Terms of Art Glossary

This page contains a glossary of terms of art which appear, but are not defined, throughout this project's documentation. This page is not a tutorial, just a summary, and many related terms of art are not listed here. Countless web-hosted resources exist which cover, in detail, all of the terminology listed here. Interested readers are encouraged to feed these terms to their internet search engine of choice.

• DDL: Data Definition Language is the subset of SQL related to maintenance of database tables: CREATE, DROP, ALTER, etc.
• DML: Data Manipulation Language is the subset of SQL related to manipulating the contents of tables: INSERT, UPDATE, DELETE, etc.
• DQL: Data Query Language is the subset of SQL related to fetching results, i.e. SELECT. Whether INSERT...RETURNING also qualifies as DQL is a question left to those who define these terms formally.
• TCL: Transaction Control Language is the subset of SQL involving transactions: BEGIN, COMMIT, ROLLBACK, etc.
• Relational Theory is, in this context, the area of study from which SQL is derived. SQL does not, for reasons of practically, strictly conform to relational theory, but it's a close approximation.
• SQL: Structured Query Language is the primary interface between a database and its users. It encompasses DDL, DML, DQL, and TCL (see above).

This page was last updated on 2025年07月12日 15:11:36Z