MySQL to JSON Lines Converter

About MySQL to JSON Lines Converter

Convert MySQL database dumps (CREATE TABLE and INSERT statements) to JSON Lines (JSONL) format, also known as newline-delimited JSON. Each row becomes a separate JSON object or array on its own line, perfect for streaming and big data applications.

Key Features

• Line-Delimited Format: One JSON object/array per line
• Object Mode: Convert rows to objects using column names as keys
• Array Mode: Convert rows to simple arrays
• Streaming Ready: Process large datasets line-by-line
• Big Data Compatible: Works with Hadoop, Spark, and other tools
• File Download: Save as .jsonl file
• Instant Preview: Real-time conversion as you type

How to Use

1. Input MySQL Data: Paste your MySQL dump or upload a .sql file
2. Configure Options: Choose whether to use columns for object keys
3. Review Output: The JSON Lines updates automatically
4. Copy or Download: Use the JSONL in your application

What is JSON Lines?

JSON Lines is a text format where:

• Each line is a valid JSON value (object or array)
• Lines are separated by newline characters (\n)
• Files can be processed line-by-line without loading entire dataset
• Ideal for streaming, logging, and big data processing

Example Conversion

MySQL Input:

CREATE TABLE employees (
  id INT PRIMARY KEY,
  name VARCHAR(100),
  age INT,
  department VARCHAR(50)
);

INSERT INTO employees VALUES (1, 'John Doe', 28, 'Engineering');
INSERT INTO employees VALUES (2, 'Jane Smith', 34, 'Marketing');

JSON Lines Output (Object Mode):

{"id":"1","name":"John Doe","age":"28","department":"Engineering"}
{"id":"2","name":"Jane Smith","age":"34","department":"Marketing"}

JSON Lines Output (Array Mode):

["id","name","age","department"]
["1","John Doe","28","Engineering"]
["2","Jane Smith","34","Marketing"]

Common Use Cases

• Data Streaming: Process large MySQL exports without loading into memory
• Log Files: Structured logging of database changes in JSON Lines format
• Big Data: Import MySQL data into Hadoop, Spark, or other big data tools
• ETL Pipelines: Extract MySQL data and load efficiently into data warehouses
• Database Import: Bulk import MySQL data into MongoDB, Elasticsearch, etc.
• API Responses: Stream large MySQL result sets from APIs
• Data Migration: Migrate MySQL databases to NoSQL systems

Advantages of JSON Lines

• Streamable: Process one line at a time
• Appendable: Add new records without parsing entire file
• Simple: Easy to generate and parse
• Robust: Corrupted line doesn't affect others
• Universal: Supported by many data processing tools
• Memory Efficient: No need to load entire dataset

Processing JSON Lines

Python:

import json

with open('output.jsonl', 'r') as f:
    for line in f:
        data = json.loads(line)
        print(data['name'], data['age'])

JavaScript/Node.js:

const fs = require('fs');
const readline = require('readline');

const rl = readline.createInterface({
    input: fs.createReadStream('output.jsonl')
});

rl.on('line', (line) => {
    const data = JSON.parse(line);
    console.log(data.name, data.age);
});

Command Line (jq):

cat output.jsonl | jq '.name'

Tools Supporting JSON Lines

• Apache Spark
• Hadoop
• MongoDB (mongoimport)
• Elasticsearch (bulk API)
• BigQuery
• jq (command-line JSON processor)
• Pandas (Python data analysis)
• Apache Kafka

Supported MySQL Syntax

• CREATE TABLE: Extracts column names from table definitions
• INSERT INTO: Parses VALUES clauses with quoted strings
• Column Lists: Supports INSERT INTO table (col1, col2) VALUES format
• Quoted Values: Handles single and double quotes properly
• Escaped Quotes: Processes escaped quotes in string values

Tips for Best Results

• Include CREATE TABLE for automatic column name detection
• Use object mode for self-describing data
• Use array mode for minimal file size
• Process line-by-line for large MySQL exports
• Validate with JSON Lines validators if needed
• Use .jsonl or .ndjson file extension

Privacy & Security

All conversions happen locally in your browser. Your MySQL data is never uploaded to any server, ensuring complete privacy and security.