所以我正在寻找相当于WHERE IN(val1,val2)我试过这样但是不起作用.
Angular Firebase
this.firebase.database.list('/favorites',{
query: {
orderByChild: 'uID',equalTo: [1,2,3,'some value]
}
});
解决方法
Firebase的查询没有OR或IN运算符.因此,您无法轻松将上述查询映射到Firebase.
一种解决方法是在元素上实现multiFilter：
public items: FirebaseListObservable<any[]> = null;
ngOnInit() {
this.items = this.db.list('/favorites',{
query: {
orderByChild: 'uID'
}
});
this.items.subscribe(items => {
console.info(this.multiFilter(items,{'uID': [1,'some value]}));
});
}
public multiFilter(arr: Object[],filters: Object) {
const filterKeys = Object.keys(filters);
return arr.filter(eachObj => {
return filterKeys.every(eachKey => {
if (!filters[eachKey].length) {
return true; // passing an empty filter means that filter is ignored.
}
return filters[eachKey].includes(eachObj[eachKey]);
});
});
};
