pub trait NullProbeRow<Row: ?Sized>: FromDrizzleRow<Row> {
// Required method
fn is_null_at(row: &Row, offset: usize) -> Result<bool, DrizzleError>;
}Expand description
A multi-column row type that can check whether it is absent (NULL).
This makes Option<T> work as a FromDrizzleRow target for a model,
as in a LEFT JOIN where the joined table may have no matching row.
The table macros implement this for each select model. Single-column
types (i32, String, …) have their own Option<T> impls instead.
Required Methods§
Sourcefn is_null_at(row: &Row, offset: usize) -> Result<bool, DrizzleError>
fn is_null_at(row: &Row, offset: usize) -> Result<bool, DrizzleError>
Returns true if the column at offset is NULL.
§Errors
Returns an error if the row cannot be inspected at offset (e.g. the
driver reports an out-of-range index or conversion failure).
Dyn Compatibility§
This trait is not dyn compatible.
In older versions of Rust, dyn compatibility was called "object safety".