Sqawk

Sqawk is an SQL-based command-line tool for processing delimiter-separated files (CSV, TSV, etc.), inspired by the classic awk command. It loads data into in-memory tables, executes SQL queries, and optionally writes results back to files.

Features

• SQL Query Engine - SELECT, INSERT, UPDATE, DELETE with WHERE, ORDER BY, GROUP BY, HAVING, LIMIT/OFFSET
• Joins - INNER, LEFT, RIGHT, FULL OUTER, and CROSS joins with ON conditions
• Aggregates - COUNT, SUM, AVG, MIN, MAX with GROUP BY support
• Functions - String (UPPER, LOWER, SUBSTR, REPLACE, etc.), math (ABS, ROUND, etc.), date/time
• Subqueries - Scalar, IN (SELECT ...), and EXISTS, including correlated
• Set Operations - UNION, UNION ALL, INTERSECT, EXCEPT
• Window Functions - ROW_NUMBER, RANK, DENSE_RANK, LAG, LEAD, and aggregates with OVER (PARTITION BY ... ORDER BY ...)
• DDL - CREATE TABLE, CREATE TABLE AS SELECT, DROP, ALTER TABLE ADD COLUMN, TRUNCATE
• Expressions - CASE, CAST, COALESCE, NULLIF, BETWEEN, IN, LIKE/ILIKE, ||, arithmetic
• File Formats - CSV, TSV, and custom delimiters; headerless files via --tabledef
• Pipelines - Reads standard input with a - file operand
• Safe by Default - Files unchanged unless --write flag is specified
• Interactive REPL - Explore data interactively with -i flag

Installation

cargo install sqawk

This installs two binaries: sqawk and tsq. Requires Rust 1.88 or newer.

Quick Examples

# Query a CSV file
sqawk -s "SELECT name, salary FROM employees WHERE department = 'Engineering'" employees.csv

# Join two files
sqawk -s "SELECT u.name, o.total FROM users u JOIN orders o ON u.id = o.user_id" users.csv orders.csv

# Aggregate data
sqawk -s "SELECT department, AVG(salary) FROM employees GROUP BY department" employees.csv

# Modify and save
sqawk -s "UPDATE data SET status = 'archived' WHERE year < 2020" data.csv --write

# Read standard input as the table "stdin"
cat employees.csv | sqawk -s "SELECT name FROM stdin WHERE salary > 70000" -

tsq - test data generator

cargo install sqawk also installs tsq, which generates deterministic multi-table CSV data plus a corpus of SQL queries for exercising sqawk.

tsq --seed 42 --rows 1000 --output-dir /tmp/sqawk-test
sqawk -s "SELECT * FROM customers LIMIT 10" /tmp/sqawk-test/data/customers.csv

It writes data/ (customers, products, orders, order_items, reviews, with realistic foreign-key relationships), queries/ (numbered .sql files covering selects, joins, aggregates, subqueries and window functions), verify/run_verification.sh, and a metadata.json recording the seed and row counts. The same seed always produces the same data.

Documentation

• User Guide - Installation, CLI options, and examples
• SQL Reference - Complete SQL syntax and functions
• Database Architecture - Technical internals (for contributors)

License

MIT License - see LICENSE

Contributing

Contributions welcome. Any contribution submitted for inclusion shall be licensed as MIT.