6 Property Graph Query Language (PGQL)

PGQL is a SQL-like query language for property graph data structures that consist of vertices that are connected to other vertices by edges, each of which can have key-value pairs (properties) associated with them.

The language is based on the concept of graph pattern matching, which allows you to specify patterns that are matched against vertices and edges in a data graph.

Note:

The graph server (PGX) 22.4.0 supports PGQL 1.5 and earlier versions.

The property graph support provides two ways to execute Property Graph Query Language (PGQL) queries through Java APIs:

• Use the oracle.pgx.api Java package to query an in-memory snapshot of a graph that has been loaded into the graph server (PGX), as described in Using the Graph Server (PGX).

• Use the oracle.pg.rdbms.pgql Java package to directly query graph data stored in Oracle Database, as described in Executing PGQL Queries Against Property Graph Schema Tables.

For more information about PGQL, see the PGQL Specification.

• Creating a Property Graph Using PGQL
  
• Pattern Matching with PGQL
  
• Edge Patterns Have a Direction with PGQL
  
• Vertex and Edge Labels with PGQL
  
• Variable-Length Paths with PGQL
  
• Aggregation and Sorting with PGQL
  
• Supported PGQL Features and Limitations
  
• Executing PGQL Queries Against the Graph Server (PGX)
  This section describes the Java APIs that are used to execute PGQL queries in the graph server (PGX).
• Executing PGQL Queries Directly Against Oracle Database
  This topic explains how you can execute PGQL queries directly against the graph in Oracle Database (as opposed to the graph loaded into the graph server (PGX)).