Visual Query Language for Graph Databases

A graph database is a non-relational database that uses graph structures with vertices, edges, and properties associated to both of them to represent and store data. Graph databases are a powerful tool for graph-like queries: a query consists of vertices and edges with specified relations between their attributes, the result will be the collection of all subgraphs matching the specified pattern, or a graph-theory metric computed on top of this collection. 
How can we visually support the formulation of queries for a graph database?

The candidate, according to the assigned scope (PR/Bak/DA, see table below), has to perform the following activities: 

State-of-The-Art Report: write an annotated survey of existing graph databases, graph query languages and in particular visual query languages for graph databases. 

Basic features: given a specific graph database (DB)  implementation and a specific query language, develop a visual query language enabling the user to draw queries in terms of edges-vertices-attributes patterns. 

Advanced features: some graph DB implementations allow for the specification of consistency constraints by defining a schema (similarly to relational DBs); the aim is to provide visual support for the definition of the schema. In alternative/addition, visual support will be added to specify complex queries having graph-theory metrics as their results.  

Scientific summary: summarize the scientific contribution of the work, with reflections on the lesson learned and future advancement in this research field.  

  Seminar Project Bachelor Master
Writing State-of-The-Art Report    
Coding basic features  
Designing/coding adv. features    
Writing scientific summary    


information visualization, graph visualization, graph databases
Other information: 

Graph DB implementation(s)neo4j, ...

Graph query language(s)Gremlin, ...

Visual programmin toolkits/libraries: Blockly, ...

Visualization toolkits/librariesD3.js, ...

Further reading: J. Mauerer, “A Visual Query Language for Graph Databases”, Master Thesis, TU Wien, 2015

Previous knowledge: 
information visualization, java/javascript
Albert Amor-Amorós, by appointment, amor [at]
Information Visualization (IV)
in progress