mysql-dynamo

mysql-dynamo

A solution to use the simple-dynamo interface with a MySQL database. So you can create a offline version of a AWS-DynamoDB project.

Written in coffee-script

INFO: all examples are written in coffee-script

Install

  npm install mysql-dynamo

API differences to simple-dynamo

Compared to the simple-dynamo module you only have to make a few smears.

• Table-Config consistent not existes and will be ignored
• Table-Config overwriteExistingHash not exists. It always will NOT overwrite existing hashes
• Table-Config combineTableTo not exists. Within MySQL there is no need to save tables
• Table-Attribute-Config length The length of a field has to be defined
• Table-Attribute-Config default The SQL default of a field could be defined
• Item-Method-Options consistent not existes and will be ignored
• Item-Method-Options overwriteExistingHash not exists. It always will NOT overwrite existing hashes

One big difference between the Dynamo and MySQL version is that dynamo can generate undefined attributes on the fly. Th MySQL version will ignore undefined attributes. So all necessary attributes has to be defined within the table definitions

Connection and Table

Initialize

first you have to define the connection and table attributes and get an instance of the simple-dynamo interface.

new MySqlDynamo( connectionSettings, tables )

###connection Settings

---

• tablePrefix : ( String optional ) Option to prefix all generating tables

MySQL connection settings

• host : ( String required ) MySQL host
• user : ( String optional: default = root ) MySQL user
• password : ( String optional: default = secret ) MySQL password
• database : ( String optional: default = database ) Database name

###table Definition

An Object of Tables.
The key you are using will be the key to get the table object.

Every object can have the following keys:

• name : ( String required )
  Tablename for MySQL
• hashKey : ( String required )
  The hash key name of your ids/hashes
• hashKeyType : ( String optional: default = S )
  The type of the hashKey. Possible values are: S = String and N = Numeric
• hashKeyLength : ( Number optional: default = 5 for hashKeyType N and 255 for hashKeyType S )
  The table field length
• rangeKey: ( String optional )
  The range key name of your range attribute. If not defined the table will be generated without the range methods
• rangeKeyType: ( String optional: default = N )
  The type of the rangeKey. Possible values are: S = String and N = Numeric
• rangeKeyLength : ( Number optional: default = 5 for rangeKeyType N and 255 for rangeKeyType S )
  The table field length
• fnCreateHash: ( Function optional: default = new UUID )
  Method to generate a custom hash key.
• defaultfields: ( Array optional )
  List of fields to return as default. If nothing is defined all fields will be received. You always can overwrite this using options.fields.
  Method Arguments
  • attributes: The given attributes on create
  • cb: Callback method to pass the custom generates id/hash. cb( "my-special-hash" )
• fnCreateRange: ( Function optional: default = current Timestamp )
  Method to generate a custom range key.
  Method Arguments
  • attributes: The given attributes on create
  • cb: Callback method to pass the custom generates id/hash. cb( "my-special-range" )
• attributes: ( Array of Objects required )
  An array of attribute Objects. Which will be validated
  Attributes keys
  • key: ( String required )
    Column/Attribute name/key
  • type: ( String required )
    Datatype. possible values are string = String, number = Numeric and array = Array/Set of Strings
  • required: ( Boolean optional: default = false )
    Validate the attribute to be required. ( Not implemented yet ! )
  • length: ( Number optional: default = 255 )
    Lentgh of the MySQL DB Filed. If you combine type = string with a length= +Infinity the field will generated as type TEXT otherwise as VARCHAR( length ). If you define a number with a length > 11 a type BIGINT( length ) will be used. On a length <= 11 a type INT( length ) will be generated.
  • default ( String optional: default = `` )
    The SQL default value

Example

# import module
MySQLDynamo = require "mysql-dynamo"

# define connection settings
connectionSettings =
	host: "localhost"
	user: "root"
	password: "root"
	database: "myDB"
	
# define tables
tables = 
	"Users":
		name: "users"
		hashKey: "id"

		attributes: [
			{ key: "name", type: "string", required: true }
			{ key: "email", type: "string" }
		]
		
	"Todos":
		name: "todos"
		hashKey: "id"
		rangeKey: "_t"
		rangeKeyType: "N"
		
		fnCreateHash: ( attributes, cb )=>
			cb( attributes.user_id )
			return
		
		attributes: [
			{ key: "title", type: "string", required: true }
			{ key: "done", type: "number" }
		]

# create instance
sqldManager = new MySQLDynamo( connectionSettings, tables )

# connect
sqldManager.connect ( err )->
	console.log( "mysql-dynamo ready to use" )

First connect to MySQL

The module has to know about the existing SQL tables so you have to read them first.
If you do not run .connect() the module will throw an error everytime

Manager.connect( fnCallback ) Arguments :

• fnCallback: ( Function required )
  Callback method. Single arguments on return is the error object. On success the error is null

Example

sqldManager.connect ( err )->
	if err
		console.error( "connect ERROR", err )
	else
		console.log( "mysql-dynamo ready to use" )

Create all tables

to create all missing tables just call .createAll().

This is not necessary if you know the tables has been created in the past.

Manager.generateAll( fnCallback ) Arguments :

• fnCallback: ( Function required )
  Callback method. Single arguments on return is the error object. On success the error is null

Example

sqldManager.generateAll ( err )->
	if err
		console.error( "connect ERROR", err )
	else
		console.log( "mysql-dynamo ready to use" )

Get a table instance

To interact with a table you have to retrieve the table object. It's defined in the table-definitions

Manager.get( 'tableName' ) Arguments :

• tableName: ( String required )
  Method to retrieve the instance of a table object.

Example

tblTodos = sqldManager.get( 'Todos' )

Loop through all tables

Loop trough all table objects

Manager.each( eachFn ) Arguments :

• eachFn: ( Function required )
  Loop method call for every table object

Example

Manager.each ( tableKey, tableObj )=>
	console.log( "SQL table name", tableObj.tableName )
	return

Destroy a table

destroy table in MySQL. This drops a table from MySQL will all the data

Table.destroy( fnCallback ) Arguments :

• fnCallback: ( Function required )
  Callback method.
  Method Arguments
  • err: Usually null. On an error a object with error and msg

Example

tblTodos.del ( err )->
	if err
		console.error( "destroy ERROR", err )
	else
		console.log( "table destroyed" )

Item handling

Write a new item (INSERT)

Create a new item in a select table. You can also add some attributes not defined in the table-definition, which will be saved, too.

Table.set( data, options, fnCallback ) Arguments :

• data: ( Object required )
  The data to save. You can define the hash and/or range key. If not the module will generate a hash/range automatically.
  Note: If the used table uses the combined feature and you define the hash-key it's necessary to add the name out of the table-config in front of every hash.
• options: ( Object optional )
  • fields: ( Array ) An array of fields to receive
• fnCallback: ( Function required )
  Callback method.
  Method Arguments
  • err: Usually null. On an error a object with error and msg
  • item: the save item as simple object

Example

data = 
	title: "My First Todo"
	done: 0
	aditionalData: "Foo bar"
	
tblTodos.set data, ( err, todo )->
	if err
		console.error( "insert ERROR", err )
	else
		console.log( todo )

Get a item (GET)

Get an existing element by id/hash

Table.get( id[, options], fnCallback ) Arguments :

• id: ( String|Number|Array required )
  The id of an element. If the used table is a range table you have to use an array [hash,range] as combined id. Otherwise you will get an error.
• options: ( Object optional )
  • fields: ( Array ) An array of fields to receive. If nothing is defined all fields are returned.
• fnCallback: ( Function required )
  Callback method.
  Method Arguments
  • err: Usually null. On an error a object with error and msg
  • item: the database item as simple object. If not found null

Example

tblTodos.get 'myTodoId', ( err, todo )->
	if err
		console.error( "get ERROR", err )
	else
		console.log( todo )

tblRangeTodos.get [ 'myHash', 'myRange' ], ( err, todo )->
	if err
		console.error( "get ERROR", err )
	else
		console.log( todo )

Get many items (MGET)

Get an many existing elements by id/hash in one request

Table.mget( [ id1, id2, .. ], options, fnCallback ) Arguments :

• ids: ( Array required )
  An array of id of an elements. If the used table is a range table you have to use an array of arrays [hash,range] as combined id. Otherwise you will get an error.
• options: ( Object optional )
  • fields: ( Array ) An array of fields to receive. If nothing is defined all fields are returned.
• fnCallback: ( Function required )
  Callback method.
  Method Arguments
  • err: Usually null. On an error a object with error and msg
  • items: the database items as a array of simple objects. Only existing items will be received.

Example

tblTodos.mget [ 'myTodoIdA', 'myTodoIdB' ], ( err, todos )->
	if err
		console.error( "get ERROR", err )
	else
		console.log( todos )

tblRangeTodos.mget [ [ 'myHash', 1 ], [ 'myHash', 2 ] ], ( err, todos )->
	if err
		console.error( "get ERROR", err )
	else
		console.log( todos )

Update an item (UPDATE)

update an existing item. If you try to update a not existing item it will be created. To remove a attribute you have to set the value to null

Table.set( id, data, options, fnCallback ) Arguments :

• id: ( String|Number|Array required )
  The id of an element. If the used table is a range table you have to use an array [hash,range] as combined id. Otherwise you will get an error.
• data: ( Object required )
  The data to update. You can redefine the range key. If you pass the hash key it will be ignored
• options: ( Object optional )
  For update you can define some options.
  • fields: ( Array ) An array of fields to receive
  • conditionals ( Object ) A query object to define a conditional. Only {"==": value}, {"==": null}, and {"!=": null} are allowed. How to build? … have a look at Jed's Predicates
• fnCallback: ( Function required )
  Callback method.
  Method Arguments
  • err: Usually null. On an error a object with error and msg
  • item: the database item as simple object. If not found null

Example

data = 
	title: "My First Update"
	done: 1
	
tblTodos.set 'myTodoId', data, ( err, todo )->
	if err
		console.error( "update ERROR", err )
	else
		# note. the key 'aditionalData' will be gone
		console.log( todo )

Delete an item (DELETE)

delete an item by id/hash

Table.del( id, fnCallback ) Arguments :

• id: ( String|Number|Array required )
  The id of an element. If the used table is a range table you have to use an array [hash,range] as combined id. Otherwise you will get an error.
• fnCallback: ( Function required )
  Callback method.
  Method Arguments
  • err: Usually null. On an error a object with error and msg

Example

tblTodos.del 'myTodoId', ( err )->
	if err
		console.error( "delete ERROR", err )
	else
		console.log( "delete done" )

Query a table (FIND)

run a query on a table. The module automatically trys to do a Dynamo.db scan or Dynamo query.

Table.find( query, startAt, options, fnCallback ) Arguments :

• query: ( Object : default = {} all )
  A query object. How to build … have a look at Jed's Predicates
• startAt: ( String|Number|Array optional )
  To realize a paging you can define a startAt. Usually the last item of a list. If you define startAt with the last item of the previous find you get the next collection of items without the given startAt item.
  If the used table is a range table you have to use an array [hash,range] as combined startAt. Otherwise you will get an error.
• options: ( Object optional )
  • fields: ( Array ) An array of fields to receive
  • limit: ( Number ) Define the max. items to return
  • forward: ( Boolean default = true ) define the direction acs or desc for range querys.
• fnCallback: ( Function required )
  Callback method.
  Method Arguments
  • err: Usually null. On an error a object with error and msg
  • items: an array of objects found

Example

tblTodos.find {}, ( err, items )->
	if err
		console.error( "delete ERROR", err )
	else
		console.log( "all existend items", items )

Advanced Examples

# create a query to read all todos from last hour
_query = 
	id: { "!=": null }
	_t: { "<": ( Date.now() - ( 1000 * 60 * 60 ) ) }

tblTodos.find , ( err, items )->
	if err
		console.error( "delete ERROR", err )
	else
		console.log( "found items", items )

# read 4 todos from last hour beginning starting with a known id
_query = 
	id: { "!=": null }
	_t: { "<": ( Date.now() - ( 1000 * 60 * 60 ) ) }

_startAt = "myid_todoItem12"

_options = { "limit": 4, "fields": [ "id", "_t", "title" ] }

tblTodos.find _query, _startAt, _options, ( err, items )->
	if err
		console.error( "delete ERROR", err )
	else
		console.log( "4 found items", items )

Numeric functions

If a field is defined as number you can run simple operations like increase and decrese the value.

To do this you can pass the value of a number as

• "key": { "$add": 1 } to increase the number by 1
• "key": { "$rem": 1 } to decrease the number by 1
• "key": { "$reset": 1 } to set the number by 1

Working with sets

Dynamo has the ability to work with sets. That means you can save a Set of Strings as an Array.
During an update you have the ability to add or remove a single value out of the set. Or you can reset the whole set.

But you can only perform one action per key and you only can use the functionality if defined through the table-definition ( type:"array" ).

Existing values will be ignored.

The following key variants are available:

• "key":[ "a", "b", "c" ]': Resets the whole value of the key
• "key":{ "$add": [ "d", "e" ] }: Add some values to the set
• "key":{ "$rem": [ "a", "b" ] }: remove some values
• "key":{ "$reset": [ "x", "y" ] }: reset the whole value. Same as "key":[ "x", "y" ]'
• "key":{ "$add": "d"}: Add a single value to the set
• "key":{ "$rem": "a" }: remove a single value
• "key":{ "$reset": "y" }: reset the whole set to a single value. Same as "key":[ "y" ]'

Examples

# Source "key: [ "a", "b", "c" ]"

data = 
    key: [ "x", "y", "z" ]

tblSets.set 'mySetsId', data, ( err, setData )->
    # Result "key: [ "x", "y", "z" ]"
    console.log( setData )

# Source "key: [ "a", "b", "c" ]"

data = 
    key: { "$add": [ "a", "d", "e" ] }

tblSets.set 'mySetsId', data, ( err, setData )->
    # Result "key: [ "a", "b", "c", "d", "e" ]"
    console.log( setData )

# Source "key: [ "a", "b", "c" ]"

data = 
    key: { "$rem": [ "a", "b", "x" ] }

tblSets.set 'mySetsId', data, ( err, setData )->
    # Result "key: [ "c" ]"
    console.log( setData )

# Source "key: [ "a", "b", "c" ]"

data = 
    key: { "$reset": [ "x", "y", "z" ] }

tblSets.set 'mySetsId', data, ( err, setData )->
    # Result "key: [ "x", "y", "z" ]"
    console.log( setData )

#Events

To provide a API to react on different events you can listen to a bunch of events.

##Manager Events

• new-table: Table object initialized and ready to use. This means only the client model is ready. Eventually you have to create the table first.
  Event Arguments
  • name: the name og the table, like you would use with `Manager.get()
  • Table: the Table object
• table-generated: Fired after all a new tables has been generated. Event Arguments
  • Meta: the tables meta-data
• all-tables-generated: Fired after all tables are generated.

##Table Events

• create-status: fired on table create.
  Event Arguments
  • status: describes the state of table creation. Possible values are: already-active, waiting, active
• get: fired after a table.get.
  Event Arguments
  • item: the item
• get-empty: fired after a table.get with an empty result.
• mget: fired after a table.mget.
  Event Arguments
  • items: the items
• mget-empty: fired after a table.mget with no results.
• create: fired after a item has been created.
  Event Arguments
  • item: the created item
• update: fired after a item has been updated.
  Event Arguments
  • item_new: the item after the update
• delete: fired after a item has been deleted.
  Event Arguments
  • item_old: the item before the delete

Changelogs

0.3.3 16. Sep. 2014

Fixed delete to return the correct data;

0.3.2 5. Sep. 2014

Small fix for escaping the keys; fixes for current dependencies;

0.3.1 07. May 2014

• Bugfix to be able to use reserved words like key as fieldnames

0.3.0 15. April 2014

• Do a insert during update for a simple set call. This has been done due to compatibility to dynamo db.

0.2.7 18. Okt. 2013

• Bugfix adding combineTableTo fields to tablename if it's defined

0.2.6 18. Okt. 2013

• Bugfix converting data

0.2.5 14. Okt. 2013

• Feature: added numeric functions feature

0.2.4 14. Okt. 2013

• Bugfix: Fixed like search and changed due to mysql alpha release 9

0.2.2 7. June 2013

• Bugfix: order by field and startAt for reverse order

0.2.2 7. June 2013

• Updated readme
• generated the code docs

0.2.1 7. June 2013

• Added missing destroy table
• Print a a warning on table destroy and table create

0.2.0 7. June 2013

• Added manager/table option tablePrefix to prefix the sql table names
• added manager method .each()
• Changed tests to drop the tables before test

0.1.4 6. June 2013

• Print out a warning if attributes are removed by the validation

0.1.3 6. June 2013

• Fixed package json to use the correct mysql-node version if an older version is already used within the project

0.1.2 6. June 2013

• Added code docs with docker
• Some small code improvements

0.1.1 6. June 2013

• Added Readme

0.1.0 5. June 2013

• Initial version

Todos

• better validation of the given config-data

Work in progress

mysql-dynamo is work in progress. Your ideas, suggestions etc. are very welcome.

License

(The MIT License)

Copyright (c) 2010 TCS <dev (at) tcs.de>

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.