Bug 207120 Please model provide an API for data type conversion.
Currently, there're two data types: column data type and parameter data type. But they're inconsistent. Could model provide APIs for conversion between the two types. Thanks. In addition: please check the code into head and 2.2.1 branch, because we have a 2.2.1 bug to fix.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/util/DataTypeConversionUtil.java
*/
	public static String converToParamType( String columnType )
	{
		if ( StringUtil.isBlank( columnType ) )
			return null;
		if ( DesignChoiceConstants.COLUMN_DATA_TYPE_ANY.equals( columnType ) )
			return DesignChoiceConstants.PARAM_TYPE_ANY;
		if ( DesignChoiceConstants.COLUMN_DATA_TYPE_BOOLEAN.equals( columnType ) )
			return DesignChoiceConstants.PARAM_TYPE_BOOLEAN;
		if ( DesignChoiceConstants.COLUMN_DATA_TYPE_DATETIME
				.equals( columnType ) )
			return DesignChoiceConstants.PARAM_TYPE_DATETIME;
		if ( DesignChoiceConstants.COLUMN_DATA_TYPE_DATE.equals( columnType ) )
			return DesignChoiceConstants.PARAM_TYPE_DATE;
		if ( DesignChoiceConstants.COLUMN_DATA_TYPE_TIME.equals( columnType ) )
			return DesignChoiceConstants.PARAM_TYPE_TIME;
		if ( DesignChoiceConstants.COLUMN_DATA_TYPE_DECIMAL.equals( columnType ) )
			return DesignChoiceConstants.PARAM_TYPE_DECIMAL;
		if ( DesignChoiceConstants.COLUMN_DATA_TYPE_FLOAT.equals( columnType ) )
			return DesignChoiceConstants.PARAM_TYPE_FLOAT;
		if ( DesignChoiceConstants.COLUMN_DATA_TYPE_INTEGER.equals( columnType ) )
			return DesignChoiceConstants.PARAM_TYPE_INTEGER;
		if ( DesignChoiceConstants.COLUMN_DATA_TYPE_STRING.equals( columnType ) )
			return DesignChoiceConstants.PARAM_TYPE_STRING;
		return columnType;
	}
	/**
	 * Returns the corresponding column data type choice with the given
	 * parameter type.
	 *