PRQL is a modern language for transforming data — a simple, powerful, pipelined SQL replacement
Pipelined Relational Query Language, pronounced "Prequel".
PRQL is a modern language for transforming data — a simple, powerful, pipelined SQL replacement. Like SQL, it's readable, explicit and declarative. Unlike SQL, it forms a logical pipeline of transformations, and supports abstractions such as variables and functions. It can be used with any database that uses SQL, since it compiles to SQL.
PRQL can be as simple as:
from tracks
filter artist == "Bob Marley" # Each line transforms the previous result
aggregate { # `aggregate` reduces each column to a value
plays = sum plays,
longest = max length,
shortest = min length, # Trailing commas are allowed
}
Here's a fuller example of the language;
from employees
filter start_date > @2021-01-01 # Clear date syntax
derive { # `derive` adds columns / variables
gross_salary = salary + (tax ?? 0), # Terse coalesce
gross_cost = gross_salary + benefits_cost, # Variables can use other variables
}
filter gross_cost > 0
group {title, country} ( # `group` runs a pipeline over each group
aggregate { # `aggregate` reduces each group to a value
average gross_salary,
sum_gross_cost = sum gross_cost, # `=` sets a column name
}
)
filter sum_gross_cost > 100_000 # `filter` replaces both of SQL's `WHERE` & `HAVING`
derive id = f"{title}_{country}" # F-strings like Python
derive country_code = s"LEFT(country, 2)" # S-strings allow using SQL as an escape hatch
sort {sum_gross_cost, -country} # `-country` means descending order
take 1..20 # Range expressions (also valid here as `take 20`)
For more on the language, more examples & comparisons with SQL, visit prql-lang.org. To experiment with PRQL in the browser, check out PRQL Playground.
PRQL is being actively developed by a growing community. It's ready to use by the intrepid, either with our supported integrations, or within your own tools, using one of our supported language bindings.
PRQL still has some bugs and some missing features, and is probably only ready to be rolled out to non-technical teams for fairly simple queries.
In particular, we're working on a new resolver, which will let us squash many bugs and simplify our code a lot. It'll also let us scale the language without scaling the complexity of the compiler.
While we work on that, we're also focusing on
We're also spending time thinking about:
window
transform.To stay in touch with PRQL:
This repo is composed of:
It also contains our testing / CI infrastructure and development tools. Check out our development docs for more details.
Many thanks to those who've made our progress possible: