I would like to do an neat scheme of my database to pin down ideas, particularly I would like to do something like in the attached picture. Even though I have looked in internet thoroughly, I have not been able to find something similar that serves me as template in latex.  Any help, specially that regarding templates, tutorials and manuals in order of importance, would be much appreciated.  KR
I found  post about how to do Crow's Foot ERM Diagrams with Tikz, but it looks strange because the entity is outside the frame. However, it worked.  Then I found  even nicer version and tried to combine it, but sadly I'm not able to find out why it doesn't work. I'm not able to print two entities side by side and connect them with a crow's foot wire. They always print over each other...  How can I have both the lines and the style?  \documentclass{article}  \usepackage{tikz} \usetikzlibrary{shapes.multipart} \usetikzlibrary{matrix} \usetikzlibrary{positioning} \usetikzlibrary{shadows} \usetikzlibrary{calc}  \tikzset{     entity/.code={         \tikzset{             rounded corners,                          name=#1,             inner sep=2pt,             every entity/.try,         }%         \def\entityname{#1}%     },     entity anchor/.style={matrix anchor=#1},     every entity/.style={             draw,     },     every property/.style={         inner xsep=0.20cm, inner ysep=0.075cm, anchor=west, text width=1.75in     } } \def\property#1{\node[name=\entityname-#1, every property/.try]{\propertysplit#1;};} \def\properties{\begingroup\catcode`\_=11\relax\processproperties} \def\processproperties#1{\endgroup%     \gdef\propertycode{}%     \foreach \p in {#1}{%     \expandafter\expandafter\expandafter\gdef\expandafter\expandafter\expandafter\propertycode%             \expandafter\expandafter\expandafter{\expandafter\propertycode\expandafter\property\expandafter{\p}\\}%     }%     \propertycode% } \def\propertysplit#1:#2;{#1:\hfill#2}  \def\entitynamenode{% \node[every entity name/.try] (\entityname-name) {\entityname}; \draw (\entityname-name.south west) -- (\entityname-name.south east); \\[1ex] } \tikzset{   every entity name/.style={every property/.try, align=center} } \begin{document} \begin{tikzpicture}[every node/.style={font=\ttfamily}, node distance=0.5in] \matrix (m1) [entity=Employee] {     \entitynamenode     \properties{         Username:,         Password :  varchar(255),                 Name :  varchar(255),         LastName :  varchar(255)     } }; \matrix (m2) [entity=Student] {     \entitynamenode     \properties{         Username:,         Password :  varchar(255),                 Name :  varchar(255),         LastName :  varchar(255)     } }; \draw [-&gt;] (m1) -- (m2); % &lt;-- it break's here... %\draw [one to omany] (Employee-Username:) to node[above]{label} (Student-Username:); \end{tikzpicture} \end{document}      Edit: this is a Crow's Foot Notation for visualizing IT Database structures:
To find out how something is called is the one thing I don't know how to use Google for.  If I have a vector $v$ and a symmetric matrix $H$, then the operation $v^T H v$ gives me some sort of projection of the matrix $H$ on the vector $v$. For example if $H$ is the Hessian, the operation gives me the second derivative in the direction of $v$.  What is the name of this operation? Can a Sorcerer protect their friend from Web by using Careful Spell? With the metamagic "Careful Spell" does the caster protect his friend from a Web spell for its full duration or just for the first save? If the friend stays in the area or re-enters the area does he continue to automatically save against the restraining effect? Understanding d-separation theory in causal Bayesian networks I am trying to understand the d-Separation logic in Causal Bayesian Networks. I know how the algorithm works, but I don't exactly understand why the "flow of information" works as stated in the algorithm.    For example in the graph above, lets think that we are only given X and no other variable has been observed. Then according to the rules of d-separation, the information flow from X to D:   X influences A, which is $P(A)\neq P(A|X)$. This is OK, since A causes X and if we know about the effect X, this affects our belief about the cause A. Information flows. X influences B,which is $P(B)\neq P(B|X)$. This is OK, since A has been changed by our knowledge about X, the change at A can influence our beliefs about its cause, B, as well. X influences C,which is $P(C)\neq P(C|X)$. This is OK because we know that B is biased by our knowledge about its indirect effect, X, and since B is biased by X, this will influence B's all direct and indirect effects. C is a direct effect of B and it is influenced by our knowledge about X.   Well, up to this point, everything is OK for me since the flow of the information occurs according to intuitive cause-effect relationships. But I don't get the special behavior of so called "V-structures" or "Colliders" in this scheme. According to the d-Separation theory, B and D are the common causes of C in the graph above and it says that if we did not observe C or any of its descendants, the flow information from X is blocked at C. Well, OK, but my question is why?  From the three steps above, started from X, we saw that C is influenced by our knowledge about X and the information flow occurred according to the cause-effect relationship. The d-Separation theory says that we cannot go from C to D since C is not observed. But I think that since we know that C is biased and D is a cause of C, D should be affected as well while the theory says the opposite. I am clearly missing something in my thinking pattern but can't see what it is.  So I need an explanation of why the flow of information blocked at C, if C is not observed. How widely-accepted is "What do you got?" to Americans? Watching , I noticed that Melanie Griffith twice asked    I recognise this as an American construction which sounds strange to me — Brits invariably say either "What have you got?" or "What do you have?". But I'd be interested to know if it's considered "normal" by most/all Americans, or if it's regionally or otherwise restricted. What bends fabric of space-time? I know that mass can bend fabric of space-time, which causes gravity by making an object curve around a planet or star but is there anything else that can bend it?  Other energy sources, forces anything? Expression for a choice which isn't really one Include ALL pdf graphics in document I have several plots saved as .pdf in a folder and I would like to know if there is a way of adding all of them in a document at once, without typing the path to each file. How do I choose between "while" and "whilst"? When should whilst be used instead of while?  For example, should I use the first or the second sentence?      They don't do this whilst they do that.   They don't do this while they do that.   Which would be correct? Category of profinite groups Is there any way to prevent mc from taking 10-30 seconds to open? Say a prospective PhD has a high reply rate (90-95%) to first contact emails with potential superviors. He/She has a well thought out e-mail, but a particular professor (here: USA) that is in the top preferences does not reply after two to three e-mails that were sent within a time frame of three months. I also followed the instructions on the professor personal website in the section "prospective PhD students". The student has already contacted some of the advisor students and has received positive feedback about the professor.  Should the student just give up and move on? Should the student keep trying?  Aside from the obvious "I have too many incoming e-mails to answer" or "I am out in the field", what could create a no response behavior from the professor?  I have seen the simplistic answer "move on, bad advisor, doesn't have time, etc". But this seems a contradiction in this case. The PhD students like the professor and say he/she is personable and no e-mail response after a few well written emails. Are the review queues planned for the iOS app? if $(x_0,y_0)$ is local extrema in $ax^2 + by^2 + cxy + dx + ey + l$ then its global too. An exercise on a book asks me to prove that if a point $(x_0,y_0)$ is a local extrema for the function $$f(x,y) = ax^2 + by^2 + cxy + dx + ey + l$$ then it's also a global extrema.  The exercise asks me to consider that $g(t) = f(x_0+ht,y_0+kt)$ is a parabola, but I couldn't understand how it helps. Maybe since it's a parabola, I know that this derivative has to be $0$ in some point, and also that this function $g(t)$ has a global extrema point, but I couldn't derive anything from this. I also tried to find the derivatives, equal them to $0$ and solve the system. I got:  $$x_0 = -\frac{2 b d - c e}{4 a b - c^2}, y_0 = -\frac{   c d - 2 a e}{-4 a b + c^2}$$  But when I try to find   $$f\left(-\frac{2 b d - c e}{4 a b - c^2},-\frac{   c d - 2 a e}{-4 a b + c^2}\right)$$ so I can try to prove:  $$f(x,y)-f(x_0,y_0)$$  is either greater or less $0$ depending on the case (so I can do $f(x,y) \le f(x_0,y_0)$ and $f(x,y) \ge f(x_0,y_0)$)  things get hairy. $r$ primitive root of prime $p$, where $p \equiv 1 \mod 4$: prove $-r$ is also a primitive root question is as follows:  Let $p$ be a prime with $p \equiv  1 \mod 4$, and $r$ be a primitive root of $p$.  Prove that $-r$ is also a primitive root of $p$.  I have shown that $-r^{\phi(p)} \equiv 1 \mod p$.  What I am having trouble showing, however, is that the order of $-r$ modulo $p$ is not some number (dividing $\phi(p)$ that is LESS than ($\phi(p)$).  By way of contradiction, I've shown that the order of $-r$ cannot be an EVEN number less than $\phi(p)$.  But my methodology does not work for the hypothetical possibility of an ODD order that is less than $\phi(p)$.  Any and all help appreciated.  Happy to show methodology for any of the parts I have managed to do, if requested. Let's say there is a user who has found a satisfactory answer to a common question asked on Stack Overflow (or other Stack Exchange website).  This answer may be a snippet of code, or an addon, or a framework, or something else.    Is it acceptable for this user to formulate an answer for one question, find every related question and then copy the exact answer to each of those questions?  And, if not, what should  users who finds themselves in this situation do? Is there a mass spectrometer software that can measure the mass of a proton Let $A$ be a commutative ring, $I$ an ideal of $A$ and $M$ an module over $A$. Is it true that $\operatorname{Ann}(M/IM) = \operatorname{Ann}(M) + I$?    One inclusion is certainly true, but I don't know about the other one. If the above statement does not hold in general, does it perhaps for finitely generated modules? Path bar missing in file dialog after running software updater for Ubuntu 17.04 After running software updater, the path bar in the file dialog (for example the one you get when choosing Open File in in Google Chrome or Firefox) is missing. This is frustrating since it's no longer possible to copy a path from the terminal (for example) and paste it into the file dialog. Here is a screenshot of the dialog:     How can I get back the path bar? I am asked to solve $$u_x+u_y=1$$ If is was homogeneous i.e., $u_x+u_y$ the answer would be $u(x,y)=f(y-x)$ where $f$ is an arbitrary function. I have found the following set of solutions: $$u(x,y)=\lambda x +(1-\lambda)y$$ where $\lambda$ is an arbitrary constant(real or imaginary). I just have no idea what method other then trial and error would have lead me here. Any ideas? Thanks! Can I use a card with "Add one mana of any color to your mana pool" in any Elder Dragon Highlander (EDH) deck? I recently tried /, and found it to be a ton of fun.  I've started customizing one of the pre-cons I got, but I'm a little confused by some of the deck-building requirements.  According to the deck-building rules:   A card's color identity is its color plus the color of any mana symbols in the card's rules text. A card's color identity is established before the game begins, and cannot be changed by game effects. Cards in a deck may not have any colors in their identity which are not shared with the commander of the deck. (The identity of each card in the deck must be a subset of the General's)    If I'm using  as my general, my deck's identity is Red, Blue and Green.  I couldn't use  in my deck, because it has a black mana symbol in the rules text.  My question is:  can I add a card to my deck that has the phrase "Add one mana of any color to your mana pool" (such as  or )?  Even though those cards could conceivably add black mana to my mana pool, they don't have a black or white (or any for that matter) mana symbol in their rules text, so they would be valid for inclusion in any deck?