If in an SQL query you do SELECT 1 instead of specifying a column name, the result will be a selection with one column, in which all rows will have the value 1. This is often used to check for the existence of records or for test queries, when the data from the table is not important, only to get rows.

Example:

SELECT 1 FROM users WHERE age > 30;

This query will return as many rows with the number 1 as there are users over 30 years old, but the user data itself will not be returned.

Eelmine Edasi