[−][src]Function pgx::htup::heap_getattr
pub fn heap_getattr<T: FromDatum>(
tuple: &PgBox<HeapTupleData>,
attno: usize,
tupdesc: &PgTupleDesc<'_>
) -> Option<T>
Extract an attribute of a heap tuple and return it as a Datum.
This works for either system or user attributes. The given attnum
is properly range-checked.
If the field in question has a NULL value, we return None
.
Otherwise, a Some(T)
'tup' is the pointer to the heap tuple. 'attnum' is the attribute number of the column (field) caller wants. 'tupleDesc' is a pointer to the structure describing the row and all its fields.
attno
is 1-based