Databases
StackOverflow2013
Postsdbo
POFill drop down box with values from a class
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POFill drop down box with values from a class
    primarykey
    data
    text
    <p>i have this as JSP page and i want a combobox to fill up the values from a table in the database. I have a class Assembly and a Class Assemblys, in Assemblys i make every record an instance of Assembly and put it in a list. But i can't retrieve it in JSTL? Why is this?</p> <pre><code> &lt;%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%&gt; ..... &lt;select name = "assembly"&gt; &lt;c:forEach var ="item" items="${Assemblys}"&gt; &lt;option value="${item.id}"&gt;${item.Name}&lt;/option&gt; &lt;/c:forEach&gt; &lt;/select&gt; </code></pre> <p>This as the class Assembly Class</p> <pre><code> public class Assembly { public String Name; public int cost; public int id; public Assembly(String Name, int cost, int id) { this.Name = Name; this.cost = cost; this.id = id; } } </code></pre> <p>And this is the class Assemblys</p> <pre><code> public class Assemblys { List&lt;Assembly&gt; list = new ArrayList&lt;Assembly&gt;(); public Assemblys(){ list = getAssemblys(); } private List&lt;Assembly&gt; getAssemblys() { try { Connection conn = MysqlConnect.conn(); PreparedStatement pstmt = null; ResultSet rs = null; String Query = "Select * from tbl_assembly"; pstmt = conn.prepareStatement(Query); rs = pstmt.executeQuery(); while (rs.next()) { Assembly ass = new Assembly(rs.getString(2),rs.getInt(3),rs.getInt(1)); list.add(ass); } conn.close(); } catch (SQLException ex) { Logger.getLogger(Assemblys.class.getName()).log(Level.SEVERE, null, ex); } return list; } } </code></pre> <p>Why is my drop down list blank? I don't get it. I thought this was the right code?</p> <p>Many thanks in advance!</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USShashi
    1. USNick
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POFill drop down box with values from a class
      1. This table or related slice is empty.
      1. VTApproveEditSuggestion
    2. VO
      singulars
      1. POFill drop down box with values from a class
      1. This table or related slice is empty.
      1. VTDownMod
    1. COIn which attribute, you are setting Assemblys in servlet. Please paste the code of servlet...
      singulars
      1. POFill drop down box with values from a class
      1. USShashi
    2. COThere is no servlet, this is not required for this code to work(atleast I thought so)
      singulars
      1. POFill drop down box with values from a class
      1. USNick
    3. COHow did you invoke getAssemblys method of Assemblys class
      singulars
      1. POFill drop down box with values from a class
      1. USShashi
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload