🎁 New User? Get 20% off your first purchase with code NEWUSER20 Register Now →
Menu

Categories

Databases Beginner

What is SQL?

Structured Query Language — the standard language for managing and querying data in relational databases.

SQL is used to create, read, update, and delete data in relational databases. Key statements include SELECT (query), INSERT (add), UPDATE (modify), DELETE (remove), CREATE TABLE, and ALTER TABLE.

SQL supports complex operations like JOINs (combining tables), GROUP BY (aggregation), subqueries, transactions, and views. Major SQL databases include PostgreSQL, MySQL, SQL Server, and Oracle.

Related Terms

Cursor
A database object that enables row-by-row processing of query results, useful for operations that cannot be done in bulk.
Prepared Statement
A pre-compiled SQL template that uses parameters instead of literal values, preventing SQL injection and improving performance.
Write-Ahead Log (WAL)
A technique where changes are first written to a log before being applied to the database, ensuring crash recovery and data integrity.
Graph Database
A database that uses graph structures with nodes, edges, and properties to store and query highly connected data.
Normalization
The process of organizing database tables to reduce data redundancy and improve data integrity.
Query Optimization
The process of improving database query performance through indexing, query rewriting, and schema design techniques.
 View All Databases Terms →