Enum ColumnType

#[non_exhaustive]
pub enum ColumnType<'frame> {
    Native(NativeType),
    Collection {
        frozen: bool,
        typ: CollectionType<'frame>,
    },
    Vector {
        typ: Box<ColumnType<'frame>>,
        dimensions: u16,
    },
    UserDefinedType {
        frozen: bool,
        definition: Arc<UserDefinedType<'frame>>,
    },
    Tuple(Vec<ColumnType<'frame>>),
}

A type of:

• a column in schema metadata
• a bind marker in a prepared statement
• a column a in query result set

Some of the variants contain a frozen flag. This flag is only used in schema metadata. For prepared statement bind markers and query result types those fields will always be set to false (even if the DB column corresponding to given marker / result type is frozen).

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Native(NativeType)

Types that are “simple” (non-recursive).

Collection

Collection types: Map, Set, and List. Those are composite types with dynamic size but constant predefined element types.

Fields

frozen: bool

If a collection is not frozen, elements in the collection can be updated individually. If it is frozen, the entire collection will be overwritten when it is updated. A collection cannot contain another collection unless the inner collection is frozen. The frozen type will be treated as a blob.

typ: CollectionType<'frame>

Type of the collection’s elements.

Vector

A composite list-like type that has a defined size and all its elements are of the same type. Intuitively, it can be viewed as a list with constant predefined size, or as a tuple which has all elements of the same type.

Fields

typ: Box<ColumnType<'frame>>

Type of the vector’s elements.

dimensions: u16

Length of the vector.

UserDefinedType

A C-struct-like type defined by the user.

Fields

frozen: bool

Analogous to ColumnType::Collection::frozen. If a UDT is not frozen, elements in the UDT can be updated individually. If it is frozen, the entire UDT will be overwritten when it is updated. A UDT cannot contain another UDT unless the inner UDT is frozen. The frozen type will be treated as a blob.

definition: Arc<UserDefinedType<'frame>>

Definition of the user-defined type.

Tuple(Vec<ColumnType<'frame>>)

A composite type with a defined size and elements of possibly different, but predefined, types.

Implementations

impl ColumnType<'_>

pub fn into_owned(self) -> ColumnType<'static>

Converts a ColumnType to an owned version, where all references are replaced with owned values.

Unfortunately, this allocates even if the type is already owned.

Trait Implementations

impl<'frame> Clone for ColumnType<'frame>

fn clone(&self) -> ColumnType<'frame>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'frame> Debug for ColumnType<'frame>

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<'frame> PartialEq for ColumnType<'frame>

fn eq(&self, other: &ColumnType<'frame>) -> bool

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'frame> Eq for ColumnType<'frame>

impl<'frame> StructuralPartialEq for ColumnType<'frame>