Unable to cast object of type 'System.DBNull' to type 'System.String'
Most efficient way to check for DBNull and then assign to a variable?
What's the best counter strategy against battlecruisers? How should I prepare my army when attacking someone who has 12+ battlecruisers? (Protoss/Zerg/Terran answers are more than appreciated) $X$ is a topological space with no special properties.  If a space $X$ has no isolated points, then show the same for any dense subset of   $X$.  Thanks a lot. Running own executable on Android shell I need a specific command line tool and I have made a C program in my Linux shell. I have compiled the program with an ARM cross-compiler. I have then moved the program into the Android file system and tried to run it.  The output is permission denied.  What do I have to do, in order to run my own compiled programs in Android file system? Should reputation from SO carry over to Meta? How do I run a GUI app via SSH? I have a large dictionary file with 300,000+ words in it and I'm trying to find all words with the vowels aeiou in that order and have only exactly 5 vowels. My current attempt does not seem to be working and for the life of me I don't understand why.  less mywords | grep -iE [^aeiou]*a[^aeiou]*e[^aeiou]*i[^aeiou]*o[^aeiou]*u[^aeiou]*   I think it get's all the words I'm looking for but there are a few words that pop up which I can not get rid of.  abstemiousnesses ultraserious   There are a few other but they are in the same vein. Curiously, even if I add something like [^u]* to the front ultraserious keeping popping back up! Any solution would be fine however I would like it restricted to grep as we've been told it can be done using only grep. I am new to Apex, but it is apparent to me that most (if not all) standard objects probably have an ID field. However, this field does not appear in the reference for the standard objects in the Soap API Developer's Guide. Instead, it reads:     To verify the complete list of fields for an object, you can use a   describe call from the API, or inspect with an appropriate tool, for   example, inspecting the WSDL or using a schema viewer.   If I want to find out for sure whether an object has an ID field, or what the field is named (is it ID, Identifier, id, etc), it sounds like I need to use a "describe call" or "an appropriate tool" or inspect the "WSDL" using a "schema viewer".  Now, I am an experienced software developer, but those solutions are so ambiguous I have no idea where to look next to figure out how to get an object's ID. Can anybody either refer me to more specific documentation, or explain how to find the complete field documentation via a "describe call", "appropriate tool", or "schema viewer"? Keeping tables/figures close to where they are mentioned Is there any package or a method to force LaTeX to keep floating environments like table and figure closer to where they are declared? I'm going on a vacation from Europe to the US and was planning of bringing along some Xbox360 or PS3 games, but now I'm curious if they will be compatible with my European Xbox.  In that past there would be a clear difference between NTSC and PAL games, but is this still the case with the current gen of consoles? I'm trying to split text in a JTextArea using a regex to split the String by \n However, this does not work and I also tried by \r\n|\r|n and many other combination of regexes. Code:  public void insertUpdate(DocumentEvent e) {     String split[], docStr = null;     Document textAreaDoc = (Document)e.getDocument();      try {         docStr = textAreaDoc.getText(textAreaDoc.getStartPosition().getOffset(), textAreaDoc.getEndPosition().getOffset());     } catch (BadLocationException e1) {         // TODO Auto-generated catch block         e1.printStackTrace();     }      split = docStr.split("\\n"); } Fix Accessibility of the sites on the leagues (and other pull downs that share the same code path) please The  site picker seems to be ordered on-site statistics instead of alphabetically:  This makes it very hard to find Photography, Physics, and Philosophy (for example) since they are nowhere near each other in the list. I’m open to a better solution, but as it stands, this feels a little too user-hostile to assume everyone is only interested in the first 3 to 5 top visible hits in the ordered list.  Scanning pages of unorganized contents is not optimal Keyboard input should filter and not just jump around  It also breaks accessibility when someone wishes to access the list from a keyboard (or a slower input control) as opposed to a mouse and visually. Pointer to class data member "::*" I came across this strange code snippet which compiles fine:  class Car {     public:     int speed; };  int main() {     int Car::*pSpeed = &amp;Car::speed;     return 0; }   Why does C++ have this pointer to a non-static data member of a class? What is the use of this strange pointer in real code? Which standard objects don't support triggers? PGFPlots: Understanding how to draw plots on different layers and arrange them I have gone through previous questions [,,], but I still couldn't figure out how to draw plots on different layers and change their order of drawing.  For this MWE, I would be grateful if I could figure out how to change the order of appearance of the three plots in such a way that the legend entries have the same order while keeping the plots commands/definitions in the same order as much as possible.  \RequirePackage{luatex85} \documentclass{standalone} \usepackage{pgfplots} \pgfplotsset{compat=newest}  \begin{document}  \begin{tikzpicture}     \begin{axis}[             legend style={                 at={([yshift=30pt]0.5,1)},                 anchor=north},             legend columns=-1,             xmin=0, xmax=10,             ymin=0, ymax=10,         ]         %         \addplot [red,      line width = 5pt,   domain=0:10]    {x}; \addlegendentry{$x$}            \addplot [black,    line width = 5pt,   domain=0:10]    {(x-5)^2}; \addlegendentry{$(x-5)^2$}         \addplot [yellow,   line width = 5pt,   domain=0:10]    {10-(x-5)^2}; \addlegendentry{$10-(x-5)^2$}     \end{axis} \end{tikzpicture}  \end{document} Why is the plural of "basis" "bases" and not "baseis"? Looking at the , it indicates that the plural is either bases or baseis.  It looks like the rare  comes from the Greek, but the common  just refers back to basis and that does not explain the plural etymology.  Is there a standard rule at work here, or is this just an exceptional case that arose over time by convention? In Radian mode, continually pressing the $\cos$ function of a number causes the result to converge to $x=0.739085133$, a fixed point of $\cos(x)$. Repeating this behavior with the $\sin$ function causes the result to converge to $x=0$, a fixed point of $\sin(x)$.   What happens if this is done using the tan function? It seems that $x=0$ is a repelling fixed point with no convergence in this case.  What would be the best way to explain these results mathematically? At what time will the upcoming Ubuntu release be made available? Prove that $A^*A + I$ is invertible Let $A$ be an $m\times n$ matrix. Prove that $A^*A + I$ is invertible.   I'm not sure what to do because everything I try ends up at $A^*A$ again and not $AA^*$. Allow a user to download a file after submitting their email address Environment variable substitution in sed If I run these commands from a script:  #my.sh PWD=bla sed 's/xxx/'$PWD'/' ... $ ./my.sh xxx bla   it is fine.  But, if I run:  #my.sh sed 's/xxx/'$PWD'/' ... $ ./my.sh $ sed: -e expression #1, char 8: Unknown option to `s'    I read in tutorials that to substitute environment variables from shell you need to stop, and 'out quote' the $varname part so that it is not substituted directly, which is what I did, and which works only if the variable is defined immediately before.  How can I get sed to recognize a $var as an environment variable as it is defined in the shell?