1 the result is that true, is tested after using where true

1. all conditions are null
2. the first condition is null
3. all are not null

can get the right result, and where 1 can get the right result. After google, it is found that no one has done so. Why

SELECT * FROM `table` WHERE 1=1
SELECT * FROM `table` WHERE TRUE
SELECT * FROM `table` WHERE 1