Schematize

schematize is a node.js package that is an encapsulation of Sequelize and treble packages to handle 3 databases using external schema files.

Having access to 3 databases simultaneously and using external schemas and promise-like syntax permit to write business apps lot more easily.

To use schematize you should add schematize, sequelize, mysql and treble packages to your project.

How does it work?

    var db3 = require("treble")( Sequelize ,"mysql://login:password@host:port/webase");
    var schematize = require("schematize");

    schematize("admin","users",db3)
        .then( function(tUsers){ // success
             ...
            },
            function(){ // failor
                console.log("An error occured");
            }
        );

schematize is called with 3 parameters:

• db : database admin|modele|user.
• schema : Is the table name, described by a schema file
• db3 is a connection object created with treble package.

Where to put schemas ?

To configure the path where to find schema files, you should use one of the two syntaxes:

syntax 1:

    var schematize = require("schematize").config({path:__dirname+"/schemas/"})

In this case, schemas are in 3 subdirectories named "admin/","modele/","user/" from the specified path.

syntax 2:

    var schematize = schematize.config({path:{admin:__dirname+"/schemas/admin/", modele:__dirname+"/schemas/modele/",user:__dirname+"/schemas/user/"})

Example of content for users.js:

module.exports = function(DataTypes) {
  return ['users',{
     userID:{type:DataTypes.INTEGER, autoIncrement: true, allowNull: false, primaryKey:true},
     login:{type:DataTypes.STRING(25),  allowNull:false, unique:true},
     email:{type:DataTypes.STRING(150), allowNull:true,  unique:true, validate:{isEmail:true}},
     password:{type:DataTypes.STRING(50),allowNull:false},
    },
    {
     charset: 'utf8',
     collate: 'utf8_general_ci',
     comment:"Comprehensive list of all users"
    }];
}

The object given by the success handler offers the following methods:

• tUsers.find( {options}) -> promise,function
• tUsers.findAll( {options})
• tUsers.count( {options} )
• tUsers.update(values , where , fields)
• tUsers.destroy({where:{filter}})
• tUsers.create({values},[fields])

These methods are almost the same methods offered by sequelize. They can be managed using handlers:

• .success(handler)
• .error(handler)
• or a promise-like syntaxe .then( successHandler , errorHandler )

The success handler has a argument that is a function. Calling it permits to have the result data in an array or in an object directly.

Example

    var db3 = require("treble")( Sequelize ,"mysql://login:password@host:port/webase");
    var schematize = require("schematize");

    schematize("admin","users",db3)
        .then( function(tUsers){
            tUsers.findAll({limit:10}).then(
                    function(data){console.log("Users list:",data(["login","email"]));
                        console.log("Users list as an object:",data(["login","email"],"login"));
                        tUsers.create({login:'mylogin',password:'mypassword',email:'[email protected]'},['login','password','email']).then(
                            function(e){ 
                                console.log("New user inserted: ",e(['userID','login','password','email']));
                            },
                            function(){
                                console.log("User insertion failed..");
                            }
                        );
                    },
                    function(err){
                        console.log("Error reading data.");
                    });
            },
            function(e){
                console.log("Error when opening table.")
            }
        );

An other example with destroy:

    var db3 = require("treble")( Sequelize ,"mysql://login:password@host:port/webase");

    require("schematize")("admin","users",db3)
        .then( function(tUsers){
            tUsers.destroy({where:{userID:6}}).then(
                function(e){
                    console.log("destroy success.."));
                },
                function(e){
                    console.log("destroy fail!");
                });
            })

    }
}

Batch processing

When you have to open more than ONE table to do a task, you have to use the batch style of the command by giving an array as 'schema' argument. The succes event is fired when ALL the tables are opened. If ONE schema at least does not exist, an error is fired:

schematize("admin",["users","companies","databases"],db3)
    .then( function( tables ){
        tables.users.find( {login,"myLogin"}).then(
            function( oneLogin ){
                console.log( "User credencials: ",oneLogin(['login','password','email']) );
            },
            function(  ){
                console.log( "User not found!" );
            },
        )
    },
    function(tables){
        console.log("An error occured..");
    });

Force table drop

If you want to open one or more new tables and drop them if they already exist, you can add a 4th argument (force) for schematize(...) :

// tables dropped if exist
schematize("user",["products","custumers","bills"],db3,true)
    .then( function( tables ){
    }