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
if ( schemaName != null
								&& schemaName.trim( ).length( ) > 0 )
						{
							fullyQualifiedTableName = schemaName + "." + "STORED PROCEDURES";
						}
						DbObject dbObject = new DbObject( fullyQualifiedTableName,"STORED PROCEDURES", DbObject.PROCEDURE_TYPE, tableImage);
						tableList.add( dbObject );
					}
					if ( schemaTreeItem != null ) 
					{
						TreeItem item[] = Utility.createTreeItems( schemaTreeItem,
								tableList,
								SWT.NONE,
								null );
						
						if ( expandDbObjectsTree && item != null && item.length > 0 )
						{
							availableDbObjectsTree.showItem( item[0] );
						}
					}
				}
				catch(SQLException e)
				{
					e.printStackTrace();
				}
			}
		}
	}
	
	/**