SQL Formatter

A SQL formatter tool written in Go that can be used both as a library and as a CLI command-line tool.

中文说明

Features

• 🔧 Format compressed SQL statements into readable multi-line format
• 📚 Can be integrated into your projects as a Go library
• 💻 Provides command-line tool with multiple input methods
• ⚙️ Configurable formatting options (indent size, keyword case, etc.)
• 🚀 Supports complex SQL statements including JOIN, subqueries, etc.

Supported SQL Statements

• SELECT (including JOIN, WHERE, GROUP BY, HAVING, ORDER BY, LIMIT, etc.)
• INSERT
• UPDATE
• DELETE

Installation

As a Library

go get github.com/BruceDu521/sql-formatter

Compile CLI Tool

go build -o sqlformatter cmd/main.go

Or download pre-built binaries from Releases.

Usage

As a Library

package main

import (
    "fmt"
    "log"
    
    sqlformatter "github.com/BruceDu521/sql-formatter"
)

func main() {
    // Create formatter
    formatter := sqlformatter.NewFormatter()
    
    // Configuration options
    formatter.IndentSize = 2      // Number of spaces for indentation
    formatter.KeywordUpper = true // Use uppercase for keywords
    
    // Format SQL
    sql := "select u.id, u.name from users u where u.age > 25"
    formatted, err := formatter.Format(sql)
    if err != nil {
        log.Fatal(err)
    }
    
    fmt.Println(formatted)
}

CLI Command Line Tool

Basic Usage

# Direct SQL input
./sqlformatter -sql "select * from users where id = 1"

# Read from file
./sqlformatter -input input.sql

# Output to file
./sqlformatter -input input.sql -output formatted.sql

# Use pipe
echo "select * from users" | ./sqlformatter

Command Line Options

Options:
  -sql string      SQL statement to format
  -input string    Input SQL file
  -output string   Output file
  -indent int      Number of spaces for indentation (default: 2)
  -uppercase       Use uppercase for keywords (default: true)
  -help            Show help information

Examples

SELECT Statement

Input:

select u.id, p.product_name, u.name from users u join products p on u.id = p.user_id where u.age > 25 and p.category = 'electronics' group by u.id order by p.price desc limit 10

Output:

SELECT
  u.id,
  p.product_name,
  u.name
FROM
  users u
  JOIN products p on u.id = p.user_id
WHERE
  u.age > 25 and p.category = 'electronics'
GROUP BY
  u.id
ORDER BY
  p.price desc
LIMIT
  10

INSERT Statement

Input:

INSERT INTO users (name, email) VALUES ('Alice', '[email protected]')

Output:

INSERT INTO users
  (name, email)
VALUES
  ('Alice', '[email protected]')

UPDATE Statement

Input:

UPDATE users SET name = 'John', email = '[email protected]' WHERE id = 1

Output:

UPDATE users
SET
  name = 'John',
  email = '[email protected]'
WHERE
  id = 1

DELETE Statement

Input:

DELETE FROM users WHERE age < 18

Output:

DELETE FROM users
WHERE
  age < 18

Project Structure

sql-formatter/
├── formatter.go        # Core formatting logic
├── cmd/
│   └── main.go        # CLI tool
├── example/
│   └── main.go        # Usage examples
├── formatter_test.go  # Unit tests
├── go.mod             # Go module file
├── README.md          # Project documentation (English)
├── README_zh.md       # Project documentation (Chinese)
├── test.sql           # Test SQL file
└── formatted.sql      # Formatted output example

Running Examples

# Run library usage example
go run example/main.go

# Run CLI tool
go run cmd/main.go -help
go run cmd/main.go -sql "select * from users"
go run cmd/main.go -input test.sql

# Run tests
go test -v

# Run benchmarks
go test -bench=.

Development Roadmap

• Support more SQL statement types (CREATE TABLE, ALTER TABLE, etc.)
• Add more formatting options
• Support different database dialects

Contributing

Issues and Pull Requests are welcome!

License

MIT License