Struct Migration 

pub struct Migration {
    pub id: String,
    pub app: Option<String>,
    pub dependencies: Vec<String>,
    pub operations: Vec<Operation>,
    pub atomic: bool,
    pub replaces: Vec<String>,
    pub checksum: String,
}

On-disk (and in-memory) migration.

id is a zero-padded sequence plus a slug (0001_initial). checksum is a 16-digit hex FNV-1a of the canonical JSON of id, dependencies, operations, atomic and replaces (the checksum field itself is excluded).

Fields

id: String

0001_initial.

app: Option<String>

Optional app label. Single-app projects leave this unset.

dependencies: Vec<String>

Ids of migrations that must be applied first.

operations: Vec<Operation>

Ordered operations.

atomic: bool

Wrap execution in a transaction when the backend supports it.

No effect on SQLite: the whole migrate/rollback run is already one transaction there (the lock), so a run is all-or-nothing. MySQL never wraps DDL regardless of this flag.

replaces: Vec<String>

Ids this squash replaces. The loader treats this migration as applied when every replaced id is in the history table.

checksum: String

Content checksum (see module docs).

Implementations

impl Migration

pub fn new( id: impl Into<String>, dependencies: Vec<String>, operations: Vec<Operation>, atomic: bool, replaces: Vec<String>, ) -> Result<Self, MigrationError>

Build a migration and fill in its checksum.

Errors

JSON encoding of the checksum body (does not fail for these types).

pub fn compute_checksum(&self) -> Result<String, MigrationError>

FNV-1a of the canonical checksum body.

Errors

JSON encoding failure.

pub fn refresh_checksum(&mut self) -> Result<(), MigrationError>

Refresh checksum from current fields.

Errors

JSON encoding failure.

pub fn is_irreversible(&self) -> bool

Whether any operation is unconditionally irreversible.

pub fn sequence(&self) -> Option<u32>

Leading sequence number from 0001_initial → 1. None if the id does not start with digits.

Trait Implementations

impl Clone for Migration

fn clone(&self) -> Migration

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Migration

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Migration

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for Migration

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for Migration

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Migration