Search Results

Search found 30398 results on 1216 pages for 'embedded sql'.

Page 510/1216 | < Previous Page | 506 507 508 509 510 511 512 513 514 515 516 517  | Next Page >

  • Design Practice Retrieve Multiple Users - PHP

    - by pws5068
    Greetings all, I'm looking for a more efficient way to grab multiple users without too much code redundancy. I have a Users class, (here's a highly condensed representation) Class Users { function __construct() { ... ... } private static function getNew($id) { // This is all only example code $sql = "SELECT * FROM Users WHERE User_ID=?"; $user = new User(); $user->setID($id); .... return $user; } public static function getNewestUsers($count) { $sql = "SELECT * FROM Users ORDER BY Join_Date LIMIT ?"; $users = array(); // Prepared Statement Data Here while($stmt->fetch()) { $users[] = Users::getNew($id); ... } return $users; } // These have more sanity/security checks, demonstration only. function setID($id) { $this->id = $id; } function setName($name) { $this->name = $name; } ... } So clearly calling getNew() in a loop is inefficient, because it makes $count number of calls to the database each time. I would much rather select all users in a single SQL statement. The problem is that I have probably a dozen or so methods for getting arrays of users, so all of these would now need to know the names of the database columns which is repeating a lot of structure that could always change later. What are some other ways that I could approach this problem? My goals include efficiency, flexibility, scalability, and good design practice.

    Read the article

  • ARM cortex: mutex using bit banding

    - by Jeff V
    Given that, on the ARM Cortex M3, I can: atomically read a single bit atomically set a single bit atomically clear a single bit How can I combine these for a mutex style set of operations: try lock take lock release lock It seems that try_lock or take_lock would require two operations that would not be atomic. Do I need more control to accomplish this? Disable global interrupts would do it but it seems there should be a more surgical approach.

    Read the article

  • Troubleshooting failover cluster problem in W2K8 / SQL05

    - by paulland
    I have an active/passive W2K8 (64) cluster pair, running SQL05 Standard. Shared storage is on a HP EVA SAN (FC). I recently expanded the filesystem on the active node for a database, adding a drive designation. The shared storage drives are designated as F:, I:, J:, L: and X:, with SQL filesystems on the first 4 and X: used for a backup destination. Last night, as part of a validation process (the passive node had been offline for maintenance), I moved the SQL instance to the other cluster node. The database in question immediately moved to Suspect status. Review of the system logs showed that the database would not load because the file "K:\SQLDATA\whatever.ndf" could not be found. (Note that we do not have a K: drive designation.) A review of the J: storage drive showed zero contents -- nothing -- this is where "whatever.ndf" should have been. Hmm, I thought. Problem with the server. I'll just move SQL back to the other server and figure out what's wrong.. Still no database. Suspect. Uh-oh. "Whatever.ndf" had gone into the bit bucket. I finally decided to just restore from the backup (which had been taken immediately before the validation test), so nothing was lost but a few hours of sleep. The question: (1) Why did the passive node think the whatever.ndf files were supposed to go to drive "K:", when this drive didn't exist as a resource on the active node? (2) How can I get the cluster nodes "re-syncd" so that failover can be accomplished? I don't know that there wasn't a "K:" drive as a cluster resource at some time in the past, but I do know that this drive did not exist on the original cluster at the time of resource move.

    Read the article

  • GNU ld removes section

    - by Jonatan
    I'm writing a boot script for an ARM-Cortex M3 based device. If I compile the assembler boot script and the C application code and then combine the object files and transfer them to my device everything works. However, if I use ar to create an archive (libboot.a) and combine that archive with the C application there is a problem: I've put the boot code in a section: .section .boot, "ax" .global _start _start: .word 0x10000800 /* Initial stack pointer (FIXME!) */ .word start .word nmi_handler .word hard_fault_handler ... etc ... I've found that ld strips this from the final binary (the section "boot" is not available). This is quite natural as there is no dependency on it that ld knows about, but it causes the device to not boot correctly. So my question is: what is the best way to force this code to be included?

    Read the article

  • STM32 Compiler/Debugger Chain?

    - by Nate
    I'm starting a project with a STMicro STM32. I've done the Google searches, looking for solid compiler/debugger chains but would prefer answers with success stories. Open Source Compilers/Linkers would be ideal, I just don't know if their STM32 toolchains are stable yet. (Both C, C++ compilers are acceptable). -- So commercial options are acceptable as well. Do any of you have useful suggestions?

    Read the article

  • Flash Player - green box with version number

    - by Gavin
    I'm trying to get a very simple Flash video working using SWFembed, and it does work across multiple computers at this point in multiple browsers, but as soon as I pushed it live I got this: http://cl.ly/1EDS I've adjusted file permissions, but it is exactly the same code and files as in another directory on the server. I've seen this a few times (green box with version number), but have not been able to find any reference to it online. Thanks for any suggestions in advance!

    Read the article

  • GUI-Library for microcontroller

    - by Martin Kirsche
    I want to create a GUI driven application for a micro-controller (Atmel XMEGA) that is connected to a 128x64 dots graphics LCD (EA DOGL128-6) and 4 buttons for navigation. Controlling the display itself (e.g. drawing pixels and characters) is no problem but in order to prevent me from reinventing the wheel I was googling for a GUI-Library/-Toolkit that is written in c, includes its source code, will run on a 32 MHz 8-bit micro-controller and provides at least the following controls: panel (to group elements) menu (scrollable) icon label button line-graph (optional) But I didn't find any thing useful. Does anyone know (or better uses) such a library(preferably for free)?

    Read the article

  • Linux USB debug connection to LuminaryMicro evaluation board

    - by mikelong
    Hi, I am trying to connect a Stellaris LM3S8962 evaluation kit to a linux host machine. I am using the CodeSourcery G++ for the development toolchain. When I try to run a helloworld example the connection fails with this message: arm-stellaris-eabi-sprite: error: E104. I/O Error communicating with USB Device. arm-stellaris-eabi-sprite: waiting for GDB connection, to pass error along warning: Remote failure reply: E.fatal.E104. I/O Error communicating with USB Device. arm-stellaris-eabi-sprite: error: E002. Not initialized When I connect the evaluation board with the USB cable it seems the device is made available to the system: Mar 24 14:37:16 n6-ws2 kernel: usb 5-2: USB disconnect, address 5 Mar 24 14:37:18 n6-ws2 kernel: usb 5-2: new full speed USB device using uhci_hcd and address 6 Mar 24 14:37:19 n6-ws2 kernel: usb 5-2: configuration #1 chosen from 1 choice Also, it seems that I can connect in some way via the command line tool (but I do get some strange characters): [mlong@n6-ws2 bin]$ ./arm-stellaris-eabi-sprite -i CodeSourcery ARM Debug Sprite (Sourcery G++ 4.4-104) armusb: [speed=] ARMUSB device armusb:///?? - ?? (??) Does anyone have any suggestions I could try? Thanks a lot, Mike

    Read the article

  • AVR Analog Comparator + Internal Pullup?

    - by vicatcu
    I have what I hope is a simple question pertaining to the Atmel AVR microcontrollers. So I want to use the ATTiny85's Analog Comparator to determine if a signal is above or below a threshold. This signal is normally "floating" and grounded when "active" (i.e. it's an active low - open collector signal). If I enable the pullup on the input pin (which is also the comparator input) by doing: DDRB = 0x00; // DDRB.1 = 0 = input PORTB = 0xFF; // PORTB.1 = 1 = internal pullup enabled If i use the analog comparator and select PORTB.1 as AIN1 will the internal pullup be applied to my input signal? I'm hoping someone has personal experience to verify this behavior. Hope this question isn't too 'hardware-oriented' for stack-overflow. Thanks!

    Read the article

  • Update mapping table in Linq

    - by Gary McGill
    I have a table Customers with a CustomerId field, and a table of Publications with a PublicationId field. Finally, I have a mapping table CustomersPublications that records which publications a customer can access - it has two fields: CustomerId field PublicationId. For a given customer, I want to update the CustomersPublications table based on a list of publication ids. I want to remove records in CustomersPublications where the PublicationId is not in the list, and add new records where the PublicationId is in the list but not already in the table. This would be easy in SQL, but I can't figure out how to do it in Linq. For the delete part, I tried: var recordsToDelete = dataContext.CustomersPublications.Where ( cp => (cp.CustomerId == customerId) && ! publicationIds.Contains(cp.PublicationId) ); dataContext.CustomersPublications.DeleteAllOnSubmit(recordsToDelete); ... but that didn't work. I got an error: System.NotSupportedException: Method 'Boolean Contains(Int32)' has no supported translation to SQL So, I tried using Any(), as follows: var recordsToDelete = dataContext.CustomersPublications.Where ( cp => (cp.CustomerId == customerId) && ! publicationIds.Any(p => p == cp.PublicationId) ); ... and this just gives me another error: System.NotSupportedException: Local sequence cannot be used in LINQ to SQL implementation of query operators except the Contains() operator Any pointers? [I have to say, I find Linq baffling (and frustrating) for all but the simplest queries. Better error messages would help!]

    Read the article

  • How to initialize a web app?

    - by Gatis
    My Web App will be deployed as a WAR package in a Jetty instance. It needs to perform a lot of caching before serving requests. How do I call the caching method before anything else? is the a static void main() in the web app standard?

    Read the article

  • arduino emacs development

    - by aaa
    hi. I would like to use emacs as a development environment for arduino programming. If you use emacs to program arduino, can you share some tips or links which you find useful. Is there official (or de facto) emacs mode? Also, am I going to miss something which is in arduino IDE if I use emacs exclusively? thank you .

    Read the article

  • Only allow access of FIle From embed.

    - by KyleT
    Hey All, So I am embedding a PDF file on my page: <embed src="http://www.mywebsite.com/files/ebook.pdf" width="500" height="375"> Is there anyway to prevent any and all access to that file except for when it is being accessed via this embed? Thanks!

    Read the article

  • need a web browser in my desktop application

    - by javadahut
    part of the specification of this desktop application is to have a mini browser built in, so that you can enter URL, and navigate the site as you would on a normal browser. Access to the browser page's DOM is required, should let me programmatically change the rendering view of a page, should be cross-platform, renders javascript JDIC seems outdated and I've heard Mozswing doesn't run on Mac.... Jxbrowser license costs a grand and up. Is Java the wrong platform to be creating such app? Are there any other solutions out there for building an application like this ? Thank you.

    Read the article

  • Non-latin-characters ordering in database with "order by"

    - by nybon
    I just found some strange behavior of database's "order by" clause. In string comparison, I expected some characters such as '[' and '_' are greater than latin characters such as 'i' considering their orders in the ASCII table. However, the sorting results from database's "order by" clause is different with my expectation. Here's my test: SQLite version 3.6.23 Enter ".help" for instructions Enter SQL statements terminated with a ";" sqlite> create table products(name varchar(10)); sqlite> insert into products values('ipod'); sqlite> insert into products values('iphone'); sqlite> insert into products values('[apple]'); sqlite> insert into products values('_ipad'); sqlite> select * from products order by name asc; [apple] _ipad iphone ipod This behavior is different from Java's string comparison (which cost me some time to find this issue). I can verify this in both SQLite 3.6.23 and Microsoft SQL Server 2005. I did some web search but cannot find any related documentation. Could someone shed me some light on it? Is it a SQL standard? Where can I find some information about this? Thanks in advance.

    Read the article

  • Best way to split a string by word (SQL Batch separator)

    - by Paul Kohler
    I have a class I use to "split" a string of SQL commands by a batch separator - e.g. "GO" - into a list of SQL commands that are run in turn etc. ... private static IEnumerable<string> SplitByBatchIndecator(string script, string batchIndicator) { string pattern = string.Concat("^\\s*", batchIndicator, "\\s*$"); RegexOptions options = RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.Multiline; foreach (string batch in Regex.Split(script, pattern, options)) { yield return batch.Trim(); } } My current implementation uses a Regex with yield but I am not sure if it's the "best" way. It should be quick It should handle large strings (I have some scripts that are 10mb in size for example) The hardest part (that the above code currently does not do) is to take quoted text into account Currently the following SQL will incorrectly get split: var batch = QueryBatch.Parse(@"-- issue... insert into table (name, desc) values('foo', 'if the go is on a line by itself we have a problem...')"); Assert.That(batch.Queries.Count, Is.EqualTo(1), "This fails for now..."); I have thought about a token based parser that tracks the state of the open closed quotes but am not sure if Regex will do it. Any ideas!?

    Read the article

  • Entity Framework and differences between Contains between SQL and objects using ToLower

    - by John Ptacek
    I have run into an "issue" I am not quite sure I understand with Entity Framework. I am using Entity Framework 4 and have tried to utilize a TDD approach. As a result, I recently implemented a search feature using a Repository pattern. For my test project, I am implementing my repository interface and have a set of "fake" object data I am using for test purposes. I ran into an issue trying to get the Contains clause to work for case invariant search. My code snippet for both my test and the repository class used against the database is as follows: if (!string.IsNullOrEmpty(Description)) { items = items.Where(r => r.Description.ToLower().Contains(Description.ToLower())); } However, when I ran my test cases the results where not populated if my case did not match the underlying data. I tried looking into what I thought was an issue for a while. To clear my mind, I went for a run and wondered if the same code with EF would work against a SQL back end database, since SQL will explicitly support the like command and it executed as I expected, using the same logic. I understand why EF against the database back end supports the Contains clause. However, I was surprised that my unit tests did not. Any ideas why other than the SQL server support of the like clause when I use objects I populate in a collection instead of against the database server? Thanks! John

    Read the article

  • Writing Device Drivers for Microcontrollers, where to define IO Port pins?

    - by volting
    I always seem to encounter this dilemma when writing low level code for MCU's. I never know where to declare pin definitions so as to make the code as reusable as possible. In this case Im writing a driver to interface an 8051 to a MCP4922 12bit serial DAC. Im unsure how/where I should declare the pin definitions for The CS(chip select) and LDAC(data latch) for the DAC. At the moment there declared in the header file for the driver. Iv done a lot of research trying to figure out the best approach but havent really found anything. Im basically want to know what the best practices... if there are some books worth reading or online information, examples etc, any recommendations would be welcome. Just a snippet of the driver so you get the idea /** @brief This function is used to write a 16bit data word to DAC B -12 data bit plus 4 configuration bits @param dac_data A 12bit word @param ip_buf_unbuf_select Input Buffered/unbuffered select bit. Buffered = 1; Unbuffered = 0 @param gain_select Output Gain Selection bit. 1 = 1x (VOUT = VREF * D/4096). 0 =2x (VOUT = 2 * VREF * D/4096) */ void MCP4922_DAC_B_TX_word(unsigned short int dac_data, bit ip_buf_unbuf_select, bit gain_select) { unsigned char low_byte=0, high_byte=0; CS = 0; /**Select the chip*/ high_byte |= ((0x01 << 7) | (0x01 << 4)); /**Set bit to select DAC A and Set SHDN bit high for DAC A active operation*/ if(ip_buf_unbuf_select) high_byte |= (0x01 << 6); if(gain_select) high_byte |= (0x01 << 5); high_byte |= ((dac_data >> 8) & 0x0F); low_byte |= dac_data; SPI_master_byte(high_byte); SPI_master_byte(low_byte); CS = 1; LDAC = 0; /**Latch the Data*/ LDAC = 1; }

    Read the article

  • Good Starting Points for Optimizing Database Calls in Ruby on Rails?

    - by viatropos
    I have a menu in Rails which grabs a nested tree of Post models, each which have a Slug model associated via a polymorphic association (using the friendly_id gem for slugs and awesome_nested_set for the tree). The database output in development looks like this (here's the full gist): SQL (0.4ms) SELECT COUNT(*) AS count_id FROM "posts" WHERE ("posts".parent_id = 39) CACHE (0.0ms) SELECT "posts".* FROM "posts" WHERE ("posts"."id" = 13) LIMIT 1 CACHE (0.0ms) SELECT "slugs".* FROM "slugs" WHERE ("slugs".sluggable_id = 13 AND "slugs".sluggable_type = 'Post') ORDER BY id DESC LIMIT 1 Slug Load (0.4ms) SELECT "slugs".* FROM "slugs" WHERE ("slugs".sluggable_id = 40 AND "slugs".sluggable_type = 'Post') ORDER BY id DESC LIMIT 1 SQL (0.3ms) SELECT COUNT(*) AS count_id FROM "posts" WHERE ("posts".parent_id = 40) CACHE (0.0ms) SELECT "posts".* FROM "posts" WHERE ("posts"."id" = 13) LIMIT 1 CACHE (0.0ms) SELECT "slugs".* FROM "slugs" WHERE ("slugs".sluggable_id = 13 AND "slugs".sluggable_type = 'Post') ORDER BY id DESC LIMIT 1 Slug Load (0.4ms) SELECT "slugs".* FROM "slugs" WHERE ("slugs".sluggable_id = 41 AND "slugs".sluggable_type = 'Post') ORDER BY id DESC LIMIT 1 ... Rendered shared/_menu.html.haml (907.6ms) What are some quick things I should always do to optimize this from the start (easy things)? Some things I'm thinking now are: Can Rails 3 eager load the whole Post tree + associated Slugs in one DB call? Can I do that easily with named scopes or custom SQL? What is best practice in this situation? Not really thinking about memcached in this situation as that can be applied to much more than just this.

    Read the article

  • How to make a scroller on a micro-processor/-controller?

    - by Louise
    I would like to write a text scroller on a micro-processor with 4 5x7 displays in ANSI-C. Does anyone know of example source code or anything that can help me get started? Update This is the user manual for the micro-processor board I have. On PDF page 17 is a picture of the board with the displays. The code is written in an IDE called "zds2_Z8Encore493.exe" and then flashed to the micro-controller over serial port. I would like the text to cascade from one to the next to the next column-by-column, so it is smooth.

    Read the article

  • Compile time float packing/punning

    - by detly
    I'm writing C for the PIC32MX, compiled with Microchip's PIC32 C compiler (based on GCC 3.4). My problem is this: I have some reprogrammable numeric data that is stored either on EEPROM or in the program flash of the chip. This means that when I want to store a float, I have to do some type punning: typedef union { int intval; float floatval; } IntFloat; unsigned int float_as_int(float fval) { IntFloat intf; intf.floatval = fval; return intf.intval; } // Stores an int of data in whatever storage we're using void StoreInt(unsigned int data, unsigned int address); void StoreFPVal(float data, unsigned int address) { StoreInt(float_as_int(data), address); } I also include default values as an array of compile time constants. For (unsigned) integer values this is trivial, I just use the integer literal. For floats, though, I have to use this Python snippet to convert them to their word representation to include them in the array: import struct hex(struct.unpack("I", struct.pack("f", float_value))[0]) ...and so my array of defaults has these indecipherable values like: const unsigned int DEFAULTS[] = { 0x00000001, // Some default integer value, 1 0x3C83126F, // Some default float value, 0.005 } (These actually take the form of X macro constructs, but that doesn't make a difference here.) Commenting is nice, but is there a better way? It's be great to be able to do something like: const unsigned int DEFAULTS[] = { 0x00000001, // Some default integer value, 1 COMPILE_TIME_CONVERT(0.005), // Some default float value, 0.005 } ...but I'm completely at a loss, and I don't even know if such a thing is possible. Notes Obviously "no, it isn't possible" is an acceptable answer if true. I'm not overly concerned about portability, so implementation defined behaviour is fine, undefined behaviour is not (I have the IDB appendix sitting in front of me). As fas as I'm aware, this needs to be a compile time conversion, since DEFAULTS is in the global scope. Please correct me if I'm wrong about this.

    Read the article

  • Why does stored procedure invalidate SQL Cache Dependency?

    - by Fabio Milheiro
    After many hours, I finally realize that I am working correctly with the Cache object in my ASP.NET application but my stored procedures stops it from working correctly. This stored procedure works correctly: CREATE PROCEDURE [dbo].[ListLanguages] @Page INT = 1, @ItemsPerPage INT = 10, @OrderBy NVARCHAR (100) = 'ID', @OrderDirection NVARCHAR(4) = 'DESC' AS BEGIN SELECT ID, [Name], Flag, IsDefault FROM dbo.Languages END But this (the one I wanted) doesn't: CREATE PROCEDURE [dbo].[ListLanguages] @Page INT = 1, @ItemsPerPage INT = 10, @OrderBy NVARCHAR (100) = 'ID', @OrderDirection NVARCHAR(4) = 'DESC', @TotalRecords INT OUTPUT AS BEGIN SET @TotalRecords = 10 EXEC('SELECT ID, Name, Flag, IsDefault FROM ( SELECT ROW_NUMBER() OVER (ORDER BY ' + @OrderBy + ' ' + @OrderDirection + ') as Row, ID, Name, Flag, IsDefault FROM dbo.Languages) results WHERE Row BETWEEN ((' + @Page + '-1)*' + @ItemsPerPage + '+1) AND (' + @Page + '*' + @ItemsPerPage + ')') END I gave the @TotalRecords parameter the value 10 so you can be sure that the problem is not from the COUNT(*) function which I know is not supported well. Also, when I run it from SQL Server Management Studio, it does exactly what it should do. In the ASP.NET application the results are retrieved correctly, only the cache is somehow unable to work! Can you please help? Maybe a hint I believe that the reason why the dependency HasChanged property is related to the fact that the column Row generated from the ROW_NUMBER is only temporary and, therefore, the SQL SERVER is not able to to say whether the results are changed or not. That's why HasChanged is always set to true. Does anyone know how to paginate results from SQL SERVER without using COUNT or ROW_NUMBER functions?

    Read the article

< Previous Page | 506 507 508 509 510 511 512 513 514 515 516 517  | Next Page >