Enum Operation 

pub enum Operation {
    CreateModel {
        model: ModelState,
    },
    DeleteModel {
        name: String,
    },
    RenameModel {
        old_name: String,
        new_name: String,
        table: String,
    },
    AddField {
        model: String,
        field: FieldState,
    },
    RemoveField {
        model: String,
        name: String,
    },
    AlterField {
        model: String,
        name: String,
        field: FieldState,
    },
    RenameField {
        model: String,
        old_name: String,
        new_name: String,
    },
    CreateIndex {
        model: String,
        index: IndexState,
    },
    DeleteIndex {
        model: String,
        name: String,
    },
    AddConstraint {
        model: String,
        constraint: ConstraintState,
    },
    DeleteConstraint {
        model: String,
        name: String,
    },
    RunSQL {
        sql: String,
        reverse_sql: Option<String>,
    },
    RunRust {
        name: String,
        backwards: Option<String>,
    },
}

One atomic schema change (or a data operation).

RunSQL without reverse_sql and RunRust without backwards are irreversible. DeleteModel and RemoveField reverse by recreating the object from state_before.

Variants

CreateModel

Create a table (and its indexes / table constraints).

Fields

model: ModelState

Full model snapshot after the create.

DeleteModel

Drop a table.

Fields

name: String

Model name.

RenameModel

Rename a model (and its table when table differs from the current table). Detected only when listed in crate::autodetector::RenameHints.

Fields

old_name: String

Current model name.

new_name: String

New model name.

table: String

Table name after the rename.

AddField

Add a column.

Fields

model: String

Model name.

field: FieldState

New field.

RemoveField

Drop a column.

Fields

model: String

Model name.

name: String

Field name.

AlterField

Replace a field’s schema (type, nullability, default, …).

Fields

model: String

Model name.

name: String

Field name (after any rename in the same migration).

field: FieldState

New field snapshot.

RenameField

Rename a field. Detected only when listed in crate::autodetector::RenameHints; otherwise a same-shape remove+add is refused.

Fields

model: String

Model name.

old_name: String

Current field name.

new_name: String

New field name. The column is renamed when it currently equals old_name.

CreateIndex

Create a named index.

Fields

model: String

Model name.

index: IndexState

Index snapshot.

DeleteIndex

Drop a named index.

Fields

model: String

Model name.

name: String

Index name.

AddConstraint

Add a table-level constraint.

Fields

model: String

Model name.

constraint: ConstraintState

Constraint snapshot.

DeleteConstraint

Drop a table-level constraint.

Fields

model: String

Model name.

name: String

Constraint name.

RunSQL

Developer-authored SQL. Irreversible unless reverse_sql is set.

Fields

sql: String

Forward SQL (may contain several statements).

reverse_sql: Option<String>

SQL that undoes sql.

RunRust

A function registered at runtime in a crate::registry::MigrationRegistry. The function itself cannot be serialized; only the name is stored.

Fields

name: String

Registered forward name.

backwards: Option<String>

Registered backwards name, if reversible.

Implementations

impl Operation

pub fn apply_to_state( &self, state: &mut ProjectState, ) -> Result<(), MigrationError>

Apply this operation to state.

Errors

MigrationError::State when a referenced model or field is missing, or when creating a duplicate.

pub fn reverse(&self, state_before: &ProjectState) -> Option<Operation>

Inverse operation, or None if this step is irreversible.

state_before is the project state immediately before this operation was applied. DeleteModel and RemoveField recreate the dropped object from it.

pub fn is_unconditionally_irreversible(&self) -> bool

Whether reversal is impossible regardless of project state (RunSQL without reverse_sql, RunRust without backwards).

pub fn summary(&self) -> String

Short label for CLI output (CreateModel Author).

Trait Implementations

impl Clone for Operation

fn clone(&self) -> Operation

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Operation

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Operation

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for Operation

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for Operation

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 Operation