Function floor 

pub fn floor<'a, V, E>(expr: E) -> SQLExpr<'a, V, Double, E::Nullable, Scalar>
where
    V: SQLParam + 'a,
    E: Expr<'a, V>,
    E::SQLType: Numeric,

FLOOR - rounds a number down to the nearest integer.

Returns Double type, preserves nullability.

Example

use drizzle_core::expr::floor;

// SELECT FLOOR(users.price)
let floored = floor(users.price);