SQL Formatter

What is SQL Formatter?

SQL Formatter is an online tool that organizes complex SQL queries into a readable format. It transforms compressed one-line queries into well-structured code with proper indentation and line breaks, making the structure clear and easy to understand.

It supports 8 major SQL dialects including MySQL, PostgreSQL, Oracle, SQL Server, MariaDB, SQLite, Amazon Redshift, and Snowflake. You can customize keyword case conversion and indentation size. The syntax highlighting feature color-codes keywords, strings, numbers, and comments for enhanced readability.

Use Cases

• Analyzing Compressed Queries – When you need to understand long one-line SQL queries by breaking them down structurally
• Code Review – Before reviewing a colleague’s SQL, format it to improve readability
• Debugging – When troubleshooting complex JOINs or subqueries, clarify the structure to find errors
• Documentation – When attaching SQL to project documentation or wikis in a clean, organized format
• Learning – Visually understand and learn SQL syntax structure
• Coding Style Consistency – Align SQL writing style consistently across your team
• Log Analysis – Convert queries extracted from application logs into readable format

Key Features

• 8 SQL Dialect Support – Supports Standard SQL, MySQL, PostgreSQL, Oracle PL/SQL, SQL Server T-SQL, MariaDB, SQLite, Amazon Redshift, and Snowflake. Formatting adapts to each dialect’s special syntax.
• Keyword Case Conversion – Choose between UPPER (uppercase), lower (lowercase), or preserve (keep original) for keyword styling.
• Adjustable Indentation – Select 2-space or 4-space indentation to match your personal or team style.
• Syntax Highlighting – Color-codes keywords (blue), strings (red), numbers (purple), comments (gray), and operators for improved code readability.
• Line Numbers – Displays line numbers on both input and output panels for easy line reference.
• File Upload/Download – Upload .sql files directly and download formatted results as .sql files.
• Sample SQL – Test functionality quickly with 5 sample queries: SELECT, INSERT, JOIN, Subquery, and CREATE TABLE.
• Auto-save – Your SQL is automatically saved in the browser and recovered even after page refresh.
• Clipboard Copy – Copy formatted results to clipboard with a single click.
• Real-time Conversion – Formatting applies instantly as you type, showing results immediately.

How to Use

1. Enter SQL – Type or paste your SQL query into the left input area. You can also load examples using the ‘Samples’ button.
2. Set Options – At the top, select your SQL dialect, keyword case, and indentation size.
3. View Results – Check the formatted SQL in the right output area. Conversion happens automatically as you type.
4. Copy or Download – Use the ‘Copy’ button to copy to clipboard, or ‘Download’ button to save as a .sql file.

Supported SQL Dialects Details

SQL Formatter supports SQL syntax for the following database systems:

• Standard SQL – ANSI/ISO SQL standard syntax. Compatible with most RDBMS systems.
• MySQL – Supports MySQL and MySQL-compatible databases (Percona, TiDB, etc.). Recognizes MySQL-specific syntax like LIMIT and AUTO_INCREMENT.
• PostgreSQL – Supports PostgreSQL extended syntax including RETURNING, UPSERT, arrays, and JSON operators.
• Oracle PL/SQL – Supports Oracle Database’s PL/SQL procedural language. Recognizes Oracle functions like DECODE, NVL, and ROWNUM.
• SQL Server T-SQL – Supports Microsoft SQL Server’s Transact-SQL. Recognizes TOP, NOLOCK, variables (@), etc.
• MariaDB – Supports MariaDB’s MySQL extensions. Recognizes SEQUENCE, window function extensions, etc.
• SQLite – Supports SQLite’s lightweight syntax. Recognizes AUTOINCREMENT, VACUUM, ATTACH, etc.
• Amazon Redshift – Supports AWS Redshift’s analytical query syntax. Recognizes DISTKEY, SORTKEY, COPY, UNLOAD, etc.
• Snowflake – Supports Snowflake cloud data platform syntax. Recognizes VARIANT, FLATTEN, QUALIFY, etc.

Formatting Rules

SQL Formatter applies the following rules to organize queries:

• Clause Line Breaks – Major clauses like SELECT, FROM, WHERE, JOIN, ORDER BY start on new lines.
• Column Alignment – Column lists in SELECT clauses are placed on separate lines with proper indentation.
• Condition Alignment – AND/OR conditions in WHERE clauses are placed on separate lines for clear distinction.
• Subquery Indentation – Subqueries are indented one level deeper than parent queries to show hierarchy.
• Parenthesis Alignment – Opening and closing parentheses are consistently positioned.
• Query Separation – Multiple SQL statements are separated by blank lines.

Usage Tips

• Large Queries – Can process thousands of lines of SQL, but very large files may impact browser performance.
• Comment Preservation – Both single-line (–) and multi-line (/* */) comments are preserved.
• String Preservation – String content enclosed in single or double quotes remains unchanged.
• Tab Key – Pressing Tab in the input area inserts spaces based on the configured indentation size.
• Use Auto-save – If you accidentally close the page during work, auto-saved content will be recovered.

Details

Results in SQL Formatter are generated from your input values and selected options.

For final decisions, cross-check with official guidelines or expert review.

Frequently Asked Questions