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Can a foreign key be NULL and/or duplicate?
...als. Suppose further that each proposal only has one sales person assigned and one client. So your proposal table would have two foreign keys, one with the client ID and one with the sales rep ID. However, at the time the record is created, a sales rep is not always assigned (because no one is fre...
What is in your Mathematica tool bag? [closed]
...ned this before, but the tool I find most useful is an application of Reap and Sow which mimics/extends the behavior of GatherBy:
SelectEquivalents[x_List,f_:Identity, g_:Identity, h_:(#2&)]:=
Reap[Sow[g[#],{f[#]}]&/@x, _, h][[2]];
This allows me to group lists by any criteria and tran...
How can I debug a .BAT script?
... The thing is, I have a build script , which calls a lot of other scripts, and I would like to see what is the order in which they are called, so that I may know where exactly I have to go about and add my modifications.
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Difference between return and exit in Bash functions
What is the difference between the return and exit statement in Bash functions with respect to exit codes?
10 Answers
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Do htmlspecialchars and mysql_real_escape_string keep my PHP code safe from injection?
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When it comes to database queries, always try and use prepared parameterised queries. The mysqli and PDO libraries support this. This is infinitely safer than using escaping functions such as mysql_real_escape_string.
Yes, mysql_real_escape_string is effectively just a ...
What are the obj and bin folders (created by Visual Studio) used for?
I created a new project in Visual Studio 2010 and noticed that there are now two new folders named obj and bin in my project directory.
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Is there any use for unique_ptr with array?
...ocators. Some people need a dynamically sized array, so std::array is out. And some people get their arrays from other code that is known to return an array; and that code isn't going to be rewritten to return a vector or something.
By allowing unique_ptr<T[]>, you service those needs.
In sh...
Angular JS: What is the need of the directive’s link function when we already had directive’s contro
I need to perform some operations on scope and the template. It seems that I can do that in either the link function or the controller function (since both have access to the scope).
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What is the leading LINQ for JavaScript library? [closed]
... really the same as linq to objects. (If it was, why would we need both Rx and Linq to Objects in .NET?) It works in the opposite direction to normal Linq in terms of the flow of data.
– Daniel Earwicker
Mar 23 '10 at 8:24
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Difference between Pig and Hive? Why have both? [closed]
...y background - 4 weeks old in the Hadoop world. Dabbled a bit in Hive, Pig and Hadoop using Cloudera's Hadoop VM. Have read Google's paper on Map-Reduce and GFS ( PDF link ).
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