Cours et exercices corrigés en SQL

Constraints allow you to limit the type of data to insert into a table. These constraints can be specified when creating the table using the CREATE TABLE statement, or after creating... Lire la suite

Data types represent a kind of data that can be stored in the database. The data type is the set of representable values. It is also known as an attribute that specifies a data type... Lire la suite

An operator is a reserved word or character used primarily in the WHERE clause of an SQL statement to perform operations, such as comparisons and arithmetic operations. These operators... Lire la suite

A table is a set of data relating to the same entity. It is structured in the form of a table. A table can also be called a relation (it contains the data which are in relation to... Lire la suite

A coherent computer system of information likely to be used simultaneously by several people. In fact, a database is a collection of files shared by several users. It is therefore... Lire la suite

SQL is a language for operating databases; it includes creating, deleting, extracting lines, modifying lines, etc. databases. SQL is an American National Standards Institute (ANSI)... Lire la suite