Function regexp_replace 

pub fn regexp_replace<'a, V, E, P, R>(
    expr: E,
    pattern: P,
    replacement: R,
) -> SQLExpr<'a, V, <V::DialectMarker as DialectTypes>::Text, E::Nullable, <<E::Aggregate as AggregateKind>::Or<P::Aggregate> as AggregateKind>::Or<R::Aggregate>, (E::Sources, (P::Sources, R::Sources))>
where
    V: SQLParam + 'a,
    V::DialectMarker: DialectSupports<PostgresString>,
    E: Expr<'a, V>,
    E::SQLType: Textual,
    P: Expr<'a, V>,
    P::SQLType: Textual,
    P::Aggregate: AggregateKind,
    R: Expr<'a, V>,
    R::SQLType: Textual,
    R::Aggregate: AggregateKind,

Replaces the first POSIX regular expression match (REGEXP_REPLACE), on PostgreSQL.

All arguments must be text. The result is text and keeps expr’s nullability. To replace every match, use regexp_replace_flags with "g".

Examples

let cleaned = regexp_replace(users.name, "[^a-z]", "");
assert_eq!(cleaned.sql(), r#"REGEXP_REPLACE ("users"."name", $1, $2)"#);