Databases

Terminology of relational model

A database is an organized collection of data. It is the collection of schemas, tables, queries, reports, views, and other objects. https://en.wikipedia.org/wiki/Database

• What is the primary key: title_id
• What is the foreign key: Pub_id
• What is the cardinality: 13

select count(title_id) as 'Cardinality of the «titles» table' from titles;

• What is its degree: 9
• What is the domain of contract: Smallint(6) NOT NULL

• What is the domain of country in the table Publishers: varchar(15) NOT NULL

What is SQL

SQL (Structured Query Language) is a special-purpose programming language designed for managing data held in a relational database management system (RDBMS), or for stream processing in a relational data stream management system (RDSMS). https://en.wikipedia.org/wiki/SQL

What is a Database management system - DBMS

https://en.wikipedia.org/wiki/Database

A database management system (DBMS) is a computer software application that interacts with the user, other applications, and the database itself to capture and analyze data. A general-purpose DBMS is designed to allow the definition, creation, querying, update, and administration of databases.

Well-known DBMSs include MySQL, PostgreSQL, MongoDB, Microsoft SQL Server, Oracle, Sybase, SAP HANA, and IBM DB2.

A database is not generally portable across different DBMSs, but different DBMS can interoperate by using standards such as SQL and ODBC or JDBC to allow a single application to work with more than one DBMS. Database management systems are often classified according to the database model that they support; the most popular database systems since the 1980s have all supported the relational model as represented by the SQL language.

The DBMS acronym is sometimes extended to indicate the underlying database model, with RDBMS for the relational, OODBMS for the object (oriented), and ORDBMS for the object-relational model. Other extensions can indicate some other characteristic, such as DDBMS for distributed database management systems.