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Formateur SQL

SQL (Structured Query Language) est le langage standard pour les bases de données relationnelles. Cet outil formate les requêtes SQL avec une indentation correcte, met les mots-clés en majuscules et structure les requêtes complexes pour la lisibilité. Prend en charge les dialectes SQL courants.

Specifications

Cas d'utilisation courants

  • Formater du SQL minifié provenant de logs ou de la sortie ORM
  • Rendre les requêtes complexes lisibles pour la revue de code
  • Préparer du SQL pour la documentation
  • Déboguer et comprendre les requêtes existantes

Fonctionnalites

  • Mise en forme SQL avec indentation cohérente
  • Mots-clés SQL en majuscules (SELECT, FROM, WHERE, etc.)
  • Formater les JOIN complexes et sous-requêtes
  • Gérer les CTE (Common Table Expressions) avec WITH
  • Prise en charge des fonctions de fenêtrage
  • Prise en charge de 6 dialectes SQL (Standard, PostgreSQL, MySQL, MariaDB, SQLite, T-SQL)
  • Extraction des noms de tables
  • Bascule de vue minifiée
  • Affichage de l'économie de taille (original vs minifié)

Exemples

Requête complexe avec JOIN

Essayer →

Une requête avec agrégation, jointure et tri.

SELECT
  u.id,
  u.name,
  COUNT(o.id) AS order_count
FROM users u
LEFT JOIN orders o ON u.id = o.user_id
WHERE u.active = true
GROUP BY u.id, u.name
HAVING COUNT(o.id) > 5
ORDER BY order_count DESC

Conseils

  • Formatez les requêtes avant de les commiter dans le contrôle de version.
  • Les mots-clés en majuscules améliorent la lisibilité mais ne sont pas requis par SQL.
  • Les sous-requêtes doivent être indentées pour plus de clarté.

Comprendre Formateur SQL

SQL (Structured Query Language) has been the standard language for relational databases since the 1970s. It provides a declarative syntax for querying, manipulating, and managing data across database systems including PostgreSQL, MySQL, SQLite, SQL Server, and Oracle. While each database adds proprietary extensions, the core language is remarkably consistent.

SQL statements fall into several categories. Data Manipulation Language (DML) includes SELECT, INSERT, UPDATE, and DELETE for reading and modifying data. Data Definition Language (DDL) includes CREATE, ALTER, and DROP for managing database objects. Data Control Language (DCL) handles permissions with GRANT and REVOKE. Modern SQL also supports Common Table Expressions (CTEs) with WITH clauses, window functions for analytics, and JSON operations for semi-structured data.

Formatting SQL is essential for readability and maintenance. A complex query with joins, subqueries, and aggregations can become incomprehensible when compressed to a single line — common in ORM-generated queries, application logs, and database monitoring tools. Consistent formatting with uppercased keywords, proper indentation, and aligned clauses makes queries easier to review, debug, and optimize.

SQL formatting also aids performance analysis. Well-formatted queries make it easier to identify missing indexes (by seeing which columns appear in WHERE and JOIN conditions), spot unnecessary subqueries that could be rewritten as joins, and understand the logical flow of complex queries involving CTEs and window functions.

SQL is case-insensitive for keywords, so SELECT and select are treated identically by the database engine. Uppercase keywords (SELECT, FROM, WHERE, JOIN) are a widely followed convention that improves readability by visually distinguishing SQL keywords from table and column names. Most formatters and style guides recommend uppercase keywords for this reason.

A Common Table Expression (CTE) is a named temporary result set defined with the WITH keyword that exists for the duration of a single query. CTEs improve readability by breaking complex queries into named steps, replacing deeply nested subqueries with a sequential, top-to-bottom structure. Recursive CTEs extend this capability to traverse hierarchical data like organizational charts or threaded comments.

Core SQL syntax (SELECT, JOIN, WHERE, GROUP BY) is consistent across database dialects, but differences appear in proprietary features. MySQL uses backticks for quoting identifiers, PostgreSQL uses double quotes, and SQL Server uses square brackets. Functions, data types, and advanced features like LATERAL joins, MERGE, and UPSERT also vary by dialect. This formatter handles standard SQL syntax that works across all major databases.

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