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“Insert if not exists” statement in SQLite
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If you have a table called memos that has two columns id and text you should be able to do like this:
INSERT INTO memos(id,text)
SELECT 5, 'text to insert'
WHERE NOT EXISTS(SELECT 1 FROM memos WHERE id = 5 AND text = 'text to insert');
If a record already contains a row where ...
dplyr: “Error in n(): function should not be called directly”
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I presume you have dplyr and plyr loaded in the same session. dplyr is not plyr. ddply is not a function in the dplyr package.
Both dplyr and plyr have the functions summarise/summarize.
Look at the results of conflicts() to see masked objects.
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Fill SVG path element with a background-image
...100" height="100" />
</pattern>
</defs>
Adjust the width and height according to your image, then reference it from the path like this:
<path d="M5,50
l0,100 l100,0 l0,-100 l-100,0
M215,100
a50,50 0 1 1 -100,0 50,50 0 1 1 100,0
M265,50
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How to get started on TDD with Ruby on Rails? [closed]
...have' not required.
Once I've got all my testing classes how do I go and deploy them?
Not sure about the question. You don't usually deploy the tests. Once you have all your testing classes simple type 'rake test' to run all your tests.
How time consuming TDD really is?
It saves time ...
Reason to Pass a Pointer by Reference in C++?
...hat the user of that class could get a pointer to the internal data buffer and read/write to it, but it cannot – for example – free that buffer using delete or rebind that pointer to some other place in memory? Or did I get it wrong?
– BarbaraKwarc
Aug 4 '1...
what's data-reactid attribute in html?
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There's no way to share the actual object references between the server and the client and sending a serialized version of the entire component tree is potentially expensive. When the application is rendered at the server and React is loaded at the client, the only data it has are the data-reacti...
How to create custom exceptions in Java? [closed]
... it:
public void calculate(int i) throws FooException, IOException;
... and code calling this method must either handle or propagate this exception (or both):
try {
int i = 5;
myObject.calculate(5);
} catch(FooException ex) {
// Print error and terminate application.
ex.printStackTrace()...
Unable to Connect to GitHub.com For Cloning
...t repository , but I am getting the following message when I enter the command in my Git Bash:
5 Answers
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Can I tell the Chrome script debugger to ignore jquery.js?
...ssible in Firefox
https://developer.mozilla.org/en-US/docs/Tools/Debugger
And in Chrome Canary using Experimental Dev tools.
http://www.divshot.com/blog/tips-and-tricks/ignoring-library-code-while-debugging-in-chrome/
Update. In Chrome v.75 there is a separabe tab for blackboxing.
Above works in ...
Git: How to reuse/retain commit messages after 'git reset'?
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When running "git commit" command, you've to check the following options,
To reuse,
--reuse-message=<commit>
To edit on reuse,
--reedit-message=<commit>
To change the author,
--reset-author
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