Struct Prepared 

pub struct Prepared<D, Params, Output> { /* private fields */ }

A query rendered once, with its Value::Placeholder(name) slots left unresolved, reusable across many .load(executor, params) calls. load takes the exact Params struct prepare!{} generated for this query, so a missing or mistyped value is caught. The dialect it was rendered in stays in its type, so it can only be run by an executor of that dialect, the same rule Select and DynSelect follow.

Params is a free parameter, though: nothing ties the placeholder names baked into the template to the struct that fills them. A query built from one prepare! struct and run with another is therefore caught at resolve rather than at compile time. Placeholder names are qualified by the module and struct they were declared in, so that mismatch is always an UnresolvedPlaceholder and never a value bound to the wrong slot.

Implementations

impl<D, Params: PreparedParams, Output> Prepared<D, Params, Output>

pub fn resolve( &self, params: Params, ) -> Result<(String, Vec<Value>), UnresolvedPlaceholder>

Substitutes every named placeholder with the matching value from params, producing the same (String, Vec<Value>) shape to_sql() returns.