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What is the difference between single and double quotes in SQL?
...g in SQL. Double quotes generally aren't used in SQL, but that can vary from database to database.
Stick to using single quotes.
That's the primary use anyway. You can use single quotes for a column alias — where you want the column name you reference in your application code to be something ot...
Rails 4: List of available datatypes
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Here are all the Rails 4 (ActiveRecord migration) datatypes:
:binary
:boolean
:date
:datetime
:decimal
:float
:integer
:bigint
:primary_key
:references
:string
:text
:time
:timestamp
Source: http://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters/Sc...
Android destroying activities, killing processes
Hi I'm wondering how Android is managing memory and I can't find precise answer anywhere.
Let's assume I have an application with 5 activities on current activity stack (4 are stopped and 1 is resumed), there is no service connected. I press HOME button so that all of my activities are stopped.
I st...
MongoDB/NoSQL: Keeping Document Change History
A fairly common requirement in database applications is to track changes to one or more specific entities in a database. I've heard this called row versioning, a log table or a history table (I'm sure there are other names for it). There are a number of ways to approach it in an RDBMS--you can wri...
Get MD5 hash of big files in Python
I have used hashlib (which replaces md5 in Python 2.6/3.0) and it worked fine if I opened a file and put its content in hashlib.md5() function.
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How do I (or can I) SELECT DISTINCT on multiple columns?
I need to retrieve all rows from a table where 2 columns combined are all different. So I want all the sales that do not have any other sales that happened on the same day for the same price. The sales that are unique based on day and price will get updated to an active status.
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I want to execute shell commands from Maven's pom.xml
I want to execute Linux shell commands with Maven. Here is what I tried:
5 Answers
5
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Can I control the location of .NET user settings to avoid losing settings on application upgrade?
I'm trying to customize the location of the user.config file. Currently it's stored with a hash and version number
4 Ans...
Why doesn't C# support the return of references?
...of references, but C# doesn't. Is there a special reason? Why I can't do something like:
4 Answers
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Fatal Error: Allowed Memory Size of 134217728 Bytes Exhausted (CodeIgniter + XML-RPC)
I have a bunch of client point of sale (POS) systems that periodically send new sales data to one centralized database, which stores the data into one big database for report generation.
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