mysql_real_escape_string() function for $user In PhP script, swears demanding to do how to fix it? In this part requires to replace it:      $sql = "SELECT * FROM wallets WHERE id = '$user' LIMIT 1";   Requires to do this: use the mysql_real_escape_string() function for the $user parameter  How to implement it?  $sql = "SELECT * FROM wallets WHERE id = '$user' LIMIT 1";   Eliminate vulnerability!
How can I prevent SQL injection in PHP? If user input is inserted without modification into an SQL query, then the application becomes vulnerable to , like in the following example:  $unsafe_variable = $_POST['user_input'];   mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')");   That's because the user can input something like value'); DROP TABLE table;--, and the query becomes:  INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')   What can be done to prevent this from happening?
How to find a whole word in a String in java Issues with win key and right alt key after Windows Update (Polish diacritical signs not working) I have this input:  sdkxyosl 1 safkls 2 asdf--asdfasxy_asd 5 dkd8k  jasd 29 sdi44sw 43 asasd afsdfs 10 rklyasd 4   I need this output:  sdi44sw 43 dkd8k  jasd 29 asasd afsdfs 10 asdf--asdfasxy_asd 5 rklyasd 4 safkls 2 sdkxyosl 1   So i need to sort the lines by the last column.  I don't know how many columns are in one line.  I just can't figure it out, how to do it. I don't have "perl powers". I just have ~average scripting powers with sed, awk, cut, etc..   Does somebody know how to do it? Using "that" and "this" interchangeably $x^p-c$ has no root in a field $F$ if and only if $x^p-c$ is irreducible? Hungerford's book of algebra has exercise $6$ chapter $3$ section $6$ [Probably impossible with the tools at hand.]:     Let $p \in \mathbb{Z}$ be a prime; let $F$ be a field  and let $c \in  F$. Then $x^p - c$ is irreducible in $F[x]$ if and only if $x^p - c$   has no root  in $F$. [Hint: consider two cases: char$(F) = p$ and   char$(F)$ different of $p$.]   I have attempted this a lot. Anyone has an answer? Cauchy-Schwarz inequality proof (but not the usual one) Before you downvote/vote-to-close, I am not asking for a proof of: $$\sum^n_{i=1}a_ib_i\le\sqrt{\sum_{i=1}^na_i^2}\sqrt{\sum^n_{i=1}b_i^2 } $$ Which is what EVERY link I've found assumes is the inequality (for a proof of that see:  )    I am reading a book that claims the Cauchy-Schwarz inequality is actually: $$\vert\langle x,y\rangle\vert\le\Vert x\Vert\Vert y\Vert$$ where $\Vert x\Vert :=\sqrt{\langle x,x\rangle}$  with the additional claim: equality holds $\iff\ x,y$ are linearly dependent  I cannot find a proof of this claim (only proofs for the dot product inner product). My question is: what is the simplest way to prove this (I define simplest to mean "using as few definitions outside of the inner product itself as possible" - so that's not including Gramm-Schmitt orthonormalisation, for example.)  I've just found some possible answers in the links on the right (annoyingly) but fortunately I have a second, albeit softer, question:  What inequalities that are common for say $\mathbb{R}^n$ are actually based on the inner product?   (In future I will check this site first, I was targeting lecture notes and such in my search)  Addendum: I want to use this on not-finite dimensional vector spaces. I've found one proof that relies on finite-ness. Possible orders of permutations of $11$ symbols How can I assign custom icons to folders? Prove universal morphism is unique up to unique isomorphism. How to count the number of occurrences of each item in an array? mysql database no space available I was restoring a 200 GB database into a newly installed RHEL machine. However, while restoring I ran into no space available issue.   Is it possible to change the directory where the databases are stored? How can I convert String to Int? Do's and Don't's of Undergraduate Research I was fortunate enough to get a position as a researcher for the Mayo Clinic's SURF Program this year. My PI's lab focus is on the the immune system's role in CNS axonal and neuronal injury, specifically through the lens of how innate and adaptive immune effectors interact w/ infected neurons.  Although I do research under a professor at my college and I volunteered for a state university lab during the previous summer, this is my first REU/SURF opportunity, and I REALLY want to make a good impression. Here are my questions:  What are the do's and don't's in terms of being a skilled and efficient researcher?  Since I am still an undergrad, I know that I will be a less useful asset to the lab than a grad student or post-doc, but what can I do as an undergrad to not burden my colleagues and PI?  Thank you all for your help! Wishing you all the very best! Difference between shadowing and overriding in C#? What's difference between shadowing and overriding a method in C#? Should the downvoters/upvoters have enough reputations on all the tags of the question/answers? Is it posible to change the locale of my device? Variation of the Kempner series – convergence of series $\sum\frac{1}{n}$ where $9$ is not a digit of $1/n$. It is easy to argue that the  converges:  $$  \sum\limits_{\substack{n \text{ s.t. 9 is}\\\text{ not a digit} \\\text{ of } n}}  \frac{1}{n} &lt; \infty$$  Let $E \subset \Bbb N_{&gt;0}$  the subset of the positive integers  such that $9$ is not a digit of the decimal expansion of $1/n$ (the decimal expansion is not allowed to have a trailing infinite sequence of "$9$"s. For instance $0.24999...$ is not allowed).  Here are the  that don't belong to $E$ : $11,13,17,19,21,23,29,31,34,38,41,…$ (not known by the OEIS, by the way).  My question is:     Does the series    $$ \sum\limits_{n \in E} \frac{1}{n} \tag 1$$ converge?   My attempt is :   Let $1/n = 0,a_1 a_2 \dots a_k \overline{b_1 b_2 \dots b_m}$ with $n \in E$. Since $1/n$ has no digit "9", we have at most $9^{k+m}$ possibilities for the $a_i$'s and $b_j$'s. Moreover, $1/n ≥ 0,00...0\overline{00...01}≥1/10^{k+m}$. But then I can only bound my series $(1)$ from below, by some real number. So, this is not a clue for the divergence of the series. Apparently, the numbers of the form $n=10k+1$ don't belong to $E$. Maybe we can find sufficiently many numbers that have $9$ in the decimal representation of their reciprocals, so that $(1)$ could converge...   Any comment will be appreciated ! I'd like some suggestions for good reading materials on the Keldysh formalism in the condensed matter physics community. I'm familiar with the imaginary time, coherent state, and path integral formalisms, but lately, I've been seeing Keldysh more and more in papers. My understanding is that it is superior to the imaginary time formalism at least in that one can evaluate non-equilibrium expectations. This is a  about Hairpin NAT (Loopback NAT).   The generic form of this question is:  We have a network with clients, a server, and a NAT Router. There is port forwarding on the router to the server so some of it's services are available externally. We have DNS pointing to the external IP. Local network clients fail to connect, but external work.   Why does this fail? How can I create a unified naming scheme (DNS names which work both locally and externally)?   This question has answeres merged from multiple other questions. They originally referenced FreeBSD, D-Link, Microtik, and other equipment. They're all trying to solve the same problem however. Is there a way to find self-answers with the advanced search? Preferably, not using the  and including results of all time and not just the recent ones with the new share your knowledge, Q&amp;A-style