JSON Logic to SQL Transpiler

A Go library that converts JSON Logic expressions into SQL. This library provides a clean, type-safe API for transforming JSON Logic rules into SQL WHERE clauses or standalone conditions, with support for multiple SQL dialects.

Features

• Complete JSON Logic Support: Implements all core JSON Logic operators
• SQL Dialect Support: Target BigQuery, Spanner, PostgreSQL, DuckDB, or ClickHouse
• Custom Operators: Extensible registry pattern for custom SQL functions
• Schema Validation: Optional field schema for strict column validation
• Structured Errors: Error codes and JSONPath locations for debugging
• Library & CLI: Both programmatic API and interactive REPL

Quick Start

go get github.com/h22rana/jsonlogic2sql@latest

package main

import (
    "fmt"
    "github.com/h22rana/jsonlogic2sql"
)

func main() {
    sql, err := jsonlogic2sql.Transpile(
        jsonlogic2sql.DialectBigQuery,
        `{">": [{"var": "amount"}, 1000]}`,
    )
    if err != nil {
        panic(err)
    }
    fmt.Println(sql) // Output: WHERE amount > 1000
}

Supported Operators

Category	Operators
Data Access	var, missing, missing_some
Comparison	==, ===, !=, !==, >, >=, <, <=
Logical	and, or, !, !!, if
Numeric	+, -, *, /, %, max, min
Array	in, map, filter, reduce, all, some, none, merge
String	in, cat, substr

Supported Dialects

Dialect	Constant
Google BigQuery	DialectBigQuery
Google Cloud Spanner	DialectSpanner
PostgreSQL	DialectPostgreSQL
DuckDB	DialectDuckDB
ClickHouse	DialectClickHouse

Documentation

• Getting Started - Installation and basic usage
• Operators - All supported operators with examples
• SQL Dialects - Dialect-specific SQL generation
• Custom Operators - Extend with your own operators
• Schema Validation - Field validation and type checking
• Examples - Comprehensive examples
• API Reference - Full API documentation
• Error Handling - Error codes and programmatic handling
• Development - Contributing and development guide
• REPL - Interactive testing tool

Important Notes

Semantic Correctness Assumption: This library assumes that the input JSONLogic is semantically correct. The transpiler generates SQL that directly corresponds to the JSONLogic structure without validating the logical correctness of the expressions.

SQL Injection: This library does NOT handle SQL injection prevention. The caller is responsible for validating input and using parameterized queries where appropriate.

Interactive REPL

make run

[BigQuery] jsonlogic> {">": [{"var": "amount"}, 1000]}
SQL: WHERE amount > 1000

[BigQuery] jsonlogic> :dialect
Select dialect: PostgreSQL

[PostgreSQL] jsonlogic> {"merge": [{"var": "a"}, {"var": "b"}]}
SQL: WHERE (a || b)

Development

make test      # Run all tests (3,000+ test cases)
make build     # Build REPL binary
make lint      # Run linter
make run       # Run REPL

License

This project is licensed under the MIT License - see the LICENSE file for details.