Paper Title
Implementing Check Integrity Constraint in Graph Databases

Abstract
The issue of maintaining a database in a consistent state is becoming more challenging in situations where users are able to store differentkinds of data in the database without any control. Leaving this process unattended can lead to invalid and duplicate data in the database, which can directly affect the correctness of gathered data. In this paper, an overview of integrity constraints is given with the emphasis on graph databases, as well as the level of support provided by Neo4j, the most popular graph database management system (DBMS).A new integrity constraint, which prevents users from entering data with values outside the permitted predefined set of values, is also presented and elaborated. Keywords� Integrity constraints, CHECK, Gremlin, Neo4j, Graph databases.