SQL Dummy File

SQL (Structured Query Language) was developed at IBM in the 1970s based on Edgar Codd's relational model. It was standardized by ANSI in 1986 and has been the dominant language for relational database management ever since. SQL is used to create, read, update, and delete data in relational databases, as well as to define database schemas, manage permissions, and control transactions. SQL files contain SQL statements that can be executed against a database engine.

SQL files serve many purposes: database migrations (schema changes), data seeding (populating test data), database backups (as SQL dump files), and documentation of database structure. Tools like pg_dump, mysqldump, and sqlite3's .dump command export entire databases as SQL files containing CREATE TABLE and INSERT statements. These dump files can be used to recreate the database on another system, making SQL files essential for database portability and backup.

While the ANSI SQL standard provides a common foundation, every major database system (PostgreSQL, MySQL, SQLite, SQL Server, Oracle) has its own dialect with proprietary extensions. PostgreSQL SQL differs from MySQL SQL, which differs from T-SQL (SQL Server). SQL files are therefore often database-specific. Modern tools like Flyway, Liquibase, and Alembic use SQL files for database version control, tracking which migrations have been applied to keep schema in sync across development, staging, and production environments.