SQL SELECT Queries: Selecting Specific Columns

Select Specific Columns from a Table

Write an SQL query to select the columns 'product_name' and 'price' from the 'products' table.

Expected output: A result set showing only the product_name and price columns.

Hint: Use the SELECT keyword followed by the column names separated by commas.

Avoid Using SELECT *

Rewrite a query that uses SELECT * to select only the columns 'id', 'username', and 'email' from the 'users' table.

Expected output: A query that returns only id, username, and email columns.

Hint: Replace the asterisk with the specific column names.

You list the column names separated by commas after the SELECT keyword, for example: SELECT column1, column2 FROM table_name;

Selecting specific columns reduces data transfer, improves query performance, and avoids exposing unnecessary data.

The database will return an error indicating the column does not exist, or the query will fail to execute.