oracle group by can't get last payment_date, payment_sum
ORA-00979 not a group by expression
High-end compact camera with swivel screen and running on AA batteries I'm looking for a new compact camera that:   has a  is small enough to be mountable on a  and, runs on AA batteries. good flexibility   Requirement (3) stems from the fact that I may be hiking in the wild for weeks on an end, with no opportunity to change a Lithium-Ion battery. If another solution permits me to take thousands rather than hundreds photographs on full charge, I may consider that as well.  Additionally, it would be nice (but not essential) to have:   the ability to handle high dynamic range a viewfinder physical buttons — I live in a cold climate, and don't like to use touch-screens   The upper price range for compact models is still good for me, and I don't mind a pricerange of €400–€800 (but I don't mind cheaper either, if still of good quality).  I've been the happy user of several models in the , but now my PowerShot A650 IS has died. Starting from , it seems requirement (3) kills of many cameras: the , (might also fail (2)), the , the , the ... Although enough models meet requirements (1), (2), and (4), as well as the (non-essential) additional features I listed, it seems in the past 5 years, cameras have moved away from using AA batteries. What camera models still exist that meet my requirements?    Last photograph taken with my Canon PowerShot A650 IS, taking on Christmas Day 2012 in the Caldera de Taburiente, La Palma, Canary Islands, Spain. How to fix a stripped pedal crank The threads on my bike's pedal crank just became fully stripped and the pedal fell off, though the pedal itself is fine. Is there any way I can fix this without fully replacing the pedal crank? Assume you are given two objects whose exact locations are unknown, but are distributed according to normal distributions with known parameters (e.g. $a \sim N(m, s)$ and $b \sim N(v, t))$. We can assume these are both bivariate normals, such that the positions are described by a distribution over $(x,y)$ coordinates (i.e. $m$ and $v$ are vectors containing the expected $(x,y)$ coordinates for $a$ and $b$ respectively). We will also assume the objects are independent.  Does anyone know if the distribution of the squared Euclidean distance between these two objects is a known parametric distribution? Or how to derive the PDF / CDF for this function analytically? How can Cooper communicate with his daughter before the time he went to space? In the movie Interstellar it's shown that after Cooper fell into the Black Hole, he communicates with his daughter Murph through some codes as Ghost. My doubt is how can he communicate to his daughter before he goes into space? I didn’t get the logic of that part. Can anyone please make it clear? What is the meaning of the third derivative of a function at a point How come the year doesn't show here? Transit Visa in Hong Kong for 15 hour layover between India and USA? We are (2) Indian nation and travelling from India to USA via Hong Kong airport and about 15 hours layover in Hong Kong airport. Do we need a transit visa even if only changing planes? And can we apply in Hong Kong Airport? Roots of polynomials in field of prime characteristic p Let $F$ be a field of characteristic $p$, and let $\alpha \in F$. Let $f \in \mathbb{Z}_p[x]$ be such that $f(\alpha) = 0$. Apparently, we have $f(\alpha^p) = 0$. This was mentioned but not proved in my lectures. Can someone explain why please?  Thanks. Finding parenthesis via regular expression If $f: \Bbb{R}\rightarrow\Bbb{R}$ is continuous at $0$ and $f(x)=f(2x)$ for each $x\in\Bbb{R}$ then $f$ is constant. How do I prove that if $f: \Bbb{R}\rightarrow\Bbb{R}$  is continuous at $0$ and $$f(x)=f(2x)$$ for each $x\in\Bbb{R}$, then $f$ is constant? How can I determine whether a conference is reputable? I recently received an invitation to a conference and I'm trying to determine how reputable it is. Is there a good way to go about this? 'setenv' command not working on tcsh shell when called explicitly I can run setenv command just fine in my tcsh shell like this:  echo $0 /usr/bin/tcsh echo $SHELL /usr/bin/tcsh setenv START_TIME `date +%s` echo $START_TIME 1499355967   But, whenever I run it explicitly like shown below, it doesn't work. I need to do this because I have to specify shell when executing it via python subprocess call, otherwise it will call a sh shell as default.  /usr/bin/tcsh -i -f -c 'setenv START_TIME `date +%s`' echo $START_TIME START_TIME: Undefined variable.   What's the problem here? I searched for this issue online, but couldn't find any issue similar to this. This is extremely frustrating. I am wondering how to show that $\mathbb{Z}[\sqrt {10}]$ is not a UFD.    My only idea is to show that there are two factorizations of $10$, say, $ab, uv$ such that $a$ is not a unit times $u$ or $v$. In this ring $10=2\cdot5=\sqrt {10}\cdot \sqrt {10}$, so it suffices to show $2$ is not a unit times $\sqrt {10}$. Suppose $2=\sqrt {10}(a+b\sqrt{10})=a\sqrt{10}+10b$. Then $a=0$ since $\sqrt{10}$ is not rational. So $10b=2$, which has no integer solutions. So $\mathbb{Z}[\sqrt {10}]$ is not a UFD.  Is my reasoning correct? What are the flaws? Get output parameter value in ADO.NET Definition of the $Q$ factor? According to Wikipedia, the  is defined as:  $$Q=2\pi\frac{\mathrm{energy \, \, stored}}{\mathrm{energy \, \,dissipated \, \, per \, \, cycle}}.$$  Here are my questions:   Does the energy dissipated per cycle assume that the amplitude is constant from one cycle to the next. Is it always calculated at the resonance frequency? If the answer to 2 is yes can you explain why for a forced oscillator system with a damping coefficient of $\gamma$ and natural frequency $\omega_o$ the quality factor is $Q=\omega_o/\gamma$ and not some more complicated expression involving the actual resonant frequency (which is not quite $\omega_o$  and is given by $$\omega_r=(\omega_0^2-\frac{\gamma^2}{2})^{\frac{1}{2}}$$ of the system? Is this just an approximation i.e. are we assuming that it resonates at $\omega_o$ but in fact the actual expression is a big more complicated?   Edit: With using the actual value of $\omega_r$ I get: $Q=(\omega_0^2-\frac{\gamma^2}{2})^{\frac{1}{2}}/\gamma$  is this more correct? Is there a higher register word that means to criticize something highly specific and inconsequential? Any synonym I can think of seems a little too vernacular, e.g. "to split hairs", "to nitpick". What's a more professional/academic way of saying this? I'd prefer a single word if one exists. How can a singularity in a black hole rotate if it's just a point? I guess nobody really knows the true nature of black holes, however, based on everything I know about black holes, there is a "singularity" at their center, which has finite mass but is infinitely small and thus infinitely dense.  So a black hole is really just a point mass that dramatically warps the space-time around it so that an event horizon is achieved.  What doesn't make sense to me is how a true mathematical "point" can rotate, or at least how it is even possible to determine if a point is rotating (or if it should even make a difference about whether or not it is rotating, for the same reason it would be impossible to tell if a perfect, featureless sphere were rotating (I know it would have higher rotational energy but lets assume you can't measure that because a true "point" can't attain rotational energy since it has no radius)).  The only conceptual solution I have to describe a rotating black hole would be to compare it to a rotating whirlpool, where the surface of the water is the fabric of space-time... but this is different because there is no "singularity" in a whirlpool that causes the water around it to rotate, whirlpools form from flow of water around a point (put into motion perhaps by some kid swirling water in a 2-liter bottle... it's due to an external cause), but the only thing that could cause rotation around a black hole would be the singularity itself, which doesn't make sense because, once again, how can we know if a true point is actually rotating?  Aside from everything I've said, here is what I am actually asking:  Why/how do some black holes rotate... what is the mechanism of their rotation (is analogous to a spinning point or a 3-d whirlpool, or something different)? Why is SQL Server losing a millisecond? I have a table structured like this:  CREATE TABLE [TESTTABLE] (     [ID] [int] IDENTITY(1,1) NOT NULL,     [DateField] [datetime] NULL,     [StringField] [varchar](50),     [IntField] [int] NULL,     [BitField] [bit] NULL )   I execute the following code:  BEGIN     INSERT INTO TESTTABLE (IntField, BitField, StringField, DateField)     VALUES ('1', 1, 'hello', {ts '2009-04-03 15:41:27.378'});       SELECT SCOPE_IDENTITY()   END   And then   select * from testtable with (NOLOCK)   and my result shows:  2009-04-03 15:41:27.*377*   for the DateField column.  Any ideas why I seem to be losing a millisecond?? Ball $X^*$ is weak-star metrizable iff X is separable in Conway's book. This is a Theorem in Conway's book     I don't understand in the third paragraph why there are open sets $\{U_n:n\geq1\}$ in $(ball X^*,wk^*)$ such that $0\in U_n$ and $\bigcap^{\infty}_{n=1}U_n=\{0\}$. By the definition of the relative weak-star topology on ball $X^*$, for each $n$, there exists a finite set $F_n$ contained in $X$ such that $$\{x^*\in\text{ball }X^*:|\langle x,x^*\rangle|&lt;1 \text{ for all }x\in F_n\}\subseteq U_n.$$  Can someone explain this for me？ Thank you so much!! How to avoid pagenumering with text in scrlttr2 Have a Letter in scrlttr2. I cannot avoid/exclude the text before the page number 'Seite' (see print-screen). The  recommends to add \pagenumbering{arabic}. But for my document, it has no effect.    %--------------------------------------------------------------------------- \documentclass%% %---------------------------------------------------------------------------   [fontsize=12pt,%%          Schriftgroesse %--------------------------------------------------------------------------- % Satzspiegel    paper=a4,%%               Papierformat    enlargefirstpage=on,%%    Erste Seite anders    pagenumber=footcenter,%%   Seitenzahl oben mittig %--------------------------------------------------------------------------- % Layout    headsepline=on,%%         Linie unter der Seitenzahl    parskip=half,%%           Abstand zwischen Absaetzen %--------------------------------------------------------------------------- % Formatierung    draft=on%%                Entwurfsmodus ]{scrlttr2} %--------------------------------------------------------------------------- \usepackage{german} \usepackage[T1]{fontenc} \usepackage[utf8]{inputenc}  %--------------------------------------------------------------------------- \begin{document} %--------------------------------------------------------------------------- % Briefstil und Position des Briefkopfs \LoadLetterOption{DIN} %% oder: DINmtext, SN, SNleft, KOMAold. \makeatletter \pagenumbering{arabic}  %--------------------------------------------------------------------------- % Seitenstil \pagestyle{plain}%% keine Header in der Kopfzeile %--------------------------------------------------------------------------- \begin{letter}{Herr\\                 Mustermann\\                Straße 1\\                12345 Stadt} %--------------------------------------------------------------------------- \setkomavar{subject}{Beispielschreiben} %--------------------------------------------------------------------------- \opening{Liebe Herr Mustermann,}  here is some Text.  \pagebreak  here is some Text. %--------------------------------------------------------------------------- \end{letter} %--------------------------------------------------------------------------- \end{document} %---------------------------------------------------------------------------