The SQL Linter for Humans

SQLFluff is a dialect-flexible and configurable SQL linter. Designed with ELT applications in mind, SQLFluff also works with Jinja templating and dbt. SQLFluff will auto-fix most linting errors, allowing you to focus your time on what matters.

Dialects Supported

Although SQL is reasonably consistent in its implementations, there are several different dialects available with variations of syntax and grammar. SQLFluff currently supports the following SQL dialects (though perhaps not in full):

ANSI SQL - this is the base version and on occasion may not strictly follow the ANSI/ISO SQL definition
Athena
BigQuery
ClickHouse
Databricks (note: currently this is just an alias for the sparksql dialect).
Db2
DuckDB
Exasol
Hive
Materialize
MySQL
Oracle
PostgreSQL (aka Postgres)
Redshift
Snowflake
SOQL
SparkSQL
SQLite
Teradata
Transact-SQL (aka T-SQL)

We aim to make it easy to expand on the support of these dialects and also add other, currently unsupported, dialects. Please raise issues (or upvote any existing issues) to let us know of demand for missing support.

Pull requests from those that know the missing syntax or dialects are especially welcomed and are the question way for you to get support added. We are happy to work with any potential contributors on this to help them add this support. Please raise an issue first for any large feature change to ensure it is a good fit for this project before spending time on this work.

Templates Supported

SQL itself does not lend itself well to modularity, so to introduce some flexibility and reusability it is often templated as discussed more in our modularity documentation.

SQLFluff supports the following templates:

Jinja (aka Jinja2)
dbt

Again, please raise issues if you wish to support more templating languages/syntaxes.

Getting Started

To get started, install the package and run sqlfluff lint or sqlfluff fix.

$ pip install sqlfluff
$ echo "  SELECT a  +  b FROM tbl;  " > test.sql
$ sqlfluff lint test.sql --dialect ansi
== [test.sql] FAIL
L:   1 | P:   1 | L050 | Files must not begin with newlines or whitespace.
L:   1 | P:   3 | L003 | First line has unexpected indent
L:   1 | P:  11 | L039 | Unnecessary whitespace found.
L:   1 | P:  14 | L039 | Unnecessary whitespace found.
L:   1 | P:  27 | L001 | Unnecessary trailing whitespace.

Alternatively, you can use the Official SQLFluff Docker Image or have a play using SQLFluff online.

For full CLI usage and rules reference, see the SQLFluff docs.

Documentation

For full documentation visit docs.sqlfluff.com. This documentation is generated from this repository so please raise issues or pull requests for any additions, corrections, or clarifications.

Releases

SQLFluff adheres to Semantic Versioning, so breaking changes should be restricted to major versions releases. Some elements (such as the python API) are in a less stable state and may see more significant changes more often. See the changelog for more details. If you would like to join in please consider contributing.

New releases are made monthly. For more information, visit Releases.

SQLFluff on Slack

We have a fast-growing community on Slack, come and join us!

SQLFluff on Twitter

Contributing

We are grateful to all our contributors. There is a lot to do in this project, and we are just getting started.

If you want to understand more about the architecture of SQLFluff, you can find more here.

If you would like to contribute, check out the open issues on GitHub. You can also see the guide to contributing.

John-Schreiber/sqlfluff