Table of Contents

• Introduction
• Installation
• Apis
  • insert
  • update
  • query
  • beginTransaction
  • rollback
  • commit
• Promise support

Introduction

One of the duty of my job is to write web scraper -- scrape data and store to mysql tables. And most of the time, the origin tables are not created by myself. It's inefficient to model these tables like sequelize do. All I want is having direct access to the tables and being efficient. That's why I develop mysql-composer.

If you are looking for a more powerful tool, sequelize may be a better choice.

Installation

npm i -S mysql-composer

Apis

mysql-composer is a simple tool for you to execute sql on mysql database.

const Composer = require('mysql-composer')
const mysql = require('mysql')
const connection = mysql.createConnection({
      host     : 'localhost',
      user     : 'me',
      password : 'secret',
      database : 'my_db'
    });
const composer = new Composer(connection)

insert

insert(config,callback,inspect)

• config:

{
   table:'tableName', //require
   data:{ //require
         field1:'value1',
         field2:'value2'
       },
   ignore:true,//optional,defaults to true
   onDuplicateKeyUpdate:{field1:'value1',
   field2:function(){
        return 'field1+1'
    }},//optional 
}

• callback: will be called when sql is executed: callback(err,result)
• inspect: will be called with generated sql : inspect(sql)

example:

//insert ignore into user (`name`,`age`) values ('Tom','18')
composer.insert({
 table:'user',
 data:{
  name:'Tom',
  age:'18'
  }
},function(err,result){
  //your code after sql is executed
},function(sql){
    console.log(sql)
})

update

update(config,callback,inspect)

• config:

   {
      table:'tableName', //require
      data:{ //require
            field1:'value1',
            field2:function(){
                 return 'field2+1'
             }
          },
      where:'id=1' //require,if you need to update all, you should explicitly set 'where' to 1.
   }

• callback: will be called when sql is executed: callback(err,result)

• inspect: will be called with generated sql : inspect(sql)

example:

//update `user` set age='18' where id=1
composer.update({
 table:'user',
 data:{
  age:'18'
  },
 where:"id=1"
},function(err,result){
  //your code after sql is executed
},function(sql){
    console.log(sql)
})

query

query(sql,callback,inspect)

• sql: a valid sql syntax
• callback: will be called when sql is executed: callback(err,result)
• inspect: will be called with generated sql : inspect(sql)

example:

//update `user` set age='18' where id=1
composer.query('select * from user where id=1',function(err,result){
  //your code after sql is executed
},function(sql){
    console.log(sql)
})

beginTransaction

beginTransaction(callback)

• callback: will be called when beginTransaction is executed: callback(err)

example:

composer.beginTransaction(function(err){
    if(err)throw err
    composer.insert({
     table:'user',
     data:{
      name:'Tom',
      age:'18'
      }
    },function(err,result){
      if(err)return composer.rollback(function(){
        throw err
      })

      composer.commit(function(err){
         if(err)return composer.rollback(function(){
            throw err
         })

         console.log('success')
      })
    })
})

rollback

rollback(callback)

• callback: will be called when rollback is executed: callback(err)

commit

commit(callback)

• callback: will be called when commit is executed: callback(err)

Promise support

mysql-composer supports promise, it will be convenient if you like to use mysql-composer with co or async/await. if you do not provide a callback in the apis above, they will return a promise:

var promise = composer.update({
            table:'name',
            where:'id=2',
            data:{
                field1:'value1',
                field2:'value2'
            }
        })
promise.then(function(result){

}).catch(function(err){

})