=== on 16 Jun 2016, 16:13:18 Ann Campbell wrote: https://www.researchgate.net/publication/222432151_Semantic_errors_in_SQL_queries_A_quite_complete_list === on 29 Aug 2018, 16:30:32 Alexandre Gigleux wrote: ---- CREATE TABLE TABLE1 ( value VARCHAR2(10) ) CREATE TABLE TABLE2 ( value VARCHAR2(10) ) INSERT INTO TABLE1 VALUES (1) INSERT INTO TABLE1 VALUES (2) INSERT INTO TABLE1 VALUES (NULL) INSERT INTO TABLE2 VALUES (2) INSERT INTO TABLE2 VALUES (NULL) SELECT * FROM TABLE1 SELECT * FROM TABLE2 -- KO SELECT * FROM TABLE1 WHERE VALUE NOT IN (SELECT VALUE FROM TABLE2) -- OK SELECT * FROM TABLE1 WHERE VALUE NOT IN (SELECT VALUE FROM TABLE2 WHERE VALUE IS NOT NULL) -- OK SELECT * FROM TABLE1 WHERE NOT EXISTS (SELECT 1 FROM TABLE2 WHERE TABLE1.VALUE = TABLE2.VALUE) ----