Struct barrel::migration::Migration

pub struct Migration { /* fields omitted */ }

Represents a schema migration on a database

Methods

impl Migration

pub fn new() -> Migration

pub fn schema<S: Into<String>>(self, schema: S) -> Migration

Specify a database schema name for this migration

pub fn make<T: SqlGenerator>(&self) -> String

Creates the SQL for this migration for a specific backend

This function copies state and does not touch the original migration layout. This allows you to call revert later on in the process to auto-infer the down-behaviour

pub fn make_from(&self, variant: SqlVariant) -> String

The same as make but making a run-time check for sql variant

The SqlVariant type is populated based on the backends that are being selected at compile-time.

This function panics if the provided variant is empty!

pub fn revert<T: SqlGenerator>(&self) -> String

Automatically infer the down step of this migration

Will thrown an error if behaviour is ambiguous or not possible to infer (e.g. revert a drop_table)

pub fn execute<S: SqlGenerator, T: SqlRunner>(&self, runner: &mut T)

Pass a reference to a migration toolkit runner which will automatically generate and execute

pub fn create_table<S: Into<String>, F: 'static>(
    &mut self,
    name: S,
    cb: F
) -> &mut TableMeta where
    F: Fn(&mut Table), 

Create a new table with a specific name

pub fn create_table_if_not_exists<S: Into<String>, F: 'static>(
    &mut self,
    name: S,
    cb: F
) -> &mut TableMeta where
    F: Fn(&mut Table), 

Create a new table only if it doesn't exist yet

pub fn change_table<S: Into<String>, F: 'static>(&mut self, name: S, cb: F) where
    F: Fn(&mut Table), 

Change fields on an existing table

pub fn rename_table<S: Into<String>>(&mut self, old: S, new: S)

Rename a table

pub fn drop_table<S: Into<String>>(&mut self, name: S)

Drop an existing table

pub fn drop_table_if_exists<S: Into<String>>(&mut self, name: S)

Only drop a table if it exists