get element from table which is not in another table sql code example

Example 1: join to find results not in another table

SELECT t1.name
FROM table1 t1
LEFT JOIN table2 t2 ON t2.name = t1.name
WHERE t2.name IS NULL

Example 2: sql select where id not exists in another table

where ID not in(select ID from T2 where HISTORY_FLG!=1)