当使用ng-show/ng-hide隐藏地图时,一旦可见,它就无法正确显示.标准地图也有同样的问题,因为我们可以访问地图对象,所以我们可以向它发送调整大小.
这是一个以隐藏地图开头的示例.该按钮可切换地图的可见性.
<!doctype html>
<html>
<head>
<style>
.angular-google-map-container {
width: 100%;
height: 100px;
}
.mymap {
width: 100%;
height: 100px;
}
</style>
</head>
<body ng-app="app" ng-controller="myCtrl">
<button ng-click="visible = !visible">ToogleMap</button>
<div ng-show="visible">
<google-map center="map.center" zoom="map.zoom"></google-map>
<div class="mymap"></div>
</div>
<script src='https://ajax.googleapis.com/ajax/libs/angularjs/1.3.0-beta.8/angular.min.js'></script>
<script src='http://maps.googleapis.com/maps/api/js?sensor=false'></script>
<script src='http://underscorejs.org/underscore-min.js'></script>
<script src='https://rawgithub.com/nlaplante/angular-google-maps/master/dist/angular-google-maps.min.js'></script>
<script>
var app = angular.module("app", ["google-maps"]);
app.controller("myCtrl", function($scope, $timeout) {
$scope.map = {
center: {
latitude: 45.4,
longitude: -71.9
},
zoom: 11
};
$scope.visible = false;
});
</script>
</body>
</html>
使用js中的google-maps,我会向地图对象发送一个调整大小,但我无法在angular-google-maps中访问它.
我想删除sqlalchemy中具有多态关系的表中的一些元素。这是模型：
class Employee(Base):
__tablename__ = 'employee'
id = Column(Integer, primary_key=True)
name = Column(String(50))
type = Column(String(50))
__mapper_args__ = {
'polymorphic_identity':'employee',
'polymorphic_on':type
}
class Engineer(Employee):
__tablename__ = 'engineer'
id = Column(Integer, ForeignKey('employee.id'), primary_key=True)
engineer_name = Column(String(30))
__mapper_args__ = {
'polymorphic_identity':'engineer',
}
这是我删除它的方法：
e = Engineer();
e.name = "John";
e.engineer_name = "Doe";
DBSession.add(e);
q = session.query(Engineer).filter(Employee.name == "John")
q.delete(False)
我收到以下错误，这是一个错误还是我的操作方式错误？
sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) no such
column: employee.name [SQL: u'DELETE FROM engineer WHERE employee.name
= ?'] [parameters: ('John',)]
我期望 sqlalchemy 删除工程师和员工表中的条目。