Module params 

AST-level parameter binding for prepared statements.

Every Value::Placeholder("$N") in a parsed statement is rewritten to a concrete literal value via sqlparser’s VisitorMut. The visitor traverses every expression position the AST defines — CTE bodies, window specs, Update.from/returning/limit, Delete.returning, Insert.on_conflict, Expr::Array elements, Expr::AnyOp/AllOp right-hand sides, Expr::Interval, and any variant sqlparser adds in the future — without us maintaining a hand-written walker.

Why a visitor, not a hand-written walker

The previous implementation was a recursive match on ~20 Expr / Statement / Query variants. Every new sqlparser variant it didn’t enumerate was a silent bug: placeholders survived into the planner and surfaced as “unsupported expression: $1” in the resolver. The walker was opt-in where it had to be exhaustive to be correct. VisitorMut moves the exhaustiveness burden to sqlparser itself.

Enums

ParamValue

Parameter value for AST substitution.

Functions

bind_params

Substitute all $N placeholders in a parsed statement with concrete values.