Bug 189100 [Regression]X-axis data column issue[0001]
Description: [Regression]X-axis data column issue[0001] Step: 1.New a sample datasource and dataset from OFFICES 2.New a chart and use the dataset 3.Change the data type of OFFICECODE from string to integer. 4.Drop the column of OFFICECODE to Value(Y)Series. Actual result: Show the error message: Unable to use a text data to render a numerical/datetime axis.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/api/querydefn/BaseQueryDefinition.java
/**
	 * Constructs an instance with parent set to the specified <code>BaseQueryDefinition</code>
	 */
	BaseQueryDefinition( IBaseQueryDefinition parent )
	{
		parentQuery = parent;
	}
	
	/**
	 * Returns the group definitions as an ordered collection of <code>GroupDefinition</code>
	 * objects. Groups are organizations within the data that support
	 * aggregation, filtering and sorting. Reports use groups to trigger
	 * level breaks.
	 * 
	 * @return the list of groups. If no group is defined, null is returned.
	 */
	
	public List getGroups( )
	{
		return groups;
	}
	/**
	 * Appends a group definition to the group list.
	 * @param group Group definition to add
	 */
	public void addGroup( GroupDefinition group )
	{
	    groups.add( group );
	}