Description\n-----------\n\nIn MariaDB, FALSE is a synonym of 0 and TRUE is a synonym of 1. These constants are case insensitive, so TRUE, True, and true are equivalent.\n\nThese terms are not synonyms of 0 and 1 when used with the IS operator. So, for example, 10 IS TRUE returns 1, while 10 = TRUE returns 0 (because 1 != 10).\n\nThe IS operator accepts a third constant exists: UNKNOWN. It is always a synonym of NULL.\n\nTRUE and FALSE are reserved words, while UNKNOWN is not.\n\nURL: https://mariadb.com/docs/server/reference/sql-structure/sql-language-structure/sql-language-structure-boolean-literals