Why use WHERE 1 or WHERE 1=1?
Basically it is just for programmer convenience since you can just add additional conditions with AND... after that and it has no impact on execution time.

Check out these links to Stackoverflow:


Why would someone use WHERE 1=1 AND  in a SQL
clause?
“where 1=1”
statement


Note that WHERE 1 is identical to WHERE 1=1; both mean WHERE TRUE but the former is rejected by many database management systems as not really being boolean.