使用navParams的Angularfire2查询不起作用

Question

I want to get some data using navParams but it is not working but if I provide static value then it's work. I don't know what is wrong. Here is my code that does not work and return empty

console.log(this.navParams.get('id')) // prints 10
const id = this.navParams.get('id');
this.categoryRef = this.db.list('/category', ref => ref.orderByChild('id').equalTo(id));
this.category = this.categoryRef.snapshotChanges().map(changes => {
    return changes.map(c => ({ key: c.payload.key, ...c.payload.val() }));
});

if I give static value then it works like

const id = 10;
this.categoryRef = this.db.list('/category', ref => ref.orderByChild('id').equalTo(id));
this.category = this.categoryRef.snapshotChanges().map(changes => {
    return changes.map(c => ({ key: c.payload.key, ...c.payload.val() }));
});

Answer 1

Can you try like below?

myId:number;//declare a global variable

constructor(){
   this.myId=this.navParams.get('id');
   this.categoryRef = this.db.list('/category', ref => 
           ref.orderByChild('id').equalTo(this.myId));
   this.category = this.categoryRef.snapshotChanges().map(changes => {
           return changes.map(c => ({ key: c.payload.key, ...c.payload.val() }));
});
}

Answer 2

Actually I found an issue on firebase database side. My id was not stored with double quotes like "1" it was saved as 1 then I make it to double quotes and it works fine then