Bug 161191 Null is inserted when drag columns to query text with ctrl key pressed
Description: Null is inserted when drag columns to query text with ctrl key pressed Steps to reproduce: 1. New a data source. 2. New a dataset. 3. Press and hold ctrl key, select OFFICECODE and CITY columns, drag to query text. Expected result: "CLASSICMODELS.OFFICES.OFFICECODE,CLASSICMODELS.OFFICES.CITY" is inserted in query text. Actual result: "null,CLASSICMODELS.OFFICES.OFFICECODE,CLASSICMODELS.OFFICES.CITY" is inserted
data/org.eclipse.birt.report.data.oda.jdbc.ui/src/org/eclipse/birt/report/data/oda/jdbc/ui/editors/SQLDataSetEditorPage.java
* 
	 * @param schemaName
	 * @param tableName
	 * @return
	 */
	private String getTableNameWithSchema( String schemaName,
			String tableName )
	{
		String tableNameWithSchema = tableName;
		if ( schemaName != null && schemaName.trim( ).length( ) > 0 )
		{
			tableNameWithSchema = schemaName + "." + tableName;
		}
		return tableNameWithSchema;
	}
	
	/**
	 * if the schema is not support, populate the table list
	 *
	 */
	protected void populateTableList( )
	{
		if ( rootNode != null )
		{
			removeTreeItem( rootNode );
		}
		ResultSet tablesRs = null;
		ArrayList procedureRs = null;
		String catalogName = metaDataProvider.getCatalog( );
		tableList = new ArrayList( );