Function left 

pub fn left<'a, V, E, N>(
    expr: E,
    n: N,
) -> SQLExpr<'a, V, <V::DialectMarker as DialectTypes>::Text, <E::Nullable as NullOr<N::Nullable>>::Output, <E::Aggregate as AggOr<N::Aggregate>>::Output>
where
    V: SQLParam + 'a,
    V::DialectMarker: LeftRightSupport,
    E: Expr<'a, V>,
    E::SQLType: Textual,
    N: Expr<'a, V>,
    N::SQLType: Integral,
    N::Nullable: Nullability,
    E::Nullable: NullOr<N::Nullable>,
    N::Aggregate: AggregateKind,
    E::Aggregate: AggOr<N::Aggregate>,

LEFT - returns the first n characters of a string (PostgreSQL and MySQL).

The result is nullable when either argument is nullable.

Example

use drizzle_core::expr::left;

// SELECT LEFT(users.name, 3)
let prefix = left(users.name, 3);