Firebase数据库使用setValue()覆盖以前的值 [英] Firebase Database overwrites previous value with setValue()

问题描述

所以我在Firebase中有一个数据库.

So I have a Database in Firebase.

此代码在onCreate()中:

This code is in onCreate():

DatabaseReference mDatabaseRefUser =FirebaseDatabase.getInstance().getReference("Users");

此代码在另一个称为onClick的方法中

This code is in another method that gets called onClick:

mDatabaseRefUser.child("Chat").child(mAuth.getCurrentUser().getUid())
            .child(userID).child(uploadID).child("Messages").push().setValue(new ChatMessage(addMessageEditText.getText().toString(),
            mAuth.getCurrentUser().getEmail()));

mDatabaseRefUser.child("Chat").child(userID)
            .child(mAuth.getCurrentUser().getUid()).child(uploadID).child("Messages").push().setValue(new ChatMessage(addMessageEditText.getText().toString(),
            userEmail));

我试图做的是在每次调用该方法时添加一个新值，而不删除先前/现有的值.

What im trying to do is to add a new value without deleting the previous/existing value everytime the method gets called.

就在我每次单击并启动方法时，先前/现有的值都将被删除，而新值将被添加.但是我都不希望被删除.我希望这个新值也能被添加.我已经尝试过使用getRef和push()，但是我的数据仍然被覆盖.我在这里做什么错了?

For the moment everytime I click and start the method, the previous/existing value gets removed and the new one gets added. But I want neither to be deleted. I want this the new value to be added aswell. I have tried with getRef and push() but my data still gets overwritten. What am I doing wrong here?

这是我第一次调用JSON方法:

This is my JSON 1st time I call the method:

"Users" : {
"Chat" : {
  "Xta3jwm4yLQWaJBypMBFt2esiOr2" : {
    "xfqAFlRpbUZRlZb76svN5FUtbU93" : {
      "-LCvIA_9L1Y9rjkm96Aj" : {
        "Messages" : {
      "-LCvqDidnNqQ8ALZhDud" : {
        "messageText" : "Very good",
        "messageTime" : 1526791230552,
        "messageUser" : "[e-mail]"
      }
    },
    "chatAgainstUserEmail" : "[e-mail]",
    "chatAgainstUserID" : "xfqAFlRpbUZRlZb76svN5FUtbU93",
    "uploadID" : "-LCvIA_9L1Y9rjkm96Aj",
    "userEmail" : "[e-mail]",
    "userID" : "Xta3jwm4yLQWaJBypMBFt2esiOr2"
  }
}

},
  "xfqAFlRpbUZRlZb76svN5FUtbU93" : {
"Xta3jwm4yLQWaJBypMBFt2esiOr2" : {
  "-LCvIA_9L1Y9rjkm96Aj" : {
    "Messages" : {
      "-LCvqDigI8ZwHDYuPhw9" : {
        "messageText" : "Very good",
        "messageTime" : 1526791230555,
        "messageUser" : "[e-mail]"
      }
    },
    "chatAgainstUserEmail" : "[e-mail]",
    "chatAgainstUserID" : "Xta3jwm4yLQWaJBypMBFt2esiOr2",
    "uploadID" : "-LCvIA_9L1Y9rjkm96Aj",
    "userEmail" : "[e-mail]",
    "userID" : "xfqAFlRpbUZRlZb76svN5FUtbU93"
      }
    }
  }
}

这是我第二次调用它的JSON

This is my JSON when I call it for the 2nd time

"Users" : {
"Chat" : {
  "Xta3jwm4yLQWaJBypMBFt2esiOr2" : {
    "xfqAFlRpbUZRlZb76svN5FUtbU93" : {
      "-LCvIA_9L1Y9rjkm96Aj" : {
        "Messages" : {
      "-LCvr0zoHOPxsKOVJzeu" : {
        "messageText" : "Very good 2nd call",
        "messageTime" : 1526791440547,
        "messageUser" : "[e-mail]"
      }
        },
    "chatAgainstUserEmail" : "[e-mail]",
    "chatAgainstUserID" : "xfqAFlRpbUZRlZb76svN5FUtbU93",
    "uploadID" : "-LCvIA_9L1Y9rjkm96Aj",
    "userEmail" : "[e-mail]",
    "userID" : "Xta3jwm4yLQWaJBypMBFt2esiOr2"
  }
}
  },
  "xfqAFlRpbUZRlZb76svN5FUtbU93" : {
"Xta3jwm4yLQWaJBypMBFt2esiOr2" : {
  "-LCvIA_9L1Y9rjkm96Aj" : {
    "Messages" : {
      "-LCvr0zrh8wQ2WurUezs" : {
        "messageText" : "Very good 2nd call",
        "messageTime" : 1526791440550,
        "messageUser" : "[e-mail]"
      }
    },
    "chatAgainstUserEmail" : "[e-mail]",
    "chatAgainstUserID" : "Xta3jwm4yLQWaJBypMBFt2esiOr2",
    "uploadID" : "-LCvIA_9L1Y9rjkm96Aj",
    "userEmail" : "[e-mail]",
    "userID" : "xfqAFlRpbUZRlZb76svN5FUtbU93"
      }
    }
  }
}

我也尝试过使用getRef().push()，但是那也不起作用.我也尝试了没有.getRef()和没有.push()的情况，也没有用.

I have also tried with getRef().push(), but that didn't work either. I have also tried without .getRef() and without .push(), didnt work either.

推荐答案

我对此问题的唯一解决方案是创建一个新数据库，

My only solution to this issue was to make a new Database,

我添加了这个:

mDatabaseRefUser.child("Chatting").child(mAuth.getCurrentUser().getUid())
                .child(userID).child(uploadID).child("Messages").push().setValue(new ChatMessage(addMessageEditText.getText().toString(),
                mAuth.getCurrentUser().getEmail()));

        mDatabaseRefUser.child("Chatting").child(userID)
                .child(mAuth.getCurrentUser().getUid()).child(uploadID).child("Messages").push().setValue(new ChatMessage(addMessageEditText.getText().toString(),
                userEmail));

并删除了旧的

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