Mojo::SQL safely generates and composes SQL statements. To prevent SQL injection
attacks, every ? in the input becomes a placeholder in the generated query, with
the corresponding value bound to it. Partial statements can be composed
recursively to build more complex queries.

Literal question marks can be escaped with ??.

Make partial statements optional to dynamically generate WHERE clauses.

If you need a little more control over the generated SQL query, you can also
bypass safety features with "sql_unsafe". But make sure to handle unsafe values
yourself with appropriate escaping functions for your database. For PostgreSQL
there are "escape_literal" and "escape_identifier" functions included with this
module.

For databases that do not support numbered placeholders like $1 and $2, you can
set a custom character with the placeholder option.