Sorry if that question was already asked but I didn't find any answer on google. I would like to know if it's dangerous to let users know data ids. For instance, if a user has as primary key in my data table "users" id=34.  Is it bad, to let him know that in the html/js code ? Is it recommended to hash data ids ? Which method is usually used in php ?  Thanks a lot for your response
I've heard that exposing database IDs (in URLs, for example) is a security risk, but I'm having trouble understanding why.  Any opinions or links on why it's a risk, or why it isn't?  EDIT: of course the access is scoped, e.g. if you can't see resource foo?id=123 you'll get an error page. Otherwise the URL itself should be secret.  EDIT: if the URL is secret, it will probably contain a generated token that has a limited lifetime, e.g. valid for 1 hour and can only be used once.  EDIT (months later): my current preferred practice for this is to use UUIDS for IDs and expose them. If I'm using sequential numbers (usually for performance on some DBs) as IDs I like generating a UUID token for each entry as an alternate key, and expose that.
Should "State" be capitalized on its own? Say we had the following:     Higher Education spending, clout, and influence in New York State is substantial. Within the State’s borders...   Should the latter instance of State be capitalized or not? How can I script the settings made by gnome-tweak-tool? I like to be able to configure things from the command line, so that when I reinstall the OS I can just run a script and get my preferred configuration back.  Since "upgrading" to Ubuntu 17.10, I found I had to use gnome-tweak-tool to get some settings the way I want them.  Once I find a setting in the gnome-tweak-tool GUI, how can I figure out its scriptable translation?  For example the following gsettings lines match the relevant entries in the gnome-tweak-tool screen shot below...  gsettings set org.gnome.desktop.wm.preferences titlebar-font "Tahoma Bold 8" gsettings set org.gnome.desktop.interface font-name "Tahoma 8" gsettings set org.gnome.desktop.interface document-font-name "Tahoma 8" gsettings set org.gnome.desktop.interface monospace-font-name "FixedSC 10"    ...but how could anyone guess that? And how would I, for example, figure out where to get the corresponding settings for hinting and antialiasing? How to show the parent and child taxonomy term? Changing an element's ID with jQuery I am a UI designer and developer and have been designing websites for aound 10 years. I want to get into user experience design. I know how to do a design, but I am lagging the terminologies and the technical things in the user experience field.   So how do I go about getting the skills and mindset necessary for being a User Experience Designer? English (other than American English) has a clear differentiation between the two words. Both are about translocating something. In "bring" the something of somebody is moved to where the speaker is currently situated. "Take" is used to translocate something or somebody to a place that the speaker is not currently at.   You cannot “bring” your books to school if you are currently at home. You can only take them to school. Most of the time one can get the meaning from the context of the sentence but it can get very confusing when the other party is on the telephone and you do not know their location.   Why does American English not differentiate and when did it lose the differentiation? Find files using ls and wildcards pwd : ../bin under bin I have a directory called datafiles.  Use meta characters and the ls -lL command (with lower and upper case L) to list all filenames under the datafiles directory that contain a dot . with the letter 'f' or 'u' anywhere after the dot.  I tried: ls -lL datafiles *.*f*u  ls -lL datafiles .[f*u]     Thank you for answering. Unfortunately, none of the solutions worked the way I wanted it.  By clarifying the question, /bin/datafiles/file.backup is the root to the directory. From the /bin directory, the command I used is ls -lL datafiles followed by meta characters.  I'm looking for file.backup that has a dot and followed by f or u, not directly followed by f or u (anywhere after the dot), and not ending by f or u. How do I setup an encrypted swap file? When I installed Ubuntu, I setup an encrypted home partition. Now I have come to an issue where I am running out of memory because I haven't setup swap. How can I setup an encrypted swap file?  A couple of times while booting I've seen some reference to cryptswap. I've also got these lines contained in /etc/fstab  # swap was on /dev/sda6 during installation #UUID=1ba8a53b-1842-4de7-8e38-2d6c79f3a1ab none            swap    sw              0       0 /dev/mapper/cryptswap1 none swap sw 0 0 Which view is the "Current view"? I have got a SharePoint 2010 website with a WebPart-page and a few WebParts on it.  One of the WebParts displays a list/a view of a list.  The views of that list have been updated due to business needs - but the view in the WebPart on the WebPart-page is not updated.    If I edit "Modify Shared Web Part" (the one with the list / list view),  the "Selected view" is set to "&lt;Current view&gt;".  My question is now: Which view of the list is the "&lt;Current view&gt;"? Is it any view of the list at all - or has the WebPart some kind of its own view to that list? To show that either $R$ is a field or $R$ is a finite ring with prime number of elements and $ab = 0$ for all $a,b \in R$. relative polar coordinates for TikZ elements in axis environment I would like to annotate a patch plot with lines whose start and end points are given in absolute polar and relative polar coordinates, respectively.  The patch plot, based on cartesian data, comes out as a circular shape centred around the origin (0,0) and shall be simulated here by a plain circle.  Lines should start at the circumference of the shape and point away from the shape under a given angle and have a well defined length. Therefore, the use of relative polar coordinates for the line's end point.  What seems to be straightforward with TikZ (left) fails inside the axis environment of pgfplots (right): neither the inclination angle nor the length of the line are correct if relative polar coordinates are used.    What is wrong with the rel. polar coordinates here?  The code:  \documentclass{standalone}  \usepackage{pgfplots} \pgfplotsset{compat=1.13}  \begin{document}  \begin{tikzpicture}   \draw(0,0) circle[radius=0.01];   \draw[blue] (0,0) circle[radius=1];   \draw[thick] (45:1) -- ++(45:0.5); \end{tikzpicture}  \begin{tikzpicture}   \begin{axis}[tiny,enlargelimits,   axis equal,   xmin=-2,xmax=2,   ymin=-1,ymax=1,   xtick={-2,-1,0,1,2},   ytick={-2,-1,0,1,2},   grid=major,   ]   \draw[blue] (0,0) circle[radius=1];   \draw[blue, dashdotted] (0,0) -- (45:2);   \draw[thick] (45:1) -- ++(45:0.5); %  \draw[thick] (45:1) -- (45:1.5); %absolute coordinates do work   \end{axis} \end{tikzpicture}  \end{document} When is an Integer a Rational Number, and are All Ratios Rational, Even $\frac{\sqrt{7}}{2}$? $$\Bbb{Q} = \left\{\frac ab \mid \text{$a$ and $b$ are integers and $b \ne 0$} \right\}$$ In other words, a rational number is a number that can be written as one integer over another. For an integer, the denominator is $1$ in that case. For example, $5$ can be written as $\dfrac 51$.  Is $5$ a rational number? Or is $\dfrac 51$  a rational number? I'm not able to figure out what the definition is actually saying. What are the numbers that cannot be written as one integer over another?  Irrational numbers are the numbers that cannot be written as one integer over another. Roots of numbers that are not perfect squares are examples of irrational numbers.  However, what is this then: $\dfrac {\sqrt 7} {2}$? Does Windows still rely on MS-DOS? I am just about to start an OS course and as an Apple user I am not very familiar with the underlying details of Windows OS. I was wondering, is MS DOS still used with Windows running on top or is ONLY Windows used now as the OS? I was a little confused because I read somewhere that MS-DOS is used for booting but Windows has all other OS capabilities built into it and thus is used for all other OS operations... Date Not Saving in Mysql from Php Registration Form Subject/Complement Agreement. How to describe problem with "The thing is the objects." In my , I provided the following, problematic,  wording (especially bold italic), and I need help to better understand this issue so I can fix my answer:1          The thing is the books. (Reduced form of Sentence 2.a)         Fundamentally, Sentence 2.a (the so-called "correct" answer), is grammatically defective. Recall there is another grammatical rule: the subject and subject's complement should match in number.    A clarification is needed here. I am not suggesting here, in this EL&amp;U question, that there is any such singular grammatical rule as indicated in the quote above.  The quote continues as follows:     The reduced sentence makes the disagreement between the subject's and complement's plurality obvious. What is one to do? Language is linear and we know "The thing is X" is better than "The thing are X", so we go with the former, which is the subject-verb agreement rule. But what is "the books" then? It must be thought of as a collective noun, even if it doesn't look or feel like one. Forcing something to be a collective noun is related to the idea of notional agreement.   Others noted that grammatically defective is too strongly worded.  There is no such "grammatical rule" for subject/complement agreement.  Please help me understand/improve upon my line of thought here.  I'm stating that Sentence 2.1 presents a fundamental "conflict" or "error" (however one might define error) at some level (morphological, syntax, grammatical, semantic):     The thing is the books.  (Or, "The thing is the objects.")   Based on the "obvious" morphosyntactic plurality conflict, the above sentence feels so wrong that I think many native speakers would think it "simply" grammatically incorrect. However, @F.E. gives counter examples:     And here are some more grammatical examples, where the number of subject and predicative complement don't agree: "They were a problem to us all", "That so-called work of art is simply four pieces of driftwood glued together" (CGEL, page 254-5). As CGEL says: "What is required is semantic compatibility, not syntactic agreement . . .". There are more examples on page 512: "The only thing we need now is some new curtains", "The major asset of the team is its world-class opening bowlers", "Our neighbors are a nuisance", "This gadget is five different tools in one".   I think all the examples given above can be explained as notional agreement.    Question 1: If we explain this phenomena in terms of notional vs syntactic agreement, where does "grammatically correct/incorrect" fit in?  Question 2: Can a simple sentence such as "The thing is the objects." be grammatically incorrect while more complex sentences such as "The thing is four pieces of driftwood glued together." be grammatically correct?  (The answer, in my mind, must be no; this is my conundrum.)  Question 3: Would it be better to say that Sentence 2.a has a low level of (linguistic) ?   Question 4: How about a low level of  and that it's semantically difficult to be (linguistically) ?    Question 5: Do we simply draw a hard line and say "The thing is the objects." is 100% grammatically correct?  I didn't particularly like this option based on intuitive notions of "grammatically correct".    1. Please help me and be kind; I'm trying to improve my understanding. I'm looking for cool, objective advice on how to look at this.  I numbered my questions so they can be easily referenced, if desired.  My preference is the final answer would sufficiently answer all the questions, but of course that can be done explicitly or implicitly. How do I have no default web browser, so the system asks what browser to use when I click on a link? I use Internet Explorer for some things and Chrome for others. I'd like to have a choice when I click on a link of which browser to open the link in. Is this possible in Windows? I am currently running Windows 8, although there should be similarities between versions.  To the best of my knowledge this isn't possible. MySQL Seems to be crashing quite often, I'd say every hour or so.   The only thing running on this server that is using MySQL is a Drupal installation that I'm working on, there's only one person that's using it and it literally has around three pages - from what I can gather this seems to be a memory issue with innoDB? I'm not great at this stuff so I'm unsure.  Any guidance? Here's the relevant parts from my error.log  140216 14:20:01 [Note] Plugin 'FEDERATED' is disabled. 140216 14:20:01 InnoDB: The InnoDB memory heap is disabled 140216 14:20:01 InnoDB: Mutexes and rw_locks use GCC atomic builtins 140216 14:20:01 InnoDB: Compressed tables use zlib 1.2.3.4 140216 14:20:01 InnoDB: Initializing buffer pool, size = 128.0M InnoDB: mmap(135987200 bytes) failed; errno 12 140216 14:20:01 InnoDB: Completed initialization of buffer pool 140216 14:20:01 InnoDB: Fatal error: cannot allocate memory for the buffer pool 140216 14:20:01 [ERROR] Plugin 'InnoDB' init function returned error. 140216 14:20:01 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed. 140216 14:20:01 [ERROR] Unknown/unsupported storage engine: InnoDB 140216 14:20:01 [ERROR] Aborting  140216 14:20:01 [Note] /usr/sbin/mysqld: Shutdown complete  140216 14:20:02 [Note] Plugin 'FEDERATED' is disabled. 140216 14:20:02 InnoDB: The InnoDB memory heap is disabled 140216 14:20:02 InnoDB: Mutexes and rw_locks use GCC atomic builtins 140216 14:20:02 InnoDB: Compressed tables use zlib 1.2.3.4 140216 14:20:02 InnoDB: Initializing buffer pool, size = 128.0M InnoDB: mmap(135987200 bytes) failed; errno 12 140216 14:20:02 InnoDB: Completed initialization of buffer pool 140216 14:20:02 InnoDB: Fatal error: cannot allocate memory for the buffer pool 140216 14:20:02 [ERROR] Plugin 'InnoDB' init function returned error. 140216 14:20:02 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed. 140216 14:20:02 [ERROR] Unknown/unsupported storage engine: InnoDB 140216 14:20:02 [ERROR] Aborting  140216 14:20:02 [Note] /usr/sbin/mysqld: Shutdown complete   EDIT The server is the lowest-spec DigitalOcean Droplet with 512MB RAM. This particular Droplet is running NodeJS, MySQL and Apache. There's a low-traffic static site, a Ghost blog and this Drupal site I'm developing.   Should I just upgrade the RAM, or is there something I can do to fix this? Can I rent a camper in the US/Canada with a European B license? We are considering a holiday in North America with a camper. I have a European driver's license (B) which allows me to drive personal cars up to 3500 kg, although I can imagine that an average camper easily weighs more.  Does my license qualify me to drive a camper? If not, can I take an American/Canadian driver's test which would allow me to drive a camper? prime divisor of $3n+2$ proof I have to prove that any number of the form $3n+2$ has a prime factor of the form $3m+2$. Ive started the proof  I tried saying by the division algorithm the prime factor is either the form 3m,3m+1,3m+2.  Case 1: $3m$      suppose $3m$ does divide $3n+2$. That means $3mr=3n+2$ where $r$ is some integer. But we get $mr-n= 2/3$ and since $mr-n$ is an integer that's a contradiction. Thus $3m$ does not work.  Case 2: $3m+1$ Same argument here  Case 3: $3m+2$ By the fundamental theorem of arithmetic every integer is divisible by a prime. But not sure what to do from here. From official :     Due to a head injury, Cyclops is unable to shut off his optic blasts   at will and must therefore wear ruby quartz lenses to block the beams.   From the same page:     Cyclops possesses the mutant ability to project a beam of heatless   ruby-colored concussive force from his eyes, which act as   inter-dimensional apertures between this universe and another.   When his eyes are always blocked by ruby-colored beam of concussive force, how does he see?