Dartabase Migration 0.1.0

Serverside Database migration for simple version controlled database structure manipulation 
inspired by Ruby on Rails migrations

Version
    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 0.8.10_r30104 (DEV)
    Dart SDK version 0.8.10.10_r30104
	
Uses
	MYSQL via http://pub.dartlang.org/packages/sqljocky version 0.7.0
	PGSQL via http://pub.dartlang.org/packages/postgresql version 0.2.11

HOW TO SETUP

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

1.Download dartabase_migration somewhere on your drive and 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 needed for dartabase_migration to do its magic
  *dartabase_migration/bin/projectsMapping.json       #maps project names to absolute project path
  *$yourProjectName/db/
  *$yourProjectName/db/config.json          #setting dartabase_migration information needed to connect IP/PORT/DBType
  *$yourProjectName/db/schema.json          #current dartabase_migration structure as JSON used by Dartabase tools
  *$yourProjectName/db/schemaVersion.json   #file 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 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  : dartabase_mapped_datatypes

        eg.
        "createTable": {
            "new_table_name_one": {
                "new_column_name": "DATATYPE"
            }
        }

    createColumn
    ------------
    "createColumn" key takes a json object as value

        keys    : existing_table_names
        values  : json object
                    keys    : non_existent_column_names
                    values  : dartabase_mapped_datatypes

        eg.
        "createColumn": {
            "existing_table_name_one": {
                "new_column_name": "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 name "user" with column "name" and datatype variable length of characters

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 to execute the dartabase_migration actions you specified inside the "DOWN" key.

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

{
    "BIGINT": "BIGINT",
    "BIGINT 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",
    "INTEGER": "INT",
    "INTEGER UNSIGNED": "INT UNSIGNED",
    "LONGBLOB": "LONGBLOB",
    "LONGTEXT": "LONGTEXT",
    "MEDIUMBLOB": "MEDIUMBLOB",
    "MEDIUMINT": "MEDIUMINT",
    "MEDIUMINT UNSIGNED": "MEDIUMINT UNSIGNED",
    "MEDIUMTEXT": "MEDIUMTEXT",
    "SMALLINT": "SMALLINT",
    "SMALLINT UNSIGNED": "SMALLINT UNSIGNED",
    "TEXT": "TEXT",
    "TIME": "TIME",
    "TIMESTAMP": "TIMESTAMP",
    "TINYBLOB": "TINYBLOB",
    "TINYINT": "TINYINT",
    "TINYINT UNSIGNED": "TINYINT UNSIGNED",
    "TINYTEXT": "TINYTEXT",
    "VARBINARY": "VARBINARY(255)",
    "VARCHAR": "VARCHAR(255)"
}

PGSQL

{
    "BIGINT": "bigint",
    "BIGINT 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",
    "INTEGER": "integer",
    "INTEGER UNSIGNED": "bigint",
    "LONGBLOB": "bytea",
    "LONGTEXT": "text",
    "MEDIUMBLOB": "bytea",
    "MEDIUMINT": "integer",
    "MEDIUMINT UNSIGNED": "integer",
    "MEDIUMTEXT": "text",
    "SMALLINT": "smallint",
    "SMALLINT UNSIGNED": "integer",
    "TEXT": "text",
    "TIME": "time",
    "TIMESTAMP": "timestamp",
    "TINYBLOB": "bytea",
    "TINYINT": "smallint",
    "TINYINT UNSIGNED": "smallint",
    "TINYTEXT": "text",
    "VARBINARY": "bytea",
    "VARCHAR": "varchar(255)"
}

COLUMN NAME

NEVER create a column named 'id'
an primary key column with name 'id' will be generates automatically for every table by dartabase migration
 

ENDING

Currently you need to manually stop the scripts from the editor or console after they are done.

Once it has stoped printing output and there have been no errors, it should be done.


Now you can add migration files for simple database manipulation

TODO

*fix async outputtext
*workarround for database problems with reserved words when switching DBAdapter from PG to MY.
    eg. table name 'user' will break in MySQL
    fix -> add '_' as prefix to column and table name
*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
*end scripts automatically 

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