Struct EmbeddedMigration 

pub struct EmbeddedMigration<'a> {
    pub name: &'a str,
    pub sql: &'a str,
    pub hash: &'a str,
}

One migration whose SQL is resolved at compile time, usually by include_str!.

A single-binary distribution — cargo install, a tap, a curl | sh installer — has no migrations directory on the target machine, so the bytes have to travel inside the executable:

const MIGRATIONS: &[EmbeddedMigration] = &[EmbeddedMigration {
  name: "0001_init.sql",
  sql: include_str!("../migrations/0001_init.sql"),
  hash: "sha256:2c8f…",
}];

Baking the SQL in does not weaken the integrity check, it strengthens it: on disk the file can be edited after install, whereas here verify_hash turns an edit to a shipped .sql into a failing test in the project that ships it.

Fields

name: &'a str

Recorded in _migrations.name, and how an already-applied migration is recognized. Conventionally the file name, e.g. "0001_init.sql", so a project can move between this and run_migrate.

sql: &'a str

The migration’s SQL. Several statements separate with --> statement-breakpoint, exactly as in a generated file.

hash: &'a str

The expected SHA-256 of sql, as "sha256:…" — the same string _journal.json carries for this migration.

Implementations

impl EmbeddedMigration<'_>

pub fn verify_hash(&self) -> Result<(), MigrateError>

Checks sql against hash without touching a database, so a project can assert its whole list in one #[test].

Errors

Returns MigrateError::HashMismatch when the two disagree.