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• CodeIgniter Active Record Queries W/ Sub Queries

  - by Mike

  Question: I really am trying to stick to using ActiveRecord and not using straight SQL.. can someone help me convert this to activerecord? Trying to get the email address and contact name from another table. map_userfields table is a one to many, multiple rows per p.id. one row per p.id per uf.fieldid. see this screenshot for a reference to the map_userfields table: Current Non active record query SELECT p.id, (SELECT uf.fieldvalue FROM map_userfields uf WHERE uf.pointid = p.id AND uf.fieldid = 20) As ContactName, (SELECT uf.fieldvalue FROM map_userfields uf WHERE uf.pointid = p.id AND uf.fieldid = 31) As ContactEmail FROM map_points p WHERE /** $pointCategory is an array of categories to look for **/ p.type IN($pointCategory) Note: I am using CodeIgniter 2.1.x, MySQL 5.x, php 5.3

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• Howto check if a object is connected to another in hibernate

  - by codevourer

  Imagine two domain object classes, A and B. A has a bidirectional one-to-many relationship to B. A is related to thousands of B. The relations must be unique, it's not possible to have a duplicate. To check if an instance of B is already connected to a given instance of A, we could perform an easy INNER JOIN but this will only ensure the already persisted relations. What about the current transient relations? class A { @OneToMany private List<B> listOfB; } If we access the listOfB and perform a check of contains() this will fetch all the connected instances of B lazy from the datasource. I only want to validate them by their primary-key. Is there an easy solution where I can do things like "Does this instance of A is connected with this instance of B?" Without loading all these data into memory and perform a based on collections?

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• MySQL - Join as zero if record Not IN

  - by Zurahn

  To explain by example, take two tables, A and B Table A id foo 1 x 2 y 3 z Table B id aid bar 1 3 50 2 1 100 An example join SELECT foo, bar FROM a, b WHERE a.id = b.aid; Garners a result of foo bar z 50 x 100 What I would like to do is get all values of foo and for any instances where there isn't a corresponding bar value, return 0 for that column. My best guess was something along the lines of SELECT foo, bar AS br FROM a, b WHERE a.id = b.aid OR a.id NOT IN (SELECT aid FROM b); But that returns duplicates and non-zero values for bar. Possible?

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• How to do @OneToMany mapping on the field using @transient

  - by hemal

  I am using JPA annotations here , I want to do @OneToMany mapping on filed declared as @Transient. is it possible to do mapping on @transient field ? SimpleTagGroup.java @Entity @Table(name = "TagGroup") public class SimpleTagGroup { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private long id = -1; @NotNull private String tagGroupName; @OneToMany(fetch = FetchType.EAGER) @JoinTable(name = "TagMapping", joinColumns = @JoinColumn(name = "id"), inverseJoinColumns = @JoinColumn(name = "tagId")) @Transient private List<SimpleTag> tags; SimpleTag.java @Entity @Table(name = "Tag") public class SimpleTag implements Tag{ @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private long id = -1; @NotNull private String tagValue;

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• Can I make PDOStatement->fetchObject not use non-member variables?

  - by threendib

  Lets say I have a class like this: Class User { var $id var $name; } And I run a query using PDO in php like so: $stm = $db->prepare('select * from users where id = :id'); $r = $stm->execute(array(':id' => $id)); $user = $r->fetchObject('User'); If I vardump my user object it has all kinds of other fields in it that I have not defined in the User class. Obviously I could make my query specific so that it only gives me back the fields I need/want. But if I don't want to do that is there any way to make this work the way I want it to? I like the idea of fetchObject, because it's one line of code to create this object and set member variables for me. I just don't want it to set variables I haven't defined in my class.

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• Linq query with Array in where clause?

  - by Matt Dell

  I have searched for this, but still can't seem to get this to work for me. I have an array of Id's associated with a user (their Organization Id). These are placed in an int[] as follows: int[] OrgIds = (from oh in this.Database.OrganizationsHierarchies join o in this.Database.Organizations on oh.OrganizationsId equals o.Id where (oh.Hierarchy.Contains(@OrgId)) || (oh.OrganizationsId == Id) select o.Id).ToArray(); The code there isn't very important, but it shows that I am getting an integer array from a Linq query. From this, though, I want to run another Linq query that gets a list of Personnel, that code is as follows: List<Personnel> query = (from p in this.Database.Personnels where (search the array) select p).ToList(); I want to add in the where clause a way to select only the users with the OrganizationId's in the array. So, in SQL where I would do something like "where OrganizationId = '12' or OrganizationId = '13' or OrganizatonId = '17'." Can I do this fairly easily in Linq / .NET?

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• jQuery form serialize - empty string

  - by user137348

  My html: <script type="text/javascript"> $(function() { $("#bt1").click(function() { var f = $("#form1"); var formData = f.serialize(); alert(formData); }); }); </script> <div id="div1"> <form id="form1" action="/Home/Test1" method="post" name="down"> <div id="div2"> <input id="input1" type="text" value="2" /> </div> </form> </div> <input type="submit" id="bt1" /> When I fire up the click event, formData is empty. I'm using jQuery 1.4.2.

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• load balancing in Tomcat

  - by Alvin

  Hi All, I want to implement the load balancing in tomcat 6.0 so that we can create more than one instance of a tomcat and when any of the instance is down then other instance will run our application. so that our application will never be down even when the large number of concurrent request comes. But i have no idea to implement it. Please give your precious suggestions.

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• how to find datakeys in oncheckedchanged event ?

  - by subodh

  <asp:Panel ID="pnlFocusAreaPanel" runat="server" GroupingText="Focus Area" Width="800"> <table cellspacing="0" cellpadding="0" width="750"> <tr> <td> <asp:GridView ID="dgFocusAreaDetails" runat="server" Width="100%" CssClass="dgStyle" AutoGenerateColumns="False" BorderColor="Silver" BorderWidth="1px" CellPadding="0" ShowHeader="False" OnSelectedIndexChanged="dgFocusAreaDetails_SelectedIndexChanged" DataKeyNames="PK_ID"> <FooterStyle Font-Underline="True" HorizontalAlign="Center" VerticalAlign="Middle"> </FooterStyle> <Columns> <asp:TemplateField HeaderText="Focus Area" HeaderStyle-BackColor="Silver"> <ItemStyle Width="90%" /> <ItemTemplate> <asp:Label runat="server" ID="lblFocusArea" Text='<%# DataBinder.Eval(Container.DataItem, "FOCUS_AREA_NAME").ToString()%>'> </asp:Label> </ItemTemplate> </asp:TemplateField> <asp:TemplateField HeaderText="Is Current Valid" HeaderStyle-BackColor="Silver"> <ItemStyle Width="10%" HorizontalAlign="Center" /> <ItemTemplate> <asp:CheckBox ID="chkFocusArea" runat="server" OnCheckedChanged="OnCheckChangedEvent" AutoPostBack="true" /> </ItemTemplate> </asp:TemplateField> </Columns> </asp:GridView> </td> </tr> <tr> <td align="left"> <asp:TextBox ID="txtFocusArea" runat="server" Width="300px" CausesValidation="true" CssClass="txtStyle" ValidationGroup="focusArea"> </asp:TextBox> <cc1:TextBoxWatermarkExtender ID="txtFocusAreaWaterMark" runat="server" TargetControlID="txtFocusArea" WatermarkText="Add Focus Area" WatermarkCssClass="WaterMarkStyle"> </cc1:TextBoxWatermarkExtender> <asp:Button ID="btnAddFocusArea" runat="server" Text="AddFocusArea" CssClass="btnStyle" OnClick="btnAddFocusArea_Click" CausesValidation="true" ValidationGroup="focusArea" /> <asp:RequiredFieldValidator ID="reqtxtFocusArea" runat="server" ControlToValidate="txtFocusArea" ErrorMessage="Please enter focus area" Display="Dynamic" ValidationGroup="focusArea"> </asp:RequiredFieldValidator> <asp:RegularExpressionValidator ID="regexFocusArea" runat="server" ErrorMessage="Invalid characters(<,>,#)" ControlToValidate="txtFocusArea" ValidationExpression="^([^&lt;#&gt;]*)$" ValidationGroup="focusArea" Display="Dynamic" SetFocusOnError="true"> </asp:RegularExpressionValidator> </td> </tr> </table> </asp:Panel> and in code behind protected void btnAddFocusArea_Click(object sender, EventArgs e) { string strFocusArea = txtFocusArea.Text; OleDbConnection myConnection = new OleDbConnection(ConfigurationSettings.AppSettings["SQLConnectionString"]); if (strFocusArea == string.Empty || strFocusArea == txtFocusAreaWaterMark.WatermarkText) { lblError.Text = "Focus area is not entered"; } else { string insertQuery = "INSERT INTO LK_CODECAT_FOCUS_AREA(FOCUS_AREA_NAME,FK_ADDED_BY,ADDED_ON) "+ " VALUES('" + strFocusArea + "', "+Session["UserID"] +", GETDATE())"; try { myConnection.Open(); OleDbCommand myCommandToInsert = new OleDbCommand(insertQuery, myConnection); myCommandToInsert.ExecuteNonQuery(); } catch(Exception exc) { ExceptionLogger.LogException(exc); } finally { if (myConnection != null) { myConnection.Close(); } } PopulateFocusArea(); } txtFocusArea.Text = txtFocusAreaWaterMark.WatermarkText; } private void PopulateFocusArea() { OleDbConnection myConnection = new OleDbConnection(ConfigurationSettings.AppSettings["SQLConnectionString"]); string selectQuery = "SELECT PK_ID, FOCUS_AREA_NAME, IS_CURRENT_FOCUS FROM LK_CODECAT_FOCUS_AREA LKCFA ORDER BY FOCUS_AREA_NAME"; if (Session["RoleID"].ToString() == "1" || ((Session["WorkID"].ToString() != "9") || (Session["WorkID2"].ToString() != "9") || (Session["WorkID3"].ToString() != "9"))) { try { myConnection.Open(); OleDbCommand myCommandFocusArea = new OleDbCommand(selectQuery, myConnection); OleDbDataAdapter myAdapter = new OleDbDataAdapter(myCommandFocusArea); DataSet ds = new DataSet(); myAdapter.Fill(ds); dgFocusAreaDetails.DataSource = ds; dgFocusAreaDetails.ShowHeader = true; dgFocusAreaDetails.DataBind(); } catch (Exception exc) { ExceptionLogger.LogException(exc); } finally { if (myConnection != null) { myConnection.Close(); } } } } protected void dgFocusAreaDetails_SelectedIndexChanged(object sender, EventArgs e) { string selectedCategory = dgFocusAreaDetails.SelectedRow.Cells[1].Text; int index = dgFocusAreaDetails.SelectedIndex; lblError.Text = dgFocusAreaDetails.DataKeys[index].Value.ToString(); } public void OnCheckChangedEvent(object sender, EventArgs e) { CheckBox chk = (CheckBox)sender; string chkfocusarea = ((Control)chk).ID; //string focusAreaDetails = dgFocusAreaDetails.SelectedRow.Cells[0].Text; int index =Convert.ToInt32(dgFocusAreaDetails.SelectedIndex); if (chk.Checked) { string updateQuery = "UPDATE [LK_CODECAT_FOCUS_AREA] SET [IS_CURRENT_FOCUS] = 1 WHERE PK_ID = " +Convert.ToInt32( dgFocusAreaDetails.DataKeys[index].Value)+" "; } else { lblError.Text = "unchecked"; } } i want to know how i find the datakeyvalue on checked event.

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• Best way to model Customer <--> Address

  - by Jen

  Every Customer has a physical address and an optional mailing address. What is your preferred way to model this? Option 1. Customer has foreign key to Address Customer (id, phys_address_id, mail_address_id) Address (id, street, city, etc.) Option 2. Customer has one-to-many relationship to Address, which contains a field to describe the address type Customer (id) Address (id, customer_id, address_type, street, city, etc.) Option 3. Address information is de-normalized and stored in Customer Customer (id, phys_street, phys_city, etc. mail_street, mail_city, etc.) One of my overriding goals is to simplify the object-relational mappings, so I'm leaning towards the first approach. What are your thoughts?

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• jQuery select number of tags

  - by ninumedia

  I have multiple comment ids I want to reset to a default value. Ex: <a id="comments_inner_toggle_45">example 1</a> <a id="comments_inner_toggle_608">example 2</a> <a id="comments_inner_toggle_28">example 3</a> ... How can I write the correct tag in jQuery to select every tag with an id of "comments_inner_toggle_" and perform some operation on it? I think it's something similar to: $('a[id|=comments_inner_toggle_]').whatever This is wrong however because the code above will only match the tag with "comments_inner_toggle_" and not with a number appended at the end. How can I fix this? thanks for the help! :)

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• Add database to plesk domain account via XML

  - by Ryan French

  Hi All, I'm currently working on trying to integrate a site with Plesk via the XML API and I've run into a bit of an issue. I've managed to get most things working but I'm trying to add a database to a domain and I keep getting an error. When creating the database I extract a list of Domain Accounts associated with the current clients account, and use the domain guid that is returned in the XML to try and create the new database, but Plesk is returning an error stating that the id I am using is not a valid id. I've looked at the documentation and it is saying that the domain ID that I should be sending is an integer, but the only ID I can find for the domain is the guid, which is a string. Anyone done anything like this before and know where I can get the ID from?

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• PHP - How to retrieve session in php

  - by Klaus Jasper

  I created a table that contains id - names - jobs and page that shows the names only and beside each name there is button Job and session that contains the id. this is my code $query = mysql_query("SELECT * FROM table"); while($fetch = mysql_fetch_array("$query")){ $name = $fetch['names']; $id = $fetch['id']; echo '</br>'; echo $name; $_SESSION['name'] = $id; echo "<button>Job</button>"; } I want when the user click on button Job redirect to a page that contains the job of that session. so how can I do it?

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• Can XPath concatenate two nodeset values? (for use in XForms)

  - by iHeartGreek

  Hi! I am wanting to concatenate two nodeset values using XPath in XForms. I know that XPath has a concat(string, string) function, but how would I go about concatenating two nodeset values? BEGIN EDIT: I tried concat function.. I tried this.. and variations of it to make it work, but it doesn't <xf:value ref="concat(instance('param_choices')/choice/root, .)"/> END EDIT Below is a simplified code example of what I am trying to achieve. XForms model: <xf:instance id="param_choices" xmlns=""> <choices> <root label="Param Choices">/param</root> <choice label="Name">/@AAA</choice> <choice label="Value">/@BBB</choice> </choices> </xf:instance> XForms ui code that I currently have: <xf:select ref="instance('criteria_data')/criteria/criterion" appearance="full"> <xf:label>Param choices:</xf:label> <br/> <xf:itemset nodeset="instance('param_choices')/choice"> <xf:label ref="@label"></xf:label> <xf:value ref="."></xf:value> </xf:itemset> </xf:select> (if user selects "Name" checkbox..) the XML output is: <criterion>/@BBB</criterion> However! I want to combine the root nodeset value with the current choice nodeset value. Essentially: <xf:value ref="(instance('definition_choices')/choice/root) + ."/> to achieve the following XML output: <criterion>/param/@BBB</criterion> Any suggestions on how to do this? (I am fairly new to XPath and XForms) p.s. what I am asking makes sense to me when I typed it out, but if you have trouble figuring out what I'm asking, just let me know.. thanks!

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• SQLiteOpenHelper getWritableDatabse() fails with no Exception

  - by Michal K

  I have a very strange problem. It only shows from time to time, on several devices. Can't seem to reproduce it when I want, but had it so many times, that I think I know where I get it. So I have a Loader which connects to sqlite through a singleton SQLiteOpenHelper: try{ Log.i(TAG, "Get details offline / db helper: "+DatabaseHelper.getInstance(getContext())); SQLiteDatabase db=DatabaseHelper.getInstance(this.getContext()).getWritableDatabase(); Log.i(TAG, "Get details offline / db: "+db); //doing some work on the db //... } catch(SQLiteException e){ e.printStackTrace(); return null; } catch(Exception e){ e.printStackTrace(); return null; //trying everything to grab some exception or whatever } My SQLIteOpenHelper looks something like this: public class DatabaseHelper extends SQLiteOpenHelper { private static DatabaseHelper mInstance = null; private static Context mCxt; public static DatabaseHelper getInstance(Context cxt) { //using app context ass suggested by CommonsWare Log.i("DBHELPER1", "cxt"+mCxt+" / instance: "+mInstance); if (mInstance == null) { mInstance = new DatabaseHelper(cxt.getApplicationContext()); } Log.i("DBHELPER2", "cxt"+mCxt+" / instance: "+mInstance); mCxt = cxt; return mInstance; } //private constructor private DatabaseHelper(Context context) { super(context, DATABASE_NAME, null, DATABASE_VERSION); this.mCxt = context; } @Override public void onCreate(SQLiteDatabase db) { //some tables created here } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { //upgrade code here } It really works great in most cases. But from time to time I get a log similar to this: 06-10 23:49:59.621: I/DBHELPER1(26499): cxtcom.bananout.Bananout@407152c8 / instance: com.bananout.helpers.DatabaseHelper@40827560 06-10 23:49:59.631: I/DBHELPER2(26499): cxtcom.bananout.Bananout@407152c8 / instance: com.bananout.helpers.DatabaseHelper@40827560 06-10 23:49:59.631: I/DetailsLoader(26499): Get event details offline / db helper: com.bananout.helpers.DatabaseHelper@40827560 06-10 23:49:59.631: I/DBHELPER1(26499): cxtcom.bananout.Bananout@407152c8 / instance: com.bananout.helpers.DatabaseHelper@40827560 06-10 23:49:59.651: I/DBHELPER2(26499): cxtcom.bananout.Bananout@407152c8 / instance: com.bananout.helpers.DatabaseHelper@40827560 This line Log.i(TAG, "Get details offline / db: "+db); never gets called! No Exceptions, silence. Plus, the thread with the Loader is not running anymore. So nothing past this line SQLiteDatabase db=DatabaseHelper.getInstance(this.getContext()).getWritableDatabase(); gets executed. What can possibly go wrong on this line?

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• How to synchronize static method in java.

  - by Summer_More_More_Tea

  Hi there: I come up with this question when implementing singleton pattern in Java. Even though the example listed blow is not my real code, yet very similar to the original one. public class ConnectionFactory{ private static ConnectionFactory instance; public static synchronized ConnectionFactory getInstance(){ if( instance == null ){ instance = new ConnectionFactory(); } return instance; } private ConnectionFactory(){ // private constructor implementation } } Because I'm not quite sure about the behavior of a static synchronized method, I get some suggestion from google -- do not have (or as less as possible) multiple static synchronized methods in the same class. I guess when implementing static synchronized method, a lock belongs to Class object is used so that multiple static synchronized methods may degrade performance of the system. Am I right? or JVM use other mechanism to implement static synchronized method? What's the best practice if I have to implement multiple static synchronized methods in a class? Thank you all! Kind regards!

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• Problems inserting file data into sqlite database using python

  - by tylerc230

  I'm trying to open an image file in python and add that data to an sqlite table. I created the table using: "CREATE TABLE "images" ("id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL , "description" VARCHAR, "image" BLOB );" I am trying to add the image to the db using: imageFile = open(imageName, 'rb') b = sqlite3.Binary(imageFile.read()) targetCursor.execute("INSERT INTO images (image) values(?)", (b,)) targetCursor.execute("SELECT id from images") for id in targetCursor: imageid= id[0] targetCursor.execute("INSERT INTO %s (questionID,imageID) values(?,?)" % table, (questionId, imageid)) When I print the value of 'b' it looks like binary data but when I call: 'select image from images where id = 1' I get '????' printed to the console. Anyone know what I'm doing wrong?

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• Override generic methods in c#

  - by Pascal

  I thought I can not override generic methods of a derived class. http://my.safaribooksonline.com/book/programming/csharp/9780071741163/generics/ch18lev1sec13 The code in this link runs fine. The overriden method is called although the instance type of the base class is used and not the instance of the derived type. Now I am confused because a former question of mine Type parameter declaration must be identifier not a type is about calling the overriding generic method with the instance of base type which did NOT work!

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• MySQL: 4 Table "has-many-through" Join?

  - by Nebs

  Let's say I have the following 4 tables (for examples' sake): Owners, Trucks, Boxes, Apples. An owner can have many trucks, a truck can have many boxes and a box can have many apples. Owners have an id. Trucks have an id and owner_id. Boxes have an id and truck_id. Apples have an id and box_id. Let's say I want to get all the apples "owned" by an owner with id = 34. So I want to get all the boxes that are in boxes that are in trucks that owner 34 owns. There is a "hierarchy" if you will of 4 tables that each only has reference to its direct "parent". How can I quickly filter boxes while satisfying conditions across the other 3 tables? I hope that made sense somewhat. Thanks.

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• when to make a method static

  - by Don

  Hi, I'd like to know how people decide whether to define a method as static. I'm aware that a method can only be defined as static if it doesn't require access to instance fields. So lets say we have a method that does not access instance fields, do you always define such a method as static, or only if you need to call it statically (without a reference to an instance). Perhaps another way of asking the same question, is whether you use static or non-static as the default? Thanks, Don

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• Best datastructure for this relationship...

  - by Travis

  I have a question about database 'style'. I need a method of storing user accounts. Some users "own" other user accounts (sub-accounts). However not all user accounts are owned, just some. Is it best to represent this using a table structure like so... TABLE accounts ( ID ownerID -> ID name ) ...even though there will be some NULL values in the ownerID column for accounts that do not have an owner. Or would it be stylistically preferable to have two tables, like so. TABLE accounts ( ID name ) TABLE ownedAccounts ( accountID -> accounts(ID) ownerID -> accounts(ID) ) Thanks for the advice.

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• Insert using strored procedure from nhibernate

  - by jcreddy

  Hi I am using the following code snippets to insert values using stored procedure. the code is executing successfully but no record is inserted in DB. Please suggest with simple example. **---- stored procedure--------** Create PROCEDURE [dbo].[SampleInsert] @id int, @name varchar(50) AS BEGIN insert into test (id, name) values (@id, @name); END **------.hbm file-------** <?xml version="1.0" encoding="utf-8" ?> <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"> <sql-query name="Procedure"> exec SampleInsert :Id,:Name </sql-query> </hibernate-mapping> **--------c# code to insert value using above sp------** ISessionFactory sessionFactory = new Configuration().Configure().BuildSessionFactory(); ISession session = sessionFactory.OpenSession(); IQuery query = session.GetNamedQuery("Procedure"); query.SetParameter("Id", "222"); query.SetParameter("Name", "testsp"); query.SetResultTransformer(new NHibernate.Transform.AliasToBeanConstructorResultTransformer(typeof(Procedure).GetConstructors()[0])); Regards Jcreddy

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• Segmentation fault before return

  - by donalmg

  Hi, Why does the following code seg fault before returning: int main() { char iD[20]; memset (iD, 0, 20); char* prefix; srand (time(NULL) ); int iPrefix = rand()%1000000; sprintf(prefix, "%i", iPrefix); int len = strlen(prefix); char* staticChar = "123456789"; //set prefix into ID memcpy(iD, prefix, len); // append static value memcpy(iD+len, staticChar, 20-len); cout << "END " << endl; return 0; } At the minute, the cout will display, but I get a segmentation fault.

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• How to refresh site if $_SESSION variable has changed

  - by 4ndro1d

  I'm writing in my $_SESSION variable from a database, when i clicked a link. public function getProjectById($id){ $query="SELECT * FROM projects WHERE id=\"$id\""; $result=mysql_query($query); $num=mysql_numrows($result); while ($row = mysql_fetch_object($result)) { $_SESSION['projectid'] = $row->id; $_SESSION['projecttitle'] = $row->title; $_SESSION['projectinfo'] = $row->info; $_SESSION['projecttext'] = $row->text; $_SESSION['projectcategory'] = $row->category; } } Now my variable is overwritten and I want to show these variables in my index.php like this: <div id="textContent"> <?php if(isset($_SESSION['projecttext']) && !empty($_SESSION['projecttext'])) { echo $_SESSION['projecttext']; }else { echo 'No text'; } ?></div> But of course, my page will not refresh automatically. How can I do that?

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• Who needs singletons?

  - by sexyprout

  Imagine you access your MySQL database via PDO. You got some functions, and in these functions, you need to access the database. The first thing I thought of is global, like: $db = new PDO('mysql:host=127.0.0.1;dbname=toto', 'root', 'pwd'); function some_function() { global $db; $db->query('...'); } But it's considered as a bad practice. So, after a little search, I ended up with the Singleton pattern, which "applies to situations in which there needs to be a single instance of a class." According to the example of the manual, we should do this: class Database { private static $instance, $db; private function __construct(){} static function singleton() { if(!isset(self::$instance)) self::$instance = new __CLASS__; return self:$instance; } function get() { if(!isset(self::$db)) self::$db = new PDO('mysql:host=127.0.0.1;dbname=toto', 'user', 'pwd') return self::$db; } } function some_function() { $db = Database::singleton(); $db->get()->query('...'); } some_function(); But I just can't understand why you need that big class when you can do it merely with: class Database { private static $db; private function __construct(){} static function get() { if(!isset(self::$rand)) self::$db = new PDO('mysql:host=127.0.0.1;dbname=toto', 'user', 'pwd'); return self::$db; } } function some_function() { Database::get()->query('...'); } some_function(); This last one works perfectly and I don't need to worry about $db anymore. But maybe I'm forgetting something. So, who's wrong, who's right?

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