Dartabase Migration 0.4.3

Serverside Database migration for simple version controlled database structure manipulation

now possible to combine the power of Dartabase Model and Dartabase Migration

inspired by Ruby on Rails migrations

Version
	0.4.3 -fixed crash when projectsMapping.json does not exist on dbInit.dart
	0.4.2 -adapted column option to support old migration files
		   migrations now support '"column" : "INT"' and '"column" : {"type":"INT"}'
	0.4.1 -added column options 'default' and 'null'
		   see "COLUMN OPTIONS"
	0.4.0 -small breaking change -> added posibility for column options
	0.3.0 -breaking change -> added autogenerated created_at and updated_at 
	       see "COLUMN CREATED/UPDATED" info below
	0.2.0 -breaking change -> added autogenerated id 
	       see "COLUMN ID" info below 
    0.1.0 -updated for Dart 1.0, restructured code for use with Dartabase Models
	0.0.5 -adapted breaking changes due to dart:encoder

Tested on 
	Dart Editor version 1.0.1_r30657 (DEV)
	Dart SDK version 1.0.1.3_r30657
	
compatibility
	depending on the migration version you are using 
	you have to use a differend model version in your app
    
    migration  			model
    -------------------------
    0.4.x	requires    0.4.x
    0.3.0	requires	0.3.0 deprecated!!
	

Uses

MYSQL via sqljocky version 0.9.0

PGSQL via postgresql version 0.2.12

HOW TO SETUP

USE THIS INSTALL GUIDE AND IGNORE THE INSTALL PAGE!!! This is a stand alone app!

1.Download dartabase_migration somewhere on your drive

  now run 'Pub Get' on dartabase_migration/pubspec.yaml

2.Execute dartabase_migration/bin/dbInit.dart

  to initiate the dartabase_migration tool for your project.

3.follow the instructions

  *enter a project name
  *enter path to project root folder

4.dartabase_migration will create files and folders below to do its magic

  *dartabase_migration/bin/projectsMapping.json       
  	-maps project names to absolute project path
  *$yourProjectName/db/
  *$yourProjectName/db/config.json          
    -dartabase config file to connect IP/PORT/DBType
  *$yourProjectName/db/schema.json          
    -current dartabase_migration structure as JSON used by Dartabase tools
  *$yourProjectName/db/schemaVersion.json   
    -safes name of latest migrated version
  *$yourProjectName/db/migrations           
    -folder for your database migration files

5.Edit the *$yourProjectName/db/config.json file so dartabase_migration can connect to your existing database.

eg.
--------config.json---------
{
    "adapter": "MySQL",
    "database": "dbName",
    "username": "dbUsername",
    "password": "dbPassword",
    "host": "localhost",
    "port": "3306"
}
----------------------------

for postgresql use

"adapter": "PGSQL"    (all capital)

HOW TO UPDATE DARTABASE MIGRATION

GENEREL UPDATE

it is important to keep 'dartabase_migration/bin/projectsMapping.json' but since this file will be autogenerated only on initiation of dartabase migration, there should not be a problem.

	1.download the new version of dartabase migration 
	
	2.replace all files from your current running version 
	  (but not projectsMapping.json)
	

LOST 'projectsMapping.json' DONT PAN!C

	1.create a file named projectsMapping.json inside 'dartabase_migration/bin/'
	  
	  inside the file enter a json key value pair of a projectname of your choice
	  
        keys    : project_names (your choice/short is good ;)
        values  : project absolute project path
	  
	  eg.
	  {
	     "mysql":"C:\\myServer",
	     "pgsql":"C:\\pgServer"
	  }

MOVED/RENAMED project

	Rename the values when moving/renaming one of your projects
	  

now you should be able to find your projects again when running dbUp or dbDown

UPDATE TO VERSION 0.2.0

	If you had already created a migration file with a comuln 'id' in version < 0.2.0 
	remove the entry for 'id' from all your migration file UP and DOWN hashes
	
	    

HOW TO CREATE MIGRATIONS

Either

1a.execute dartabase_migration/bin/createMigration.dart and follow the instructions

*enter project name
*enter migration name eg. "create_table_user"

it will create a dummy migration inside

"$yourProjectName/db/migrations/YYYYMMTTHHMMSS_create_table_user" 

or

1b.Create a migration json file "timestamp_action.json"

inside "$yourProjectName/db/migrations"

eg. "$yourProjectName/db/migrations/20130709134700_create_table_user.json"

2.inside your migration file you have a fixed structure!

a JSON object with a key "UP" and a json object value

to use migrations you can specify 4 keys/actions inside the "UP" value

createTable

"createTable" key takes a json object as value

    keys    : non_existent_table_names
    values  : json object
                keys    : non_existent_column_names
                values  : DARTABASETYPE
                		  or
                		  json object
                			keys: column options 
                			values: column option values 

	type only
	"createTable": {
		"new_table_name_one": {
			"new_column_name": "DATATYPE"
			}
		}
		
    or with options					
    "createTable": { 					
        "new_table_name_one": {				
            "new_column_name": {			    
            	'type':"DATATYPE",			
                'default':"1234"		
            }								
        }								
    }

createColumn

"createColumn" key takes a json object as value

    keys    : existing_table_names
    values  : json object
                keys    : non_existent_column_names
                values  : DARTABASETYPE
                		  or
                		  json object
                			keys: column options 
                			values: column option values 

	type only
	"createColumn": {
		"existing_table_name_one": {
			"new_column_name": "DATATYPE"
			}
		}
    
    or with options
    "createColumn": {					
        "existing_table_name_one": {		
            "new_column_name": {				 
            	'type':"DATATYPE"			
            }							
        }
    }

removeColumn

"removeColumn" key takes a json object as value

    keys    : existing_table_names
    values  : array[existing_column_names]

    eg.
    "removeColumn": {
        "existing_table_name_one": ["existing_column_name_one"]
    }

removeTable

"removeTable" key takes array of existing_table_names

    eg.
    "removeTable": ["existing_table_name_one"]

A simple migration could look like

----------20130709134700_create_table_user.json--------------
{
    "UP": {
        "createTable": {
            "user": {
                "name": "VARCHAR"
            }
        }
    },
    "DOWN": {
        "removeTable": ["user"]
    }
}

We create a table named "user" with column "name" and datatype "variable length of characters"


COLUMN ID

The 'id' column will be generated by 'Dartabase Migration' for every table as primary key.

Dont add 'id' in any of the migration files.

This is to let 'Dartabase Model' decide when to create or update an Object on save() - see Dartabase Model


COLUMN CREATED/UPDATED

For each table a created_at and updated_at column will be generated automatically.

created_at 
  will only be set to current datetime on creation of table row entry 

updated_at 
  will be set to current datetime on creation of table row entry
  PGSQL
    will be updated when the row has been saved
  MySQL
    will be updated when the row has been saved and a value of the row changed 
		 

COLUMN OPTIONS

following options are awailable for columns

option			values			
"type"		->	"DARTABASETYPE" 	<---always needed
"default"	->	"yourDefaultValue"	<---optional 
"null" 		-> 	"true" or "false"   <---optional 

if options are not set then it should use dbAdapter standart settings

example

"createColumn": {
    "player": {
        "player_name": {
        	'type':"VARCHAR",
        	'null':"false",
        	'default':"unnamed Player"
        }
    }
}

UP AND DOWN

Additionally to the "UP" key you can specify all actions inside the "DOWN" key

actions inside "UP" are executed during migration
actions inside "DOWN" are executed when reverting migrations

since we created a table named "user", we might want to remove it once we want to revert the migration

!!!ATTENTION be sure your don't need the data inside a table/column 
before you remove it!!!

ORDER OF EXECUTION

Once you have more than one action in the migration file

eg.
  adding a column
  adding a table
  removing a column

remember that the order of execution inside a migration will be

createTable
    ->
    createColumn
        ->
        removeColumn
            ->
            removeTable

but I cant think of a feasible example where that might bring up problems.


HOW TO RUN MIGRATIONS

1.Execute dartabase_migration/bin/dbUp.dart

2.Follow instructions in console

    *enter project name
    *enter goal migration version

dartabase_migration should have executed the actions specified inside the "UP" key for all files INCLUDING the goal migration version.

Additionally it will update

*$yourProjectName/db/schema.json
with the current database structure as JSON

*$yourProjectName/db/schemaVersion.json
with the name of latest migrated migration file

HOW TO REVERT MIGRATIONS

1.Execute dartabase_migration/bin/dbDown.dart

2.Follow instructions in console

*enter project name
*enter goal migration version 

dartabase_migration should have executed the actions specified inside the "DOWN" key for all files EXCLUDING the goal migration version.

Additionally it will update

*$yourProjectName/db/schema.json
with the current database structure as JSON

*$yourProjectName/db/schemaVersion.json
with the name of latest migrated migration file

DARTABASE DATA TYPES

dartabase_migration types are Specified in capitals.

on the left hand you see the dartabase_migration data type name on the right the data type your database will use

MYSQL

{
    "BINT": "BIGINT",
    "BINT UNSIGNED": "BIGINT UNSIGNED",
    "BINARY": "BINARY",
    "BIT": "BIT",
    "BLOB": "BLOB",
    "BOOLEAN": "BOOLEAN",
    "BYTEARRAY": "BLOB",
    "CHAR": "CHAR(255)",
    "DATE": "DATE",
    "DATETIME": "DATETIME",
    "DOUBLE": "DOUBLE",
    "FLOAT": "FLOAT(2)",
    "FLOAT UNSIGNED": "FLOAT(2) UNSIGNED",
    "INT": "INT",
    "INT": "INT",
    "INT UNSIGNED": "INT UNSIGNED",
    "LBLOB": "LONGBLOB",
    "LTEXT": "LONGTEXT",
    "MBLOB": "MEDIUMBLOB",
    "MINT": "MEDIUMINT",
    "MINT UNSIGNED": "MEDIUMINT UNSIGNED",
    "MTEXT": "MEDIUMTEXT",
    "SINT": "SMALLINT",
    "SINT UNSIGNED": "SMALLINT UNSIGNED",
    "TEXT": "TEXT",
    "TIME": "TIME",
    "TIMESTAMP": "TIMESTAMP",
    "TBLOB": "TINYBLOB",
    "TINT": "TINYINT",
    "TINT UNSIGNED": "TINYINT UNSIGNED",
    "TTEXT": "TINYTEXT",
    "VARBINARY": "VARBINARY(255)",
    "VARCHAR": "VARCHAR(255)"
}

PGSQL

{
    "BINT": "bigint",
    "BINT UNSIGNED": "numeric(20)",
    "BINARY": "bytea",
    "BIT": "bytea",
    "BLOB": "bytea",
    "BOOLEAN": "boolean",
    "BYTEARRAY": "bytea",
    "CHAR": "char(255)",
    "DATE": "date",
    "DATETIME": "timestamp",
    "DOUBLE": "double precision",
    "FLOAT": "real",
    "FLOAT UNSIGNED": "real",
    "INT": "integer",
    "INT UNSIGNED": "bigint",
    "LBLOB": "bytea",
    "LTEXT": "text",
    "MBLOB": "bytea",
    "MINT": "integer",
    "MINT UNSIGNED": "integer",
    "MTEXT": "text",
    "SINT": "smallint",
    "SINT UNSIGNED": "integer",
    "TEXT": "text",
    "TIME": "time",
    "TIMESTAMP": "timestamp",
    "TBLOB": "bytea",
    "TINT": "smallint",
    "TINT UNSIGNED": "smallint",
    "TTEXT": "text",
    "VARBINARY": "bytea",
    "VARCHAR": "varchar(255)"
}

Now you can add migration files for simple database manipulation

TODO

*fix async outputtext
*workarround for database problems with reserved words 
 on creation or when switching DBAdapter from PG to MY.
    eg. table name 'user' will break in MySQL
    fix -> add '_' as prefix to all column and table names
*test on other systems
*adding rename action
*adding option to specify variable length
    currently VARCHAR fix at 255
*test functionality of all data types
*improvements, adapt more functionality from db connectors
*and much more

Please let me know about bugs you find and or improvements/features you would like to see in future.

ENJOY & BE NICE ;)

Libraries

dartabase_migration