SequelizeJava - ORM for PostgreSQL

Simplicity of sequelize from NodeJS to Java.

• Creating instance of Sequelize:

import sequelize.Sequelize;

Sequelize sequelize = new Sequelize("DBNAME", "USER","PASSWORD");

• Creating Schema for your Model:

import sequelize.model.Schema;

Schema UserSchema = new Schema()
                        .withUpdatedAt() // It will create `updatedAt` timestamp to control the date of last update
                        .withCreatedAt() // It will create `createdAt` timestamp to control the date of creation
                        .insert("name", DataTypes.TEXT)
                        .insert("surname", DataTypes.TEXT);

Schema is like table in Postgres. You should describe columns you need in Schema.

• Connect your Schema with database and create Model:

import sequelize.model.Model;

Model User = sequelize.define("User", UserSchema);

Here you say to Sequelize that in table User there are data in UserSchema format.

• Sync your models with database:

sequelize.sync();

This method will delete all tables with each model name if it exists and create them back with columns from Model Schema

Model:

Method	Returns
.create(SchemaValues)	CompletedFuture
.findAll(Statement)	CompletedFuture
.findOne(Statement)	CompletedFuture
.update(SchemaValues, Statement)	CompletedFuture
.delete(Statement)	CompletedFuture

Statement:

Method	Example	SQL
.where(String columnName, Operator op, Object obj)	.where("id", Operator.eq, 1)	... WHERE id = 1
.and()	.where("id",Operator.gt,1) .and() .where("id",Operator.lt, 10)	... WHERE id > 1 AND id < 10
.or()	.where("id",Operator.gt,1) .or() .where("id",Operator.lt, 10)	... WHERE id > 1 OR id < 10
.setAttributes(List attributes)	.setAttributes(Arrays.asList("id","name"))	SELECT "id","name" ...

Schema:

Method	Example
.insert(String name, DataTypes type)	.insert("name", DataTypes.TEXT)
.withCreatedAt()
.withUpdatedAt()