This paper aims to show that SQL queries can be used to solve a well-known combinatorial optimization problem, the MAXimum CLIQUE Problem (MAXCLIQUE). This problem arises in many real world applications as computer vision and pattern recognition or coding theory to mention some of them. A clique of a graph is a complete sub-graph, i.e., a graph where every pair of vertices is an edge. The MAXCLIQUE problem searches for the clique of the largest cardinality in a graph (the one with the greatest number of nodes). The authors propose a model based on SQL queries to solve this problem. They test their models in 62 random instances.