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Many-to-many relationship with the same model in rails?

...schema for your posts: create_table "posts", :force => true do |t| t.string "name", :null => false end For any many-to-many relationship, you need a join table. Here's the schema for that: create_table "post_connections", :force => true, :id => false do |t| t.integer "post_a_id"...
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How are parameters sent in an HTTP POST request?

In an HTTP GET request, parameters are sent as a query string : 8 Answers 8 ...
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Simple logical operators in Bash

... a variable is empty and -e $file to test if a file exists. There are also string equality operators: "$string1" == "$string2" (beware that the right-hand side is a pattern, e.g. [[ $foo == a* ]] tests if $foo starts with a while [[ $foo == "a*" ]] tests if $foo is exactly a*), and the familiar !, &...
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Sleeping in a batch file

... UPDATE The timeout command, available from Windows Vista and onwards should be the command used, as described in another answer to this question. What follows here is an old answer. Old answer If you have Python installed, or don't mind installing...
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Using Java 8's Optional with Stream::flatMap

...de() { return optional.hashCode(); } @Override public String toString() { return optional.toString(); } } You will see that I added flatStream(), as here: public Stream<T> flatStream() { if (!optional.isPresent()) { return Stream.empty(); } ...
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What is the difference between ArrayList.clear() and ArrayList.removeAll()?

Assuming that arraylist is defined as ArrayList<String> arraylist , is arraylist.removeAll(arraylist) equivalent to arraylist.clear() ? ...
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What is the motivation for bringing Symbols to ES6?

...t that the :symbol notion in Ruby is needless; we could easily use plain strings instead, like we do in JavaScript. And now they decide to complicate things in JS with that. ...
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Convert integer to binary in C#

... Your example has an integer expressed as a string. Let's say your integer was actually an integer, and you want to take the integer and convert it to a binary string. int value = 8; string binary = Convert.ToString(value, 2); Which returns 1000. ...
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How to use the 'main' parameter in package.json?

...mary entry point to your program. That is, if your package is named foo, and a user installs it, and then does require("foo"), then your main module's exports object will be returned. This should be a module ID relative to the root of your package folder. For most modules, it makes...
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How to convert SQL Query result to PANDAS Data Structure?

... Here's the shortest code that will do the job: from pandas import DataFrame df = DataFrame(resoverall.fetchall()) df.columns = resoverall.keys() You can go fancier and parse the types as in Paul's answer. ...