Get data as a list against a primary key in from the database
How to use GROUP BY to concatenate strings in MySQL?
From Geneva airport to Lausanne station Batch renaming files with pattern I have some files named like these:  63018933.mp4?token=1325697436_b0c3e70c6e339380b4a484c576a8c287  63808488.mp4?token=1325697401_4ae5f7a68d93873c8881b303e7655e14  How do I rename all them to, for example 63018933.mp4(remove characters after mp4)? Ubuntu 20.04 Failed to Set MokListRT: Invalid Parameter I have a MacBook Pro and only use Ubuntu on it. I just upgraded from 18.04 to 20.04. Now when I start the computer it says: Failed to Set MokListRT: Invalid Parameter Could not create mokListRT: Invalid Parameter Importing MOK states has failed: import_mok_state() failed: Invalid Parameter Continuing boot since secure mode is disabled.  Does anyone know EXACTLY how I can fix this?? Step-by-step process I don't want to mess anything up trying to fix this. AuraClientService.postProcess: error in processing [RangeError: Maximum call stack size exceeded] - Client Side Action I have a lightning component that is using ui:inputSelect.   The component code:              &lt;div class="slds-form-element__control"&gt;                 &lt;ui:inputSelect class="slds-select" aura:id="quals" change="{!c.getPreCodes}"&gt;                     &lt;aura:iteration items="{!v.questions}" var="q"&gt;                          &lt;ui:inputSelectOption aura:id="question" text="{!q.Id}" label="{!q.Question_Text__c}"/&gt;                     &lt;/aura:iteration&gt;                 &lt;/ui:inputSelect&gt;             &lt;/div&gt;   The controller:      getPreCodes : function(cmp, event, helper){         var selected = cmp.find("quals").get("v.value");          var action = cmp.get("c.getPreCodes");         action.setParams({             "qualID" : selected         });         action.setCallback(this, function(response){             var state = response.getState();             if (state === "SUCCESS") {                  console.log('precodes: ', response.getReturnValue());              }         });          $A.enqueueAction(action);     }   The basic logic is that the uiSelect is dynamically populated on init (this works fine). When a user makes a selection the "change" parameter function is fired to retrieve a list from the database and pass it to another component.   However, the change function {!c.getPreCodes} seems to be called recursively causing a      "Something has gone wrong. AuraClientService.postProcess: error in   processing [RangeError: Maximum call stack size exceeded] . Please try   again."   error. If I comment out the enqueueAction the function only runs once (nothing is called recursively) so I suspect it has something to do with the controller call. Best technique to create oldschool (fake 3D) racing game? What would be a good approach to develop the render system for an oldschool type racing game that uses a pseudo 3D scenery, like for example Outrun or Lotus Esprit Turbo Challenge? There's an endless scrolling road and scenery graphics are placed like billboard items, etc. I think you get the idea.    Are these developed in a similar way like  or is there a different technique behind it? Does the technique has a specific name I could search for on the web? I need to develop something like that in Flash. options for appearance of links in hyperref My keyboard doesn't have an Fn key so I can't get the coordinates to show up. I don't know how to get into the multiplayer settings and Shift + F3 doesn't work either.  How can I fix this? What does 'close invalidated' mean Recently I flagged  as a duplicate. A few days later, when I checked it again to see if it was closed, I realized it wasn't.    Searching in Meta brought me to , where a comment suggested checking the timeline. So I checked the  and saw that the close flag was set as invalidated.  Does this mean that it was disputed? When I click on it I see only "This item is no longer reviewable." Do I need more reputation (3000+ ?) to view more detailed information? Testing random number generation I have a program which generates random numbers. How can I test if the random number generator is generating actual random numbers? I'm unable to access the following website from my Internet Explorer 8 under Windows XP with Internet Explorer unable to display web page error. By the other hand the FireFox browser at the same Windows XP can access this website.  How to solve the issue with IE8 ? Draw power from a portable mobile charger to power circuits Why does $\lim\limits_{t\to-\infty}te^t=0$? Intuitively, $\lim\limits_{t\to -\infty}te^t=0$, since $e^t\to 0$ much faster than $t\to -\infty$.   Is there a way to more rigorously compute this? Writing it as $e^t/(1/t)$ seems resistant to l'Hopital's rule. $\lim_{n\to\infty}((\frac94)^n+(1+\frac1n)^{n^2})^{\frac1n}$  Here's what I did:  $\lim_{n\to\infty}((\frac94)^n+(1+\frac1n)^{n^2})^{\frac1n}\\ =(\lim(\frac94)^n+\lim((1+\frac1n)^{n})^n)^{\frac1n}\\ =(\lim(\frac94)^n+\lim e^n)^{\frac1n}\\$  Any hints on how to continue?  PS: no logs/integration/derivation because we haven't covered it. I have a simple spreadsheet, two columns "Amount" (col Q) and "Account" (col O).  I want to get the sum of the "Amount" column where the corresponding "Account" forum equals "Paypal".  This is as far as I can get!  =SUM(Q:Q)*(O:O="Paypal") I'm using an HP laptop running Windows 7 Home Edition.  The moment I reach the login screen the computer automatically types "ppppppppp" in the password place, luckily I have fingerprint login to counter that.  The moment I login, it keeps acting as if I'm typing 'p' repeatedly. I tried removing the button and cleaning under it but it was no use. I've tried restarting, uninstalling the keyboard driver, but it was no use.  I can't go to Control Panel because the moment I get there, it starts typing "pppppp" in the search field and I'm unable to find anything.  I'm typing this from my phone because going anywhere on my laptop seems impossible. Find the sum of angles without trigonometry? Conveying "under the radar" in a less colloquial way In my experimentation, I've used only BJTs as switches (for turning on and off things like LEDs and such) for my MCU outputs. I've been repeatedly told, however, that N-channel enhancement-mode MOSFETs are a better choice for switches (see  and , for examples), but I'm not sure I understand why. I do know that a MOSFET wastes no current on the gate, where a BJT's base does, but this is not an issue for me, as I'm not running on batteries. A MOSFET also requires no resistor in series with the gate, but generally DOES require a pull-down resistor so the gate doesn't float when the MCU is rebooted (right?). No reduction in parts count, then. There doesn't seem to be a great surplus of logic-level MOSFETs that can switch the current that cheap BJTs can (~600-800mA for a 2N2222, for example), and the ones that do exist (TN0702, for example) are hard to find and significantly more expensive. When is a MOSFET more appropriate than a BJT? Why am I continually being told that I should be using MOSFETs? When you die, 3 things happen.    You swear  A message appears in the chat log describing how you died A "You died" screen appears, with the options to quit or respawn, and a "Score".   What contributes to this score? How can I transfer large files from Linux to iPad over a cable or wifi? I am looking for a way to transfer large files to the iPad without using iTunes or pushing to and pulling from a remote server.  I run an Ubuntu laptop as my only OS at the moment and want to be able to transfer movies to my iPad.  I currently transfer most of my files by way of the dropbox app which works well for small files but is quite slow for larger files and eats up my bandwidth.  Ideally I'd like to be able to transfer over a cable or through WiFi.  Thanks for any tips.