Complex boolean logic: when combining three or more AND/OR conditions in SQL, is it usually easier to switch to NOT and NOT IN instead of using parentheses and explicit logic?

Introduction / Context:
SQL predicates often involve multiple conditions. The question asserts that with three or more AND/OR terms, it is typically easier to use NOT and NOT IN. This probes best practices for clarity and correctness in boolean logic.

Given Data / Assumptions:

• We may have complex filters across multiple columns.
• We can employ parentheses, operator precedence, and De Morgan’s laws.
• Readability and correctness are primary goals.

Concept / Approach:
While NOT and NOT IN are valid, they are not inherently simpler. Good practice is to write clear, positive logic with explicit parentheses to control evaluation and avoid precedence surprises. Use IN/NOT IN for set membership when it simplifies expression, but do not default to negation for complexity. For example, WHERE (status IN ('NEW','PENDING')) AND (amount >= 100) OR (vip_flag = true) may be clearer than a negated equivalent. Parentheses communicate intent and prevent logic bugs.

Step-by-Step Solution:

Verification / Alternative check:
Create a small truth table to compare the original AND/OR logic with a proposed NOT/NOT IN rewrite; ensure equivalence and prefer the clearer version.

Why Other Options Are Wrong:

• “Correct” overgeneralizes—negation can obscure intent.
• Limiting by data type or client UI is irrelevant; this is about logical clarity.
• Creating views is unnecessary for writing clear predicates.

Common Pitfalls:
Relying on default precedence (AND before OR) without parentheses, and misusing NOT IN with NULLs (which can yield unexpected filtering due to three-valued logic). Prefer explicit parentheses and consider IS DISTINCT FROM where supported.

Final Answer:
Incorrect