-1' OR 3*2>999 --

Short answer: it looks like a classic SQL injection payload, not a normal boolean expression.

What it contains:

• -1' : attempts to break out of a string literal in SQL.
• OR 32>999 : a boolean expression where 32 = 6, so 6 > 999 is false.
• -- : SQL comment initiator, which ignores the rest of the line.

In a vulnerable query like: ... WHERE user = '$input' the payload could turn it into: ... WHERE user = '-1' OR 32>999 --' Since 32>999 is false, the right-hand side provides nothing new; the effect depends on the left-hand side and the surrounding query. The key point is that the injection tries to bypass checks by injecting a tautology or by closing a string, and the rest of the line is ignored due to the comment.

Important security note:

• Do not rely on input filtering. Use parameterized (prepared) queries, not string concatenation.
• Validate inputs, implement least-privilege database accounts, and consider using ORM/database APIs that separate code and data.

If you want, I can show a safe sanitized version of a typical query and how to test for injection safely.