如何使用orderBy()和Where()相同?(颤振网) [英] how to use orderBy() and Where() same? (Flutter Web)

问题描述

不加载数据，但无限期加载♾如果我起飞OrderBy，那么它可以工作但我需要订购者

代码:

  body:StreamBuilder< QuerySnapshot>(流:FirebaseFirestore.instance.collection(粉碎").where("user"，isEqualTo:user.email).orderBy("date"，降序:true).snapshots()，建造者:(BuildContext上下文，AsyncSnapshot< QuerySnapshot>快照){如果(！snapshot.hasData){ 

解决方案

当您执行这样的复合查询时，您需要创建的"Firestore"部分.>

• 转到索引标签，然后点击创建索引.

• 输入集合名称，并设置要用来对索引进行排序的字段.

对于非数组和非地图字段，即使您不需要该字段进行排序，也必须选择升序或降序.您的选择不会影响查询中的平等行为.

• 点击创建.

Not load data but it loads indefinitely ♾ if i take off OrderBy then it works but I need the Order by

code:

body: StreamBuilder<QuerySnapshot>(
      stream: FirebaseFirestore.instance
          .collection("crush")
          .where("user", isEqualTo: user.email)
          .orderBy("date", descending: true)
          
          .snapshots(),
      builder:
          (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
        if (!snapshot.hasData) {

解决方案

When you do composite query like this you need to create composite index. There are two ways to create index for it:

Create index using error message:

---

When you try to use a compound query without existing index, you will get an error in your debug console like this:

E/flutter (23618): [ERROR:flutter/lib/ui/ui_dart_state.cc(177)] Unhandled Exception: [cloud_firestore/failed-precondition] The query requires an index. You can create it here: https://console.firebase.google.com/v1/r/project/yourprojectname/firestore/indexes?create_composite=Ck1wcm9qZWN0cy92b2lkY2hhdGJldGEvZGF0YWJhc2VzLyhkZWZhdWx0KS9jb2xsZWN0aW9uR3JvdXBzL2NvbnRhY3RzL2luZGV4ZXMvXxABGgsKB3VzZW5hbWUQARoGCgJpZBABGgwKCF9fbmFtZV9fEAE

this error have a link to create a missing index with Firebase console. Follow this link, check data and click create.

Manually create index with Firebase console:

---

• Go to Firestore section of Firebase Console.

• Go to indexes tab and click Create Index.

• Enter the collection name and set the fields you want to order the index by.

For non-array and non-map fields, you must select ascending or descending ordering, even if you don't need the field for ordering. Your choice doesn't impact the behavior of equalities in the query.

• Click Create.

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