SQLens

A multi-dialect SQL parser and analyzer written in Go. Parses queries into an AST, extracts metadata, suggests optimizations, validates against schemas, and monitors SQL log files in real time.

Installation

With Nix:

nix run github:Chahine-tech/sql-parser-go -- --help
nix develop   # development environment

From source (requires Go 1.21+):

git clone https://github.com/Chahine-tech/sql-parser-go.git
cd sql-parser-go
make build

Usage

# Analyze a query file
./bin/sqlparser -query examples/queries/complex_query.sql -output table

# Analyze an inline query
./bin/sqlparser -sql "SELECT * FROM users WHERE id > 100" -dialect mysql

# Parse a SQL Server log
./bin/sqlparser -log examples/logs/sample_profiler.log -output table

# Monitor a log file in real time
./bin/sqlparser -monitor /var/log/postgresql/postgresql.log -dialect postgresql

Options:

-query FILE      Read SQL from file
-sql STRING      Read SQL from string
-log FILE        Parse SQL Server log file
-monitor FILE    Watch log file for new entries
-dialect NAME    mysql | postgresql | sqlserver | sqlite | oracle  (default: sqlserver)
-output FORMAT   json | table  (default: json)
-verbose         Verbose output
-config FILE     Config file path

What it supports

Statements: SELECT, INSERT, UPDATE, DELETE, EXPLAIN, all DDL (CREATE/DROP/ALTER TABLE, INDEX, VIEW, TRIGGER), transactions (BEGIN, COMMIT, ROLLBACK, SAVEPOINT), stored procedures and functions, MERGE, cursors, control flow (IF, WHILE, FOR, LOOP, REPEAT), exception handling (TRY/CATCH, RAISE, SIGNAL).

Advanced SQL: CTEs, window functions, set operations (UNION/INTERSECT/EXCEPT), scalar/correlated/derived subqueries, EXISTS/IN subqueries, PostgreSQL dollar-quoted strings.

Analysis: schema-aware validation (JSON/YAML schema files), execution plan parsing (EXPLAIN JSON/XML), bottleneck detection, dialect-specific optimization suggestions, real-time log monitoring with alert rules.

Performance

Benchmarked on Apple M2 Pro:

| Component | Cold | Cached | |-----------------|--------------|-----------| | Lexer | ~1826 ns/op | — | | Parser | ~1141 ns/op | — | | Analyzer | ~1786 ns/op | ~26 ns/op | | Schema validate | 155–264 ns | — | | Plan analysis | ~46 ns | — |

Development

make test        # run tests
make bench       # run benchmarks
make fmt         # format code
make all         # deps, fmt, lint, test, build

See EXAMPLES.md for usage examples and PERFORMANCE.md for benchmark details.

License

MIT — see LICENSE.