This study investigated mutation testing for graph database queries. Database queries serve a significant role in many application programs. SQL queries are the most common, but new types of databases and their query languages have emerged and begun gaining popularity. This paper focuses on queries written in Cypher, a language for accessing graph databases. Several mutation operators are proposed, and a tool for generating mutant Cypher queries from a given query is presented.

We study the applicability of graph queries to the coverage analysis of test cases for requirements specifications.First we show that when the similarity degrees between requirements specifications and test cases are available, they can be represented in the form of a graph.Then we identify several queries that are useful for extracting coverage information and show that all these queries can be written in the Cypher query language, a common graph query language.In a case study we apply these queries to data obtained from a real-world project in industry.The results of the case study show that coverage information can be retrieved in reasonable time.We also compare the graph queries with SQL queries with respect to conciseness and processing time.