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Create unique constraint with null columns
...ial indexes:
CREATE UNIQUE INDEX favo_3col_uni_idx ON favorites (user_id, menu_id, recipe_id)
WHERE menu_id IS NOT NULL;
CREATE UNIQUE INDEX favo_2col_uni_idx ON favorites (user_id, recipe_id)
WHERE menu_id IS NULL;
This way, there can only be one combination of (user_id, recipe_id) where menu_i...
How to concatenate twice with the C preprocessor and expand a macro as in “arg ## _ ## MACRO”?
I am trying to write a program where the names of some functions are dependent on the value of a certain macro variable with a macro like this:
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Pointers in C: when to use the ampersand and the asterisk?
...just starting out with pointers, and I'm slightly confused. I know & means the address of a variable and that * can be used in front of a pointer variable to get the value of the object that is pointed to by the pointer. But things work differently when you're working with arrays, strings or...
How to use PrimeFaces p:fileUpload? Listener method is never invoked or UploadedFile is null / throw
I'm trying to upload a file using PrimeFaces, but the fileUploadListener method isn't being invoked after the upload finishes.
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Chrome Extension how to send data from content script to popup.html
I know this this has been asked in numerous posts but honestly I don't get them. I am new to JavaScript, Chrome Extensions and everything and I have this class assignment.
So I need to make a plugin that would count DOM objects on any given page using Cross Domain Requests.
I've been able to achiev...
No ConcurrentList in .Net 4.0?
I was thrilled to see the new System.Collections.Concurrent namespace in .Net 4.0, quite nice! I've seen ConcurrentDictionary , ConcurrentQueue , ConcurrentStack , ConcurrentBag and BlockingCollection .
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How do popular apps authenticate user requests from their mobile app to their server?
...e confusion that I have is regarding how to sign-up/login the user first time and authenticate it every time they make a request to the API.
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What exactly is Hot Module Replacement in Webpack?
I've read a few pages about Hot Module Replacement in Webpack.
There's even a sample app that uses it .
2 Answers
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What is the difference between LL and LR parsing?
Can anyone give me a simple example of LL parsing versus LR parsing?
5 Answers
5
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Can I set max_retries for requests.request?
The Python requests module is simple and elegant but one thing bugs me.
It is possible to get a requests.exception.ConnectionError with a message like:
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