Recent research works propose to use the Object-Oriented (OO) approach such as UML to model data warehouses. First, the present paper overviews these recent OO techniques. They aim to describe the facts and the different analysis dimensions of the data. Second, we will propose a tutorial of the Object Constraint Language (OCL) and we will show how this language can be used to specify constraints in OO-based models of data warehouse. Up to now, OCL has been only applied to describe constraints in software applications and transactional databases. So, we demonstrate in this paper how to use OCL to represent the different types of data warehouse constraints. Our paper is addressed to researchers working in the fields of business intelligence and decision support systems, who wish to learn about the major possibilities that OCL offer in the context of data warehouse, and to find citations that will allow them to learn about this formalism in greater detail. We also provide general information about the possible types of implementation of multi-dimensional models and their constraints.