What common mistake do developers make with Aggregates, why does the mistake cause problems, and what is the safer approach?

What common mistake do developers make with Aggregates, why does the mistake cause problems, and what is the safer approach? One recurring problem with aggregates is applying it without understanding the boundary it protects. Concatenating request parameters into raw SQL expressions instead of passing values through the query builder bindings. In addition, Count, sum, average, minimum and maximum operations compute summary values in the database. Safer engineering approach: keep the responsibility in the correct layer, use the framework's supported API, validate and authorize inputs, avoid hidden side effects, and verify the behavior with tests.