A join is used to combine data from two or more tables based on a common column or set of columns. There are several types of joins in SQL, including inner join, left join, right join, and ...Read more

A stored procedure is a set of SQL statements that are stored in the database and can be executed by calling the procedure. It is used to perform a specific task or set of tasks. When ...Read more

A subquery is a query that is nested inside another query. It is used to retrieve data that will be used in the main query. When students first learn SQL, they often write simple queries that ...Read more

A view is a virtual table that is created based on the result of a query. It allows users to see a subset of the data in a table without actually modifying the data. Before understanding ...Read more

A foreign key is a column or set of columns in a table that refers to the primary key of another table. It is used to establish a relationship between two tables.When we study databases, one important idea is ...Read more