Struct postgres_parser::sys::Const

#[repr(C)]pub struct Const {
    pub xpr: Expr,
    pub consttype: Oid,
    pub consttypmod: int32,
    pub constcollid: Oid,
    pub constlen: c_int,
    pub constvalue: Datum,
    pub constisnull: bool,
    pub constbyval: bool,
    pub location: c_int,
}

Const

Note: for varlena data types, we make a rule that a Const node's value must be in nonextended form (4byte header, no compression or external references). This ensures that the Const node is selfcontained and makes it more likely that equal() will see logically identical values as equal.

Fields

xpr: Expr

consttype: Oid

consttypmod: int32

pg_type OID of the constant's datatype

constcollid: Oid

typmod value, if any

constlen: c_int

OID of collation, or InvalidOid if none

constvalue: Datum

typlen of the constant's datatype

constisnull: bool

the constant's value

constbyval: bool

whether the constant is null (if true, constvalue is undefined)

location: c_int

whether this datatype is passed by value. If true, then all the information is stored in the Datum. If false, then the Datum contains a pointer to the information.

Trait Implementations

impl Debug for Const

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl Default for Const

fn default() -> Self

Returns the "default value" for a type.

impl Eq for Const

impl Hash for Const

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given [Hasher].

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given [Hasher].

impl PartialEq<Const> for Const

fn eq(&self, other: &Const) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Const) -> bool

This method tests for !=.

impl StructuralEq for Const

impl StructuralPartialEq for Const