Question

Retrieving only certain rows from a table is known as projection. ​

Answer 1

Projection in the context of databases involves selecting specific columns of data from a table.

Step-by-step explanation:

Projection in the context of databases is a term used to describe the retrieval of only certain rows or columns from a table. It involves selecting specific columns of data from a table, rather than retrieving the entire table. This is commonly done using the SQL SELECT statement, where you specify the name of the columns you want to retrieve.

For example, if you have a table with columns 'name', 'age', and 'gender', and you only want to retrieve the names and ages of the people, you can use a SELECT statement like this:

SELECT name, age FROM table_name;

This will return a result set with only the 'name' and 'age' columns.