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Difference between Key, Primary Key, Unique Key and Index in MySQL
...would use indexes to improve the speed of data retrieval. An index is typically created on columns used in JOIN, WHERE, and ORDER BY clauses.
Imagine you have a table called users and you want to search for all the users which have the last name 'Smith'. Without an index, the database would have t...
How to impose maxlength on textArea in HTML using JavaScript
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@JoshStodola - Indeed you cannot. It would really annoy me as a user if I had pasted a whole piece of something in a textarea, clicked submit, and only saw a small portion of it go through without any response.
– Travis J
Apr 30 '1...
PATH issue with pytest 'ImportError: No module named YadaYadaYada'
I used easy_install to install pytest on a mac and started writing tests for a project with a file structure likes so:
20 A...
MySQL vs MongoDB 1000 reads
...very excited about MongoDb and have been testing it lately. I had a table called posts in MySQL with about 20 million records indexed only on a field called 'id'.
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Where can I find my Facebook application id and secret key?
...n my Facebook account, where can I find these application IDs, secret key, all?
7 Answers
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Convert boolean result into number/integer
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@DerkJanSpeelman The fact that something is not allowed in Typescript does not mean that you shouldn't do it in Javascript. They are different (albeit related) languages.
– lonesomeday
Dec 9 '19 at 17:14
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What are the best practices for using a GUID as a primary key, specifically regarding performance?
I have an application that uses GUID as the Primary Key in almost all tables and I have read that there are issues about performance when using GUID as Primary Key. Honestly, I haven't seen any problem, but I'm about to start a new application and I still want to use the GUIDs as the Primary Keys, b...
isset() and empty() - what to use
... check - is variable empty or contains something. To solve this task, I usually do the following.
6 Answers
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Working with time DURATION, not time of day
... cell B2 and drag as far down as the A column goes to apply the formula to all data in col A.
Last step, be sure to highlight all of column B and set it to Number format (the application of the formula may have automatically set format to Time).
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What is the most frequent concurrency issue you've encountered in Java? [closed]
...are not synchronized this is not guaranteed to work. This mistake is especially devilish as in 99.999% it won't matter in practice as the reader thread will eventually see the change - but we don't know how soon he saw it.
s...