-1" OR 5*5=26 --

This looks like an SQL injection payload. It’s meant to alter the logic of a query by closing a string literal, injecting an OR condition, and then commenting out the rest of the query.

Key points:

• 55 = 26 is false (since 55 = 25).
• The part -- is a SQL comment marker, so anything after it is ignored by the database.
• The -1" part is an attempt to terminate a quoted string in the query.

Net effect in a real query depends on how the DB engine evaluates booleans and how the input is embedded. In many cases, if a non-empty string or a non-zero number is treated as true, the injection could bypass parts of the intended check; but the exact result is dialect-specific.

Important safety note:

• Do not concatenate user input into SQL queries. Use parameterized queries (prepared statements), proper input validation, and least-privilege database accounts to prevent SQL injection.

If you’re studying this for an exam, the expected takeaway is:

• Recognize it as an injection attempt.
• Know that 5*5=26 is false (so the OR part would rely on the left-hand side).
• Understand that -- starts a comment, which is how many injections try to ignore the rest of the query.
• Be able to explain defensive measures.