Search Results

Search found 10815 results on 433 pages for 'stored procedure'.

Page 384/433 | < Previous Page | 380 381 382 383 384 385 386 387 388 389 390 391  | Next Page >

• table column accepting "0" as a member Id

  - by user682417

  I have two tables one is members table with columns member id , member first name, member last name. I have another table guest passes with columns guest pass id and member id and issue date . I have a list view that will displays guest passes details (I.e) like member name and issue date and I have two text boxes those are for entering member name and issue date . member name text box is auto complete text box that working fine.... but the problem is when I am entering the name that is not in member table at this time it will accept and displays a blank field in list view in member name column and member id is stored as "0" in guest pass table ...... I don't want to display the member name empty blank and I don t want to store "0" in guest pass table and this is the insert statement sql2 = @"INSERT INTO guestpasses(member_Id,guestPass_IssueDate)"; sql2 += " VALUES("; sql2 += "'" + tbCGuestPassesMemberId.Text + "'"; sql2 += ",'" + tbIssueDate.Text + "'"; guestpassmemberId = memberid is there any validation that need to be done can any one suggestions on this pls... and this is the auto complete text box statement sql = @"SELECT member_Id FROM members WHERE concat(member_Firstname,'',member_Lastname) ='" + tbMemberName.Text+"'"; if (dt != null) { if (dt.Rows.Count > 0) { tbCGuestPassesMemberId.Text = Convert.ToInt32(dt.Rows[0] ["member_Id"]).ToString(); } } can any one help me on this ... is there any type of validation with sql query pls help me .....

  Read the article

• Parsing string based on initial format

  - by Kayla

  I'm trying to parse a set of lines and extract certain parts of the string based on an initial format (reading a configuration file). A little more explanation: the format can contain up to 4 parts to be formatted. This case, %S will skip the part, %a-%c will extract the part and will be treated as a string, %d as int. What I am trying to do now is to come up with some clever way to parse it. So far I came up with the following prototype. However, my pointer arithmetic still needs some work to skip/extract the parts. Ultimately each part will be stored on an array of structs. Such as: struct st_temp { char *parta; char *partb; char *partc; char *partd; }; ... #include <stdio.h> #include <string.h> #define DIM(x) (sizeof(x)/sizeof(*(x))) void process (const char *fmt, const char *line) { char c; const char *src = fmt; while ((c = *src++) != '\0') { if (c == 'S'); // skip part else if (c == 'a'); // extract %a else if (c == 'b'); // extract %b else if (c == 'c'); // extract %c else if (c == 'd'); // extract %d (int) else { printf("Unknown format\n"); exit(1); } } } static const char *input[] = { "bar 200.1 / / (zaz) - \"bon 10\"", "foo 100.1 / / (baz) - \"apt 20\"", }; int main (void) { const char *fmt = "%S %a / / (%b) - \"%c %d\""; size_t i; for(i = 0; i < DIM (input); i++) { process (fmt, input[i]); } return (0); }

  Read the article

• Create an index only on certain rows in mysql

  - by dhruvbird

  So, I have this funny requirement of creating an index on a table only on a certain set of rows. This is what my table looks like: USER: userid, friendid, created, blah0, blah1, ..., blahN Now, I'd like to create an index on: (userid, friendid, created) but only on those rows where userid = friendid. The reason being that this index is only going to be used to satisfy queries where the WHERE clause contains "userid = friendid". There will be many rows where this is NOT the case, and I really don't want to waste all that extra space on the index. Another option would be to create a table (query table) which is populated on insert/update of this table and create a trigger to do so, but again I am guessing an index on that table would mean that the data would be stored twice. How does mysql store Primary Keys? I mean is the table ordered on the Primary Key or is it ordered by insert order and the PK is like a normal unique index? I checked up on clustered indexes (http://dev.mysql.com/doc/refman/5.0/en/innodb-index-types.html), but it seems only InnoDB supports them. I am using MyISAM (I mention this because then I could have created a clustered index on these 3 fields in the query table). I am basically looking for something like this: ALTER TABLE USERS ADD INDEX (userid, friendid, created) WHERE userid=friendid

  Read the article

• PHP & MySQL storing multiple values in a database.

  - by R.I.P.coalMINERS

  I'm basically a front end designer and new to PHP and MySQL but I want a user to be able to store multiple names and there meanings in a MySQL database table named names using PHP I will dynamically create form fields with JQuery every time a user clicks on a link so a user can enter 1 to 1,000,000 different names and there meanings which will be stored in a table called names. All I want to know is how can I store multiple names and there meanings in a database and then display them back to the user for them to edit or delete using PHP MySQL? I created the MySQL table already. CREATE TABLE names ( id INT UNSIGNED NOT NULL AUTO_INCREMENT, userID INT NOT NULL, name VARCHAR(255) NOT NULL, meaning VARCHAR(255) NOT NULL, PRIMARY KEY (id) ); Here is the HTML. <form method="post" action="index.php"> <ul> <li><label for="name">Name: </label><input type="text" name="name" id="name" /></li> <li><label for="meaning">Meaning: </label><input type="text" name="meaning" id="meaning" /></li> <li><input type="submit" name="submit" value="Save" /> <input type="hidden" name="submit" value="true" /></li> </ul> </form>

  Read the article

• Should I be backing up a webapp's data to another host continuously ?

  - by user196289

  I have webapp in development. I need to plan for what happens if the host goes down. I will lose some very recent session status (which I can live with) and everything else should be persistently stored in the database. If I am starting up again after an outage, can I expect a good host to reconstruct the database to within minutes of where I was up to ? Or seconds ? Or should I build in a background process to continually mirror the database elsewhere ? What is normal / sensible ? Obviously a good host will have RAID and other redundancy so the likelihood of total loss should be low, and if they have periodic backups I should lose only very recent stuff but this is presumably likely to be designed with almost static web content in mind, and my site is transactional with new data being filed continuously (with a customer expectation that I don't ever lose it). Any suggestions / advice ? Are there off the shelf frameworks for doing this ? (I'm primarily working in Java) And should I just plan to save the data or should I plan to have an alternative usable host implementation ready to launch in case the host doesn't come back up in a suitable timeframe ?

  Read the article

• PHP Saving information to MySQL but not using hard coded code

  - by Homer_J

  Hi guys, Thanks everyone for assisting me but know I'm well and truely stuck...hopefully someone can advise? My current code that saves to a MySQL database: $q1 = $_POST["q1"]; $q2 = $_POST["q2"]; $q3 = $_POST["q3"]; $q4 = $_POST["q4"]; $q5 = $_POST["q5"]; $q6 = $_POST["q6"]; $q7 = $_POST["q7"]; $q8 = $_POST["q8"]; $proc = mysqli_prepare($link, "INSERT INTO tresults_bh_main (respondent_id, ip, browser, q1, q2, q3, q4, q5, q6, q7, q8) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?);"); mysqli_stmt_bind_param($proc, "issiiiiiiii", $respondent_id, $ip, $browser, $q1, $q2, $q3, $q4, $q5, $q6, $q7, $q8); At the moment this is all hard coded and I need it to use variables: I have an array which stores the following information: $qs['questions'] - stores, for example q1, q2, q3, q4 etc - obviously these change both in terms of of numbers, ie. q10, q11, q12 and also the amount in the array - so there could be 4 q's or 10 q's stored in the array. What I struggling to get my head around is how I would set-up this hard coded page to work with my variables. If anyone can help, much appreciated. Homer.

  Read the article

• XSLT; parse escaped text to a node-set and extract subelements

  - by Tom W

  Hello SO; I've been fighting with this problem all day and am just about at my wit's end. I have an XML file in which certain portions of data are stored as escaped text but are themselves well-formed XML. I want to convert the whole hierarchy in this text node to a node-set and extract the data therein. No combination of variables and functions I can think of works. The way I'd expect it to work would be: <xsl:variable name="a" select="InnerXML"> <xsl:for-each select="exsl:node-set($a)/*"> 'do something </xsl:for-each> The input element InnerXML contains text of the form <root><element a>text</element a><element b><element c/><element d>text</element d></element b></root> but that doesn't really matter. I just want to navigate the xml like a normal node-set. Where am I going wrong?

  Read the article

• Database tables with dynamic information

  - by Tim Fennis

  I've googled this and found that it's almost impossible to create a database with dynamic collumns. I'll explain my problem first. I am making a webshop for a customer. It has multiple computer products for sale. CPU's HDD's RAM ect. All these products have different properties, a CPU has an FSB, RAM has a CAS latency. But this is very inconvenient because my orders table needs foreign keys to different tables which is impossible. An other option is to store all the product specific information in a varchar or blob field and let PHP figure it out. The problem with this solution is that the website needs a PC builder. A step-by-step guide to building your PC. So for instance if a customer decides he wants a new "i7 920" or whatever i want to be able to sellect all motherboards for socket 1366, which is impossible because all the data is stored in one field. I know it's possible to select all motherboards form the DB and let PHP figure out which ones are for socket 1366 but i was wondering, is there a better solution?

  Read the article

• WPF Databinding With A Collection Object

  - by Randster

  Argh, although I've been googling, I really would appreciate it if someone could break my problem down as all the code examples online are confusing me more than assisting (perhaps it's just late)... I have a simple class as defined below: public class Person { int _id; string _name; public Person() { } public int ID { get { return _id; } set { _id = value; } } public string Name { get { return _name; } set { _name = value; } } } that is stored in a database, and thru a bit more code I put it into an ObservableCollection object to attempt to databind in WPF later on: public class People : ObservableCollection<Person> { public People() : base() { } public void Add(List<Person> pListOfPeople) { foreach (Person p in pListOfPeople) this.Add(p); } } In XAML, I have myself a ListView that I would like to populate a ListViewItem (consisting of a textblock) for each item in the "People" object as it gets updated from the database. I would also like that textblock to bind to the "Name" property of the Person object. I thought at first that I could do this: lstPeople.DataContext = objPeople; where lstPeople is my ListView control in my XAML, but that of course does nothing. I've found TONS of examples online where people through XAML create an object and then bind to it through their XAML; but not one where we bind to an instantiated object and re-draw accordingly. Could someone please give me a few pointers on: A) How to bind a ListView control to my instantiated "People" collection object? B) How might I apply a template to my ListView to format it for the objects in the collection? Even links to a decent example (not one operating on an object declared in XAML please) would be appreciated. Thanks for your time.

  Read the article

• Safe way for getting/finding a vertex in a graph with custom properties -> good programming practice

  - by Shadow

  Hi, I am writing a Graph-class using boost-graph-library. I use custom vertex and edge properties and a map to store/find the vertices/edges for a given property. I'm satisfied with how it works, so far. However, I have a small problem, where I'm not sure how to solve it "nicely". The class provides a method Vertex getVertex(Vertexproperties v_prop) and a method bool hasVertex(Vertexproperties v_prop) The question now is, would you judge this as good programming practice in C++? My opinion is, that I have first to check if something is available before I can get it. So, before getting a vertex with a desired property, one has to check if hasVertex() would return true for those properties. However, I would like to make getVertex() a bit more robust. ATM it will segfault when one would directly call getVertex() without prior checking if the graph has a corresponding vertex. A first idea was to return a NULL-pointer or a pointer that points past the last stored vertex. For the latter, I haven't found out how to do this. But even with this "robust" version, one would have to check for correctness after getting a vertex or one would also run into a SegFault when dereferencing that vertex-pointer for example. Therefore I am wondering if it is "ok" to let getVertex() SegFault if one does not check for availability beforehand?

  Read the article

• Django GenericRelation doesn't save related object's id - is this a bug or am I doing it wrong?

  - by pinkeen

  I have a model with a generic relation (call it A), when creating an instance of this object I pass an instance of another model (call it B) as the initializer of the content_object field (via kwargs of the constructor). If I don't save B before creating A then when saving A the content_object_id is saved to the db as NULL. If I save B before passing it to the constructor of A then everything's allright. It's not logical. I assumed that the ID of the related object (B) is fetched when doing A.save() and it should throw some kind of an exception if B isn't saved yet but it just fails silently. I don't like the current solution (saving B beforhand) because we don't know yet if I will be always willing to keep the object, not just scrap it, and there are performance considerations - what if I will add some another data and save it once more shortly after. class BaseNodeData(models.Model): ... extnodedata_content_type = models.ForeignKey(ContentType, null=True) extnodedata_object_id = models.PositiveIntegerField(null=True) extnodedata = generic.GenericForeignKey(ct_field='extnodedata_content_type', fk_field='extnodedata_object_id') class MarkupNodeData(models.Model): raw_content = models.TextField() Suppose we do: markup = MarkupNodeData(raw_content='...') base = BaseNodeData(..., extnodedata=markup) markup.save() base.save() # both records are inserted to the DB but base is stored with extnodedata_object_id=NULL markup = MarkupNodeData(raw_content='...') base = BaseNodeData(..., extnodedata=markup) base.save() markup.save() # no exception is thrown and everything is the same as above markup = MarkupNodeData(raw_content='...') markup.save() base = BaseNodeData(..., extnodedata=markup) base.save() # this works as expected Of course I can do it this way, but it doesn't change anything: base = BaseNodeData(...) base.extnodedata = markup My question is - is this a bug in django which I should report or maybe I'm doing something wrong. Docs on GenericRelations aren't exactly verbose.

  Read the article

• jQuery: Triggering a click on an img not working

  - by Twecs

  I'm testing in Chrome. I have a bunch of 'add item' icons on screen that the user can click in order to add that one item to the database. I also have a button at the botton of that list, which should add the whole list of items. It seems to me that the easiest way to do this is to trigger the 'click' event for all these icons (the reason I'm doing it via the icons is that items-specific values are stored as attributes of the div in which the icon resides). However, I can't get it to work: the event handlers for the individual icons work perfectly, and the event handler for the add-them-all button does give me an alert if I put that in. But if I add the I read some posts that suggest browsers don't allow you to trigger click events, so I added a 'hover' event listener to the icons to see if the problem is in the type of event I want to trigger. Answer: no, same story: the alert will work, but the trigger won't. I have placed the icon event listener in the code before the button event listener. What's going on? Twecs

  Read the article

• Maximum length of a std::basic_string<_CharT> string

  - by themoondothshine

  Hey all, I was wondering how one can fix an upper limit for the length of a string (in C++) for a given platform. I scrutinized a lot of libraries, and most of them define it arbitrarily. The GNU C++ STL (the one with experimental C++0x features) has quite a definition: size_t npos = size_t(-1); /*!< The maximum value that can be stored in a variable of type size_t */ size_t _S_max_len = ((npos - sizeof(_Rep_base))/sizeof(_CharT) - 1) / 4; /*!< Where _CharT is a template parameter; _Rep_base is a structure which encapsulates the allocated memory */ Here's how I understand the formula: The size_t type must hold the count of units allocated to the string (where each unit is of type _CharT) Theoretically, the maximum value that a variable of type size_t can take on is the total number of units of 1 byte (ie, of type char) that may be allocated The previous value minus the overhead required to keep track of the allocated memory (_Rep_base) is therefore the maximum number of units in a string. Divide this value by sizeof(_CharT) as _CharT may require more than a byte Subtract 1 from the previous value to account for a terminating character Finally, that leave the division by 4. I have absolutely no idea why! I looked at a lot of places for an explanation, but couldn't find a satisfactory one anywhere (that's why I've been trying to make up something for it! Please correct me if I'm wrong!!).

  Read the article

• Can I make a derived class inherit a derived member from its base class in Java?

  - by Eric

  I have code that looks like this: public class A { public void doStuff() { System.out.print("Stuff successfully done"); } } public class B extends A { public void doStuff() { System.out.print("Stuff successfully done, but in a different way"); } public void doMoreStuff() { System.out.print("More advanced stuff successully done"); } } public class AWrapper { public A member; public AWrapper(A member) { this.member = member; } public void doStuffWithMember() { a.doStuff(); } } public class BWrapper extends AWrapper { public B member; public BWrapper(B member) { super(member); //Pointer to member stored in two places: this.member = member; //Not great if one changes, but the other does not } public void doStuffWithMember() { member.doMoreStuff(); } } However, there is a problem with this code. I'm storing a reference to the member in two places, but if one changes and the other does not, there could be trouble. I know that in Java, an inherited method can narrow down its return type (and perhaps arguments, but I'm not certain) to a derived class. Is the same true of fields?

  Read the article

• servlet ArrayList and HashMap problem witch result

  - by nonameplum

  Hi, I have that code List<Map<String, Object>> data = new ArrayList<Map<String, Object>>(); Map<String, Object> item = new HashMap<String, Object>(); data.clear(); item.clear(); int i = 0; while (i < 5){    item.put("id", i);    i++;    out.println("id: " + item.get("id"));    out.println("--------------------------");    data.add(item); } for(i=0 ; i<5 ; i++){    out.println("print data[" + i + "]" + data.get(i)); } Result of that is: id: 0 -------------------------- id: 1 -------------------------- id: 2 -------------------------- id: 3 -------------------------- id: 4 -------------------------- print data[0]{id=4} print data[1]{id=4} print data[2]{id=4} print data[3]{id=4} print data[4]{id=4} Why only last element is stored?

  Read the article

• Problem in data binding in NSString?

  - by Rajendra Bhole

  Hi, I selecting the row of the table. The text of the row i stored in the application delegate object as a NSString. That NSString i want to retrieving or binding in SELECT statement of SQLite query, For that i written code in the TableView Class (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { selectedText = [appDelegate.categoryArray objectAtIndex:indexPath.row]; appDelegate.selectedTextOfRow = selectedText; ListOfPrayersViewController *listVC = [[ListOfPrayersViewController alloc] init]; [self.navigationController pushViewController:listVC animated:YES]; [listVC release]; } and database class class code is. + (void) getDuas:(NSString *)dbPath{ if(sqlite3_open([dbPath UTF8String], &database) == SQLITE_OK){ SalahAppDelegate *appDelegate = (SalahAppDelegate *)[[UIApplication sharedApplication] delegate]; NSString *categoryTextForQuery =[NSString stringWithFormat:@"SELECT Category FROM Prayer WHERE Category ='%s'", appDelegate.selectedTextOfRow ]; NSLog(@"The Text %@", categoryTextForQuery); //const char *sqlQuery1 = (char *)categoryTextForQuery; //const char *sqlQuery = "SELECT Category FROM Prayer WHERE Category = 'Invocations for the beginning of the prayer'"; sqlite3_stmt *selectstmt; if(sqlite3_prepare_v2(database, [categoryTextForQuery UTF8String], -1, &selectstmt, NULL) == SQLITE_OK){ appDelegate.duasArray =[[NSMutableArray alloc] init]; while(sqlite3_step(selectstmt) == SQLITE_ROW){ NSString *dua = [[NSString alloc] initWithCString:(char *)sqlite3_column_text(selectstmt,0) encoding:NSASCIIStringEncoding]; Prayer *prayerObj = [[Prayer alloc] initwithDuas:dua]; prayerObj.DuaName = dua; [appDelegate.duasArray addObject:prayerObj]; } } } } The code is comes out of loop on the statement or starting the loop of the while(sqlite3_step(selectstmt) == SQLITE_ROW) Why? How i bind the table selected text in SELECT statement of sqlite?

  Read the article

• Storing large json strings to database + hash

  - by Guy

  I need to store quiete large JSON data strings to the database. I am using gzip to compress the string and therefore BLOB MySQL data type to store it. However, only 5% of all the requests contain unique data and only unique data ought to be stored to the database. My approach is as follows. array_multisort data (array [a, b, c] is virtually the same as [a, c, b]). json_encode data (json_encode is faster than serialize; we need string array representation for the step 3). sha1 data (slower than md5, though less possible the collisions). Check if the hash exists in the database. 5.1 yes – do not insert the data. 5.2. no – gzip the data and store it along the hash. Is there anything about this (apart from storing JSON data to the database in the first place) that sounds fishy or should be done a different way? p.s. We are talking about a database with roughly 1kk unique records being created every month.

  Read the article

• Passing list of items from Controller/Model to a variable in javascript - autocomplete

  - by newbie_developer

  I've a method in a NamesModel which fetches all the names and returns a list of names: public static List<NamesModel> GetAllNames() { List<NamesModel> names = new List<NamesModel>(); // // code to fetch records // return names; } In my controller: public ActionResult Index() { NamesModel model = new NamesModel(); model.GetAllNames(); return View(model); } In the view, I've got a textbox: @Html.TextBox("search-name") Now in my javascript, I want to fetch all names into a variable either from a model (from method) or from controller, for example: <script type="text/javascript"> $(function () { var names = ........... $(document).ready(function () { $('#search-name').autocomplete({ source: names }); }); }); </script> If I use hardcoding then it works but I want to use the names stored in the db. Is it possible? hardcoding example: var names = ["abc", "xyz"];

  Read the article

• login script in php using session variables

  - by kracekumar

  ? username: '; } else { $user=$_POST['user']; $query="select name from login where name='$user'"; $result=mysql_query($query) or die(mysql_error()); $rows=mysql_num_rows($result)or die(mysql_error()); session_start(); //echo "results"; $username=mysql_fetch_array($result) or die(mysql_error()); $fields=mysql_num_fields($result) or die(mysql_error()); echo "username:$username[0]"; $_SESSION['username']=$username[0]; $sesion_username=$_SESSION['username']; //echo "rows:$rows"." "."fields:$fields"; echo""."username:$sesion_username"; } ? i wanted to create a site where user can login and upload their details depending on their user name have stored their details in a database,the problem i am facing is two people 'a' and 'b' login one after other session_variable $_SESSION['username'] will have 'b's' username ,so i can't display 'a's' details now. . . . what i want to achieve is when a user logins in i want to store his name and other details in session variable and navigate him according and display his details

  Read the article

• Can't call an object method. PHP reports variable undefined

  - by user1285697

  This is the weirdest bug! It is probably something silly, but I have no idea how to fix it. If anyone could help, I would be most grateful! I have three files, one is called items.php, another is called tableFunctions.php, and the third is called mysql.php. I use two global objects called 'mysql' and 'tableFunctions'. They are stored in the files 'mysql.php', and 'tableFunctions.php', respectively. In each file, I create an instance of its object, assigning it to the global variable $_mysql, or $_table. like this: In the file mysql.php: global $_mysql; $_mysql = new mysql(); In the file tableFunctions.php: global $_table; $_table = new tableFunctions(); Here's how it is supposed to work: The items.php file includes the tableFunctions.php file... Which in turn, needs the mysql.php file, so it includes it too. In the items.php file, I call the method getTable(), which is contained in the object tableFunctions.(and in the variable $_table.) Like this: $t = $_table->getTable('items'); The getTable function calls the method, arrayFromResult(), which is contained within in the object mysql.(and in the variable $_mysql.) Like this: $result = $_mysql->arrayFromResult($r); That's where I get the error. PHP says that the variable '$_mysql' is undefined, but I defined it in the 'mysql.php' file.(see above) I also included mysql.php with the following code: include_once 'mysql.php'; I have no idea what is wrong! If anyone can help that would be much appreciated. The source files can be downloaded with the following link: https://www.dropbox.com/sh/bjj2gyjsybym89r/YLxqyNvQdn

  Read the article

• Manipulating data in sql / asp.net / c# - how?

  - by SLC

  Not sure how to word the question... Basically, so far all my SQL stuff has been stored procedures and dumped into a gridview. The odd case where I had to perform an action based on a value (such as highlighting a row green if a certain value was true) were done as the gridview was rendering in one of the overrides. Now however I have to do something far more complicated - pull three sets of data down, run a series of checks on all three and some date related checks and stuff, then populate a gridview with some of the items. In logic terms, I want to run three queries, and store the lists of results (presumably in Lists?) then run some logic, then populate the gridview. Specifically what I don't know how to do is: Best way of pulling the data, and putting it into a List or other datastructure that lets me easily run through it, and retrieve data based on column (myList.age, or more likely, myList["Age"]). One I have compared the data, I assume I create a new list that will be put into the gridview... how do I put the contents of a list INTO a gridview? How would I add other stuff such as buttons or checkboxes at the same time? Any nudge in the right direction would be appreciated! Particularly doing cool stuff with lists and sql (if there is anything cool you can do with them)

  Read the article

• What is the best way to create a running integer id on the AppEngine data storage?

  - by Freed

  For various reasons, I need a unique running integer id for my entities stored on the Google AppEngine. The automatically generated key sort of has this behaviour, but it doesn't start from 1 (or 0) and doesn't guarantee that the generated integer part will come from a continuous sequence. What would be the best way to efficiently implement this on AppEngine? Is there any support from the storage system? To add to the complexity, I might need to do this over entities from different entity groups, meaning I can't just get the highest id right now and save an entity with the next id in a transaction. Might memcache be the way to go..? Edit: I havn't yet implemented this, but to clarify on the memcache idea. I know memcache is unreliable, but in practice it probably won't lose data "too often" to hurt performance. Basically, I would have a memcache entry for the last used id, update it (somehow atomically) whenever I create a new entity and use that id. In the case of memcache not having a value for this entry, I'd get the highest id so far by doing a query on my entities sorted by the id and update memcache (unless someone else had already done so). The only problem I can see with this right now would be atomicity of the operation as a whole if the save of my new entity was also part of a transaction. Thoughts..?

  Read the article

• memcached: which is faster, doing an add (and checking result), or doing a get (and set when returni

  - by Mike Sherov

  The title of this question isn't so clear, but the code and question is straightforward. Let's say I want to show my users an ad once per day. To accomplish this, every time they visit a page on my site, I check to see if a certain memcache key has any data stored on it. If so, don't show an ad. If not, store the value '1' in that key with an expiration of 86400. I can do this 2 ways: //version a $key='OPD_'.date('Ymd').'_'.$type.'_'.$user; if($memcache->get($key)===false){ $memcache->set($key,'1',false,$expire); //show ad } //version b $key='OPD_'.date('Ymd').'_'.$type.'_'.$user; if($memcache->add($key,'1',false,$expire)){ //show ad } Now, it might seem obvious that b is better, it always makes 1 memcache call. However, what is the overhead of "add" vs. "get"? These aren't the real comparisons... and I just made up these numbers, but let's say 1 add ~= 1 set ~= 5 get in terms of effort, and the average user views 5 pages a day: a: (5 get * 1 effort) + (1 set * 5 effort) = 10 units of effort b: (5 add * 5 effort) = 25 units of effort Would it make sense to always do the add call? Is this an unnecessary micro-optimization?

  Read the article

• new project app; use entirely node.js

  - by Jared

  I have been looking into Node.js, express and Nowjs and love how easy it is to have real time interactions between clients. My background is mostly from CodeIgniter MVC using PHP and MYSql. I want to re make a current web project of mine from scratch to make everything better and more real time with this newer technology. After researching and doing test examples I want to use node.js , express and Nowjs for the real time interactions once someone connects to the socket.io to pull data back to clients. But use Code Igniter for the control of the site and user management , possible shopping cart/store , pretty much everything else. This is purely due to time constraints and that I am already familiar with doing it that way. I have been looking at MongoDB as an alternative to MySql, Basically the app is going to be multiple chat rooms all on one page. with the ability of notifications and private messaging. Lots of data transfer and images. before I started piecing it together I wanted to get people who have already done something similar. My model would use Code Igniter and MySQL to render the page and then connect them onto a node.js server and broadcast using express and nowjs would using a mongoDB be better than mySQL for tons of messages and data being stored or MYSQL? Also does it make since to not make the whole site on Node.js , kinda piece it together like that?

  Read the article

• How to structure Javascript programs in complex web applications?

  - by mixedpickles

  Hi there. I have a problem, which is not easily described. I'm writing a web application that makes heavy usage of jquery and ajax calls. Now I don't have experience in designing the architecture for javascript programms, but I realize that my program has not a good structure. I think I have to many identifiers referring to the same (at least more or less) thing. Let's have an exemplary look at an arbitrary UI widget: The eventhandlers use DOM elements as parameters. The DOM element represents a widget in the browser. A lot of times I use jQuery objects (I think they are basically a wrapper around DOM elements) to do something with the widget. Sometimes they are used transiently, sometimes they are stored in a variable for later purposes. The ajax function calls use strings identifiers for these widgets. They are processed server side. Beside that I have a widget class whose instances represents a widget. It is instantiated through the new operator. Now I have somehow four different object identifiers for the same thing, which needs to be kept in sync until the page is loaded anew. This seems not to be a good thing. Any advice?

  Read the article

< Previous Page | 380 381 382 383 384 385 386 387 388 389 390 391  | Next Page >