A database is software that manages access to data so that it can be shared by multiple users. Databases have various data models, such as hierarchical, network, and object-oriented types, but relational databases are the most widely used type. Relational databases manage data in two-dimensional tables in rows and columns and manage the relationships between tables.
Workbench provides functions for operating these relational databases.
Terminology related to relational databases is explained below.
SQL is a language that can operate relational databases. SQL includes Data Definition Language (DDL) for creating, changing, and deleting tables, Data Manipulate Language (DML) for updating, deleting and searching data, and Data Control Language (DCL) for operating, determining, and cancelling data.
SQL is a standards specification but conformance varies according to the vendor.
A schema expresses the element structure of tables and views.
A virtual table formed by extracting columns from one or more tables.
Intended to improve the efficiency of data searches in databases.
A constraint can define the conditions for data that can be entered in a table. Constraints include primary keys and external keys.
