Database migration tool
This is used to keep track of the database structure, content etc, and update it when need be via deploys.
Supported databases:
- MariaDB (and MySQL)
- Elasticsearch
A table/index by default called db_version will be created, containing a single integer.
Scripts will be placed by default in process.cwd()/dbmigration/.js
Each migration script will be ran, and the db_version increased, until no more migration scripts exists.
Installation
npm i --save larvitdbmigration
Usage
Application startup script
In your application startup script, do something like this:
MariaDb and MySQL
'use strict';
const DbMigration = require('larvitdbmigration');
const options = {};
const winston = require('winston');
const log = winston.createLogger({'transports': [new winston.transports.Console()]});
const db = require('larvitdb');
let dbMigration;
db.setup({
'host': '127.0.0.1',
'user': 'foo',
'password': 'bar',
'database': 'baz'
});
options.dbType = 'mariadb';
options.dbDriver = db;
options.tableName = 'db_version';
options.migrationScriptsPath = './dbmigration';
options.log = log;
dbMigration = new DbMigration(options);
dbMigration.run(function (err) {
if (err) throw err;
});
Elasticsearch
'use strict';
const DbMigration = require('larvitdbmigration');
const options = {};
const winston = require('winston');
const log = winston.createLogger({'transports': [new winston.transports.Console()]});
let dbMigration;
options.dbType = 'elasticsearch';
options.url = 'http://127.0.0.1:9200';
options.indexName = 'db_version';
options.migrationScriptsPath = './dbmigration';
options.log = log;
dbMigration = new DbMigration(options);
dbMigration.run(function (err) {
if (err) throw err;
});
Example migration scripts
Lets say the current database have a table like this:
CREATE TABLE bloj (nisse int(11));
And in the next deploy we'd like to change the column name "nisse" to "hasse". For this you can do one of two methods:
MariaDB / MySQL, Javascript
Create the file process.cwd()/migrationScriptsPath/1.js with this content:
'use strict';
exports = module.exports = function (cb) {
const db = this.options.dbDriver;
db.query('ALTER TABLE bloj CHANGE nisse hasse int(11);', cb);
};
Elasticsearch
Create the file process.cwd()/migrationScriptsPath/1.js with this content:
'use strict';
const request = require('request');
exports = module.exports = function (cb) {
const that = this;
request({
'url': that.options.url + '/some_index/_mapping/some_type',
'json': true,
'method': 'PUT',
'body': {
'properties': {
'names': {
'type': 'string',
'position_increment_gap': 100
}
}
}
}, cb);
};
SQL
IMPORTANT! SQL files will be ignored if a .js file exists.
Create the file process.cwd()/migrationScriptsPath/1.sql with this content:
ALTER TABLE bloj CHANGE nisse hasse int(11);
Summary
Tadaaa! Now this gets done once and the version will be bumped to 1. If you then create a script named "2.js" or "2.sql" you might guess what happends. :)