dr-jts / jeql

A SQL-esque scripting language for spatial processing and ETL

JEQL

JEQL is a scripting language for spatial processing and ETL, which runs on the JVM.

JEQL is based on the standard, well-known SQL model.
This provides powerful declarative specification of data querying and transformation.

SQL support

JEQL improves on SQL syntax & semantics by adding:

• a streaming model of computation
• factoring complex SQL queries into a chain of simpler queries
• defining named expressions for SELECT lists
• providing SPLIT BY as the the inverse of GROUP BY

Functions and Commands

JEQL provides an extensive set of commands and functions.

Built-in commands include:

• Readers and Writers for many textual and spatial formats
• Readers and Writers for JDBC databases
• A Reader supporting Postgres/PostGIS native spatial datatypes

Built-in function libraries include:

• Geometry manipulation
• String manipulation
• RegEx matching and extracting

and many others...

Extensibility

JEQL is easily extensible, using the dynamic loading and reflection capabilities of the JVM.

• Functions are Java static methods
• Commands are Java classes implementing a simple interface

Tools

JEQL provides the following tools:

• A command-line script runner
• A Workbench GUI
  • Edit, run and debug scripts
  • View script data tables
  • View spatial data