Abstract: The problem of the translation and compatibility of high level data base query languages is addressed via a case study of the languages SEQUEL and Query by Example. In particular, an algorithm for translating queries on a relational data base stated in Query by Example into queries expressed in SEQUEL is introduced. This algorithm is used as a vehicle to describe a consistent interpretation of the semantics of SEQUEL and Query by Example. The compatibility of Query by Example and SEQUEL is briefly discussed. Examples of the operation of the algorithm are presented.