MySQL table and Combobox/TreeTable

Vaadin 6 / 7 / 8 Framework Data Binding
1

Hi, I want to show in a treetable or combobox unique values from a MySQL table.

For example, if in column 1 of the table, I have 3 rows named “A”, and 3 rows named “B”, I would like to show only once “A” and “B”, instead of six different options (that is what I have so far)…

any ideas on how to do it??

thanks!!!

2

any ideas on this???

3

It’s almost impossible to know how to guide you, as I don’t know how you are populating the container behind the combo box - there are many ways to do this.

If you are retrieving just the names in a SQL statement, change the SQL from

SELECT NAME FROM TABLE

to

SELECT DISTINCT NAME FROM TABLE

Other than that, show us the code.

Cheers,

Charles.

4

Hi:

Thank you for your answer… what I have is this:


ComboBox combo1 = new ComboBox("Please select a name");
		combo1.setContainerDataSource(contenedor);
		combo1.setItemCaptionPropertyId("firstName");
		layout.addComponent(combo1);

where “contenedor” is a SQLContainer for a table like the on shown below. As you can see, the name "Juan appears twice and I would like to show it only once. Is it possible?

reagards, and thank you very much
12234.jpg
12235.jpg

5

Hi,

Well, the most important bit of code is the bit you haven’t shown us! How are you creating the container?

I’ve never used SQLContainer myself, so I don’t know exactly how it works. The contents of the container control what appears in the combo box, so you need to limit the contents of the container. A quick look at the source code for SQLContainer suggests that something like the following (untested, probably doesn’t even compile) would do.

Query query = new FreeformQuery("SELECT DISTINCT FIRSTNAME FROM PEOPLE",null, connectionPool);
SQLContainer c = new SQLContainer(query);

If you need to use the same container for two different tables/combo boxes, then this approach wouldn’t work.

Cheers,

Charles.

6

Hi Charles, thank you very much for your answer…here is the rest of the code:

before I populate the combobox, I create the “contenedor” SQLContainer:

Conexion conexion=new Conexion();
		SQLContainer contenedor= conexion.getContainer6_Users();

where Conexion() is:

package com.example.prueba11;

import java.sql.SQLException;
import com.vaadin.addon.sqlcontainer.SQLContainer;
import com.vaadin.addon.sqlcontainer.connection.JDBCConnectionPool;
import com.vaadin.addon.sqlcontainer.connection.SimpleJDBCConnectionPool;
import com.vaadin.addon.sqlcontainer.query.TableQuery;

public class Conexion {
	
	public TableQuery q6;
	private JDBCConnectionPool connectionPool = null;
	private SQLContainer Container6_Users=null;
	
	public Conexion() {
	  	  initConnectionPool();
	  	  initContainers();
	    }
	
	private void initConnectionPool() {
		try {
          	connectionPool=new SimpleJDBCConnectionPool(
                  	"com.mysql.jdbc.Driver",
                  	"jdbc:mysql://localhost:3306/data", "root", "hola", 2, 5);
      	} catch (SQLException e) {
        	  e.printStackTrace();
        }	
	}
	
	public void initContainers()  {
		try{
					
				q6=new TableQuery("users", connectionPool);
				q6.setVersionColumn("VERSION");
				
				Container6_Users=new SQLContainer(q6);
				
			} catch (SQLException e) {
	      	  e.printStackTrace();
	      }
		}

	public SQLContainer getContainer6_Users() {
		return Container6_Users;
	}

	public void setContainer6_Users(SQLContainer container6_Users) {
		Container6_Users = container6_Users;
	}
}

This code works perfect so far, except for the filter distinct for the combobox. For example, to filter in a simple treetable I use:

filter1= new Compare.Equal(que, valor);

which works just fine…

Can you help me out with this?..thank you very much for all your help…

regards,

Hugo