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mongodb count num of distinct values per field/key
Is there a query for calculating how many distinct values a field contains in DB.
5 Answers
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Remove 'a' from legend when using aesthetics and geom_text
How can I can remove the letter 'a' from the legend generated by this code? If I remove the geom_text , then the 'a' letter will not show in the legend. I want to keep geom_text , though.
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How do I find which program is using port 80 in Windows? [duplicate]
... Then you either need to watch through list carefully or install some additional software. technet.microsoft.com/en-us/sysinternals/bb897437.aspx for example.
– n0rd
Dec 25 '09 at 8:14
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How to refresh app upon shaking the device?
...trong "shake" when the application starts and "hits" the ground from free-fall. However, the code gets used to the gravitation due to the low-cut filter and would work also on other planets or in free space, once it is initialized.
(you never know how long your application will be in use...;-)
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What techniques can be used to define a class in JavaScript, and what are their trade-offs?
... this.name = name;
this.gender = gender;
}
// Add methods like this. All Person objects will be able to invoke this
Person.prototype.speak = function(){
alert("Howdy, my name is" + this.name);
};
// Instantiate new objects with 'new'
var person = new Person("Bob", "M");
// Invoke methods...
What's the difference between “squash” and “fixup” in Git/Git Extension?
I've been using Git Extensions for a while now (it's awesome!) but I haven't found a simple answer to the following:
6 An...
Vsphere 6 集群上 安装 oracle rac 遇到的共享磁盘故障 - 数据库(内核) - ...
...联系上了原厂工程师。
对了我们购买的VMWARE 是联想的OEM版，直接联系VMWARE是没有卵用的。必须经过联想。
关于配置Oracle RAC最佳配置参考VMware文档。
文档链接：http://www.vmware.com/files/pdf/solutions/oracle/Oracle_Databases_VMware_RAC_Deployme...
What's the difference between Perl's backticks, system, and exec?
...It never returns true, because if the command is found it never returns at all.
There is also no point in returning STDOUT, STDERR or exit status of the command.
You can find documentation about it in perlfunc,
because it is a function.
system
executes a command and your Perl script is con...
Difference between rake db:migrate db:reset and db:schema:load
...drop, db:setup
db:migrate:reset does db:drop, db:create, db:migrate
Typically, you would use db:migrate after having made changes to the schema via new migration files (this makes sense only if there is already data in the database). db:schema:load is used when you setup a new instance of your app...
Vim: insert the same characters across multiple lines
...e the screen in the first line - until Esc is pressed (6.), at which point all lines will be updated.
Press Esc.
An uppercase I must be used rather than a lowercase i, because the lowercase i is interpreted as the start of a text object, which is rather useful on its own, e.g. for selecting insi...