I realized a difference in filtering by where clause in conjunction with the `in` operator and `notNull` when I wanted to suppress the Null filled field and it did not happen, looking like the `and` was ignored; but the order does NOT make any difference. ~~~ SQLite version 3.36.0 2021-06-18 18:36:39 Enter ".help" for usage hints. sqlite> .mode box sqlite> select TagGroup,TagName,Op,typeof(TagName) from ExitTagList where Op in ('write','written') and Op notNull; ┌──────────┬─────────────┬─────────┬─────────────────┐ │ TagGroup │ TagName │ Op │ typeof(TagName) │ ├──────────┼─────────────┼─────────┼─────────────────┤ │ │ │ written │ null │ │ ExitHsk │ REQUEST │ write │ text │ │ ExitHsk │ SuccessCode │ write │ text │ │ ExitHsk │ VALID │ write │ text │ └──────────┴─────────────┴─────────┴─────────────────┘ sqlite> select TagGroup,TagName,Op,typeof(TagName) from ExitTagList where Op notNull and Op in ('write','written'); ┌──────────┬─────────────┬─────────┬─────────────────┐ │ TagGroup │ TagName │ Op │ typeof(TagName) │ ├──────────┼─────────────┼─────────┼─────────────────┤ │ │ │ written │ null │ │ ExitHsk │ REQUEST │ write │ text │ │ ExitHsk │ SuccessCode │ write │ text │ │ ExitHsk │ VALID │ write │ text │ └──────────┴─────────────┴─────────┴─────────────────┘ sqlite> select TagGroup,TagName,Op,typeof(TagName) from ExitTagList where Op in ('write','written') and Op notNull and TagGroup = 'ExitHsk'; ┌──────────┬─────────────┬───────┬─────────────────┐ │ TagGroup │ TagName │ Op │ typeof(TagName) │ ├──────────┼─────────────┼───────┼─────────────────┤ │ ExitHsk │ REQUEST │ write │ text │ │ ExitHsk │ SuccessCode │ write │ text │ │ ExitHsk │ VALID │ write │ text │ └──────────┴─────────────┴───────┴─────────────────┘ sqlite> select * from ExitTagList; ┌──────────┬─────────────┬─────────┬───────┐ │ TagGroup │ TagName │ Op │ Used │ ├──────────┼─────────────┼─────────┼───────┤ │ │ │ written │ 19310 │ │ │ │ loaded │ 27420 │ │ ExitHsk │ REQUEST │ write │ 13115 │ │ ExitHsk │ REQUEST │ read │ 13115 │ │ ExitHsk │ SuccessCode │ write │ 9218 │ │ ExitHsk │ SuccessCode │ read │ 9218 │ │ ExitHsk │ VALID │ write │ 4609 │ │ ExitHsk │ VALID │ read │ 4609 │ └──────────┴─────────────┴─────────┴───────┘ sqlite> ~~~ What did I miss? Or is this a buggy behaviour?