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| | * What is the domain of ''country'' in the table ''Publishers'': '''varchar(15) NOT NULL''' | | * What is the domain of ''country'' in the table ''Publishers'': '''varchar(15) NOT NULL''' |
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| − | ==What is SQL==
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| − | 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
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| − | ==What is a Database management system - DBMS==
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| − | https://en.wikipedia.org/wiki/Database
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| − | 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.
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| − | Well-known DBMSs include MySQL, PostgreSQL, MongoDB, Microsoft SQL Server, Oracle, Sybase, SAP HANA, and IBM DB2.
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| − | 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.
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| − | 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.
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| − | <br />
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| | ==[[MySQL]]== | | ==[[MySQL]]== |
Revision as of 21:34, 19 June 2020
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
