Two: relational database

One: What is a relational database

A relational database is a database of multiple, interconnected, two-dimensional column tables.

Two: What is a relational model

Refers to a two-dimensional tabular model, so a relational database is a data organization composed of two-dimensional tables and their linkages

Three: What are the current popular relational databases?

Oracle DB2 SQL Server MYSQL

Four: Common operation of relational database

Data query, selection, projection, connection, and intersection in addition to data operations, delete modify query operations

Five: SQL (structured Query Language)

A structured query language between relational algebra and relational calculus, proposed in 1974, is a universal and powerful relational database language.

　　

Two: relational database