Parameters and Rules

General Rules

Parameter binding and conditional expansion run before the command reaches MongoDB. They do not require SQL syntax. In JdbcTemplate, method annotations, or Mapper files, write a native command and bind its values; see Parameter Passing.

For example, this native command binds values instead of concatenating user input:

test.user_info.count({id: #{id}, name: #{name}})

The @{if, condition, command fragment} rule can select a command or fragment. Only the selected branch binds parameters; the resulting command must be valid MongoDB syntax.

SQL Fragment Rules

AND, OR, SET, and IN rules generate SQL fragments; they do not translate them into MongoDB commands. In particular, @{in} produces a parenthesized, comma-separated list of placeholders, not a native collection parameter.

Use native command syntax with bound values, and use general conditional rules to select fragments. This is a restriction on the generated syntax, not a lack of parameter binding or rule expansion.