Learning QL

QL is Semmle’s query language. You can use queries written in QL to explore code and quickly find security vulnerabilities and bugs.

QL queries are easy to write and share–visit the topics below and our open source repository on GitHub to learn more.

You can also try out QL in the query console on LGTM.com. Here, you can write QL code to query open source projects directly, without having to download snapshots and libraries.

Getting started

If you are new to QL, start by looking at the following topics:

If you are a complete beginner, get started by working through the QL detective tutorials.

Writing QL queries

To learn more about writing your own queries, see Writing QL queries.

For more information on writing QL to query code written in a specific language see:

Technical information

For more technical information see:

Reference topics

For a more comprehensive guide to QL see the following reference topics: