I'm sure you know know how to install packages but here is the command for the sake of completeness
npm install sequelize async
First initilize the migrations structure
sequelize --init
Then create the initial migration, but dont edit this file as we will use it create the SequelizeMeta
table.
sequelize -c initial
Create another migration
sequelize -c create-tables
Now dump your database without the data. With mysqldump
mysqldump -d --compact --compatible=mysql323 ${dbname}|egrep -v "(^SET|^/\*\!)"
.
We need to remove the `SET
Save this dump to the migrations folder and name it intial.sql
Edit the last migration that was created to look like;
var async = require('async')
, fs = require('fs');
module.exports = {
up: function(migration, DataTypes, done) {
var db = migration.migrator.sequelize;
async.waterfall([
function(cb){
fs.readFile(__dirname + '/initial.sql', function(err, data){
if (err) throw err;
cb(null, data.toString());
});
},
function(initialSchema, cb){
// need to split on ';' to get the individual CREATE TABLE sql
// as db.query can execute on query at a time
var tables = initialSchema.split(';');
function createTable(tableSql, doneInsert){
db.query(tableSql);
}
async.each(tables, createTable, cb);
}
], done);
},
down: function(migration, DataTypes, done) {
migration.showAllTables().success(function(tableNames){
// Dont drop the SequelizeMeta table
var tables = tableNames.filter(function(name){
return name.toLowerCase() !== 'sequelizemeta';
});
function dropTable(tableName, cb){
migration.dropTable(tableName);
cb();
}
async.each(tables, dropTable, done);
});
}
}
On the migrations up
function we use async.waterfall
to orchestrate a the async calls;
- read in the
initial.sql
file - need to split the
initial.sql
and retrieve eachCREATE TABLE
queries asdb.query
can execute on query at a time - using
async.each
run each of these queries
On the migrations down
function we just remove all tables that is not the SequelizeMeta
table. For some reason migration.dropAllTables()
remove this table and messes up the migrations. Not sure if this is the correct behavior.
@fedikhatib that is surprising that it's working in 2024 ! I haven't even used Sequelize since this was written.