如何更新文档内部的arrayList?

时间:2019-07-13 19:56:04

标签: java android firebase google-cloud-firestore

当我要在用户文档中更新recipIds数组列表时,将擦除数组列表并设置新值。

我试图获取旧的收藏,然后向其添加新的价值并进行更新,但这似乎有些过分。

public void saveRecipeIds(User user) {
    String currentUserId = mAuth.getCurrentUser().getUid();

    Map<String, Object> userMap = new HashMap<>();
    userMap.put("recipeIds", user.getRecipesIds());

    db.collection("users").document(currentUserId).update(userMap);
}

我想用新值更新我的数组列表,而又不清除旧列表数据。

这是在Firestore中的外观:

https://imgur.com/a/LUnYxsa

编辑:

public void saveRecipeIds(User user) {
    String currentUserId = mAuth.getCurrentUser().getUid();

    Map<String, Object> userMap = new HashMap<>();
    userMap.put("recipeIds", user.getRecipesIds());

    db.collection("users").document(currentUserId)
        .update("recipeIds", FieldValue.arrayUnion(userMap));
}

https://imgur.com/a/yTywInK

已编辑

public void saveRecipeIds(User user) {
    String currentUserId = mAuth.getCurrentUser().getUid();

//  Map<String, Object> userMap = new HashMap<>();
//  userMap.put("recipeIds", user.getRecipesIds());

    db.collection("users").document(currentUserId)
        .update("recipeIds", FieldValue.arrayUnion(user.getRecipesIds()));
}

错误:

java.lang.IllegalArgumentException: Invalid data. Nested arrays are not supported
        at com.google.firebase.firestore.core.UserData$ParseContext.createError(com.google.firebase:firebase-firestore@@18.2.0:293)
        at com.google.firebase.firestore.UserDataConverter.parseData(com.google.firebase:firebase-firestore@@18.2.0:261)
        at com.google.firebase.firestore.UserDataConverter.convertAndParseFieldData(com.google.firebase:firebase-firestore@@18.2.0:202)
        at com.google.firebase.firestore.UserDataConverter.parseArrayTransformElements(com.google.firebase:firebase-firestore@@18.2.0:440)
        at com.google.firebase.firestore.UserDataConverter.parseSentinelFieldValue(com.google.firebase:firebase-firestore@@18.2.0:346)
        at com.google.firebase.firestore.UserDataConverter.parseData(com.google.firebase:firebase-firestore@@18.2.0:248)
        at com.google.firebase.firestore.UserDataConverter.convertAndParseFieldData(com.google.firebase:firebase-firestore@@18.2.0:202)
        at com.google.firebase.firestore.UserDataConverter.parseUpdateData(com.google.firebase:firebase-firestore@@18.2.0:176)
        at com.google.firebase.firestore.DocumentReference.update(com.google.firebase:firebase-firestore@@18.2.0:213)
        at com.example.cookingapp.Repository.UserRepository.saveRecipeIds(UserRepository.java:143)
        at com.example.cookingapp.ViewModels.UserViewModel.saveRecipeIds(UserViewModel.java:57)
        at com.example.cookingapp.Views.Fragments.Home.FinishRecipeFragment$1.onClick(FinishRecipeFragment.java:111)
        at android.view.View.performClick(View.java:6199)
        at android.widget.TextView.performClick(TextView.java:11090)
        at android.view.View$PerformClick.run(View.java:23647)
        at android.os.Handler.handleCallback(Handler.java:751)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:154)
        at android.app.ActivityThread.main(ActivityThread.java:6682)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1520)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1410)

1 个答案:

答案 0 :(得分:2)

要更新recipeIds数组,您应该像下面的代码行一样使用FieldValue.arrayUnion

db.collection("users").document(currentUserId)
    .update("recipeIds", FieldValue.arrayUnion("newRecipeId"));

编辑:

为了能够更新数组(例如,通过添加新元素),您需要将字符串(id本身)传递给arrayUnion()方法。您无法传递列表或字符串数​​组。您无法做到这一点。您可以一个一个地添加/删除数组中的元素。

如果要使用另一个阵列更新该阵列,则应首先从数据库中获取文档,在客户端进行必要的更改,然后将其写回到数据库中。