Enum AlterAction 

pub enum AlterAction {
    AddColumn {
        name: String,
        type_name: String,
        required: bool,
    },
    DropColumn {
        name: String,
        if_exists: bool,
    },
    AddIndex {
        target: IndexTarget,
        if_not_exists: bool,
    },
    AddUnique {
        target: IndexTarget,
        if_not_exists: bool,
    },
    DropIndex {
        target: IndexTarget,
        if_exists: bool,
    },
    AddLink {
        name: String,
        target: String,
        local_key: String,
        target_key: String,
    },
}

An individual ALTER TABLE action.

Variants

AddColumn

Fields

name: String

type_name: String

required: bool

DropColumn

Fields

name: String

if_exists: bool

drop column if exists — a missing column is a no-op instead of an error.

AddIndex

alter <Table> add index [if not exists] .<column> — creates a B+Tree index on column. No-op if the index already exists.

Fields

target: IndexTarget

if_not_exists: bool

Parsed for symmetry with the other DDL; add index is already idempotent, so this does not change behavior.

AddUnique

alter <Table> add unique [if not exists] .<column> — creates a UNIQUE B+Tree index on column. Scans existing data first and fails if any duplicate (non-null) value is present. Without if not exists it errors when the column is already indexed (no in-place upgrade); with it, an existing index is a no-op.

Fields

target: IndexTarget

if_not_exists: bool

DropIndex

alter <Table> drop index [if exists] <target> — removes either a stored-column index or an expression index with the exact path identity.

Fields

target: IndexTarget

if_exists: bool

AddLink

alter <Owner> add link <name> -> <Target> on <local> = <target>: declare a persistent entity link on the altered type. Lowers to Catalog::create_link; cardinality is derived there.

Fields

name: String

target: String

local_key: String

target_key: String

Trait Implementations

impl Clone for AlterAction

fn clone(&self) -> AlterAction

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for AlterAction

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

Formats the value using the given formatter.

impl PartialEq for AlterAction

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for AlterAction