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In Firebase, is there a way to get the number of children of a node without loading all the node dat
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The code snippet you gave does indeed load the entire set of data and then counts it client-side, which can be very slow for large amounts of data.
Firebase doesn't currently have a way to count children without loading data, but we do plan to add it.
For now, one solution would be to mai...
Referencing another schema in Mongoose
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what would be the difference between populate and addToSet?
– Winnemucca
Apr 23 '17 at 6:50
1
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Maintain the aspect ratio of a div with CSS
...rce: w3.org, emphasis mine)
Padding-bottom values for other aspect ratios and 100% width :
aspect ratio | padding-bottom value
--------------|----------------------
16:9 | 56.25%
4:3 | 75%
3:2 | 66.66%
8:5 | 62.5%
Placing content in ...
How to copy a dictionary and only edit the copy
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It might be better to say "dict2 and dict1 point to the same dictionary", you are not changing dict1 or dict2 but what they point to.
– GrayWizardx
Mar 17 '10 at 21:15
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How to use setInterval and clearInterval?
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setInterval sets up a recurring timer. It returns a handle that you can pass into clearInterval to stop it from firing:
var handle = setInterval(drawAll, 20);
// When you want to cancel it:
clearInterval(handle);
handle = 0; // I just do this so I know I've cleared the interv...
How to add not null constraint to existing column in MySQL
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Just use an ALTER TABLE... MODIFY... query and add NOT NULL into your existing column definition. For example:
ALTER TABLE Person MODIFY P_Id INT(11) NOT NULL;
A word of caution: you need to specify the full column definition again when using a MODIFY query. If you...
Animate a custom Dialog
...g="utf-8"?>
<resources>
<style name="PauseDialog" parent="@android:style/Theme.Dialog">
<item name="android:windowAnimationStyle">@style/PauseDialogAnimation</item>
</style>
<style name="PauseDialogAnimation">
<item name="android...
Ship an application with a database
...();
}
public void test(){
try{
String query ="SELECT value FROM test1";
Cursor cursor = database.rawQuery(query, null);
if (cursor.moveToFirst()){
do{
String value = cursor.getString(0);
Log....
C#操作XML小结 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...odes[i]);
//为指定节点的新建属性并赋值
node.SetAttribute("id","11111");
//为指定节点添加子节点
root.AppendChild(node);
//获取指定节点的指定属性值
string id=node.Attributes["id"].Value;
//获取指定节点中的文本
string content=node.InnerText;
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Adding and removing style attribute from div with jquery
I've inherited a project I'm working on and I'm updating some jquery animations (very little practice with jquery).
7 Answe...