SQL Glossary

Clear, example-backed definitions of the SQL and relational-database terms you meet most often — from primary keys and joins to ACID, isolation levels, and window functions. Every entry links to a hands-on tutorial where you can practise the concept in the free SQL editor.

Keys & Constraints

• Constraint
• Foreign Key
• Primary Key

Performance

• Clustered Index
• Index

Design

• Database Schema
• Denormalization
• Normalization

Querying

• Aggregate Function
• Common Table Expression (CTE)
• Inner Join
• NULL
• Outer Join
• SQL JOIN
• Subquery
• Window Function

Objects

• Materialized View
• Stored Procedure
• Trigger
• View

Procedural

• Cursor

Reliability

• ACID
• Deadlock
• Isolation Level
• Transaction

SQL Sublanguages

• DDL (Data Definition Language)
• DML (Data Manipulation Language)