How can we get the lsit of column names form the table

[Manju Nath，修改在8 年前。]

I am trying to get the list of column names from the table. (Let's say table name is: USER_).

<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%>
<%@ taglib uri="http://java.sun.com/portlet_2_0" prefix="portlet" %>
<%@ taglib uri="http://liferay.com/tld/aui" prefix="aui" %>
<%@ taglib uri="http://liferay.com/tld/portlet" prefix="liferay-portlet" %>
<%@ taglib uri="http://liferay.com/tld/theme" prefix="liferay-theme" %>
<%@ page import="com.liferay.portal.service.ClassNameLocalServiceUtil" %>
<%@page import="java.util.ArrayList" %>
<portlet:defineobjects />
<theme:defineobjects />
    &lt;%
    long userClassNameId = ClassNameLocalServiceUtil.getClassNameId("com.liferay.portal.model.User");
    List<user> columns =  
// How can I fetch the list of column names in to columns list ?
    %&gt;</user>

Is there any predefined methods to get the list of columns OR any other simplest way to achieve the same?

[Tina Agrawal，修改在8 年前。]

You can use http://docs.oracle.com/javase/7/docs/api/java/lang/Class.html#getDeclaredFields()

Tina

[Manju Nath，修改在8 年前。]

Can you please elaborate the answer. I didn't get solution from your suggestion.
Thank you

[Tina Agrawal，修改在8 年前。]

Try this -

User.class.getDeclaredFields()
And then iterate the fields and check.


Tina

[Manju Nath，修改在8 年前。]

I tried that, but the field list contains null. No columns are retrieved. Any suggestion please

[Ravi Kumar Gupta，修改在8 年前。]

Try this. This will list all the tables and columns.

try {
		        DataSource dataSource = (DataSource) PortalBeanLocatorUtil.locate("liferayDataSource");
		        Connection connection =  dataSource.getConnection();
		        DatabaseMetaData md = connection.getMetaData();
		        ResultSet rs = md.getTables(null, null, "%", null);
		        while (rs.next()) {
		        	System.out.println("Table : "+rs.getString(3));
		        	
		        	ResultSet cols = md.getColumns(null, null, rs.getString(3), null);
		        	while(cols.next()){
		        		System.out.println("\tCol: - " + cols.getString(4));
		        	}
		        }
		  
		    } catch (SQLException e) {
		    	LOGGER.error("SQLException: "+ e.getMessage());
		    }

Imports will be

import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.ResultSet;
import java.sql.SQLException;

[Manju Nath，修改在8 年前。]

From where can I import the Datasource? I am getting an error "DataSource cannot be resolved a type". Any suggestion?

[Ravi Kumar Gupta，修改在8 年前。]

import javax.sql.DataSource;

[Manju Nath，修改在8 年前。]

Able to fetch the all the tables with respective columns. Thank you so much

[Manju Nath，修改在8 年前。]

I have a weird problem, If I print a column names in the console the column names are showing fine. But If I print the column names in the web page the column names of each character is separating with hi-fen (-) as attached in the screenshot.

My Code is :

<liferay-portlet:actionurl portletConfiguration="true" var="configurationURL" />
<aui:form action="<%= configurationURL %>" method="post" name="fm">
&lt;%
ArrayList<string> al = new ArrayList<string>();
try {
    DataSource dataSource = (DataSource) PortalBeanLocatorUtil.locate("liferayDataSource");
    Connection connection =  dataSource.getConnection();
    DatabaseMetaData md = connection.getMetaData();
    ResultSet rs = md.getTables(null, null, "%", null);
    while (rs.next()) {
       System.out.println("Table : "+rs.getString(3));
       String tableVal = rs.getString(3);
       if(tableVal.equalsIgnoreCase("USER_"))
       {
    	   ResultSet cols = md.getColumns(null, null, rs.getString(3), null);
           while(cols.next()){
               System.out.println("\tCol: - " + cols.getString(4));
               String str = cols.getString(4);
           	   al.add(str);
           }  
       }
   }
} catch (SQLException e) {
	System.out.println("SQLException: "+ e.getMessage());
}

Iterator<string> itr = al.iterator();
while(itr.hasNext())
{
	%&gt;
		<aui:input name="<%= itr.next() %>" type="checkbox" />
	&lt;%
}

%&gt;
	 <aui:button-row>
         <aui:button type="submit" />
      </aui:button-row>
</string></string></string></aui:form>

What 's wrong in my code? And why is it showing differently on UI than console?

[Ravi Kumar Gupta，修改在8 年前。]

That's weird.. I could get it without hyphen.. Check if some javascript doing something like this.. or there can be some other reason..

[Manju Nath，修改在8 年前。]

I haven't used any javascript. I used only the code which you provide me. Nothing extra in it. I tried multiple ways to display it properly but it is not happening. Please suggest some solution

[Ravi Kumar Gupta，修改在8 年前。]

Try the same code on a vanilla liferay.

[Manju Nath，修改在8 年前。]

Got the issue. All the characters are in the string are in upper case so for the same reason it is showing like that on UI. I have converted the string in to lowercase Now it seems to be fine on UI.

Thank you