in controller:

var citas=window.sqliteplugin.opendatabase({name: 'citas.db', location: 'default'}); var query= "select * usuario codigo=?"; $cordovasqlite.execute(citas, query, [0]).then(function(data){   alert("entro en execute");   (var = 0; < data.rows.length; i++) {      var datos={     codigo:'',     telefono:'',     password:'',     status:''     };     datos.codigo = data.rows.item(i).codigo;       datos.telefono = data.rows.item(i).telefono;       datos.password= data.rows.item(i).password;       datos.status= data.rows.item(i).status;       $scope.sesion.push(datos);   }//fin del   alert('descarga completada');   if($scope.sesion[0].status=='activo'){       $scope.tlf_login=$scope.sesion[0].telefono;       $scope.pass_login=$scope.sesion[0].password;       buscarpersona();     } }, function(err){     alert('error al recuperar datos'); });//fin del execute  

i resolve that, do? well.. procedure convert function , use delay $timeout before execute function, guess problem native function sqlite device should ready use that.. in many word's:

$timeout(function() { $scope.verificar_sesion(); }, 500);