My current pet project is a language-independent database migration library ( Wizardby in Google Code). This is largely inspired by ActiveRecord Migrations, but has a few subtleties. For example, it does some basic "type inference", so you do not need to specify the column type FK. He is also smart enough to generate “downgrade” scenarios, given only the “upgrade” sequence. Although the migration is written in a special DSL, this tool is primarily aimed at .NET projects. It is also database independent.
Here is a quick look at the syntax:
migration "Blog" revision => 1:
type-aliases:
type-alias N type => String, length => 200, nullable => false, default => ""
defaults:
default-primary-key ID type => Int32, nullable => false, identity => true
version 1:
add table Author:
FirstName type => N
LastName type => N
EmailAddress type => N, unique => true
Login type => N, unique => true
Password type => Binary, length => 64, nullable => true
add table Tag:
Name type => N
add table Blog:
Name type => N
Description type => String, nullable => false
add table BlogPost:
Title type => N
Slug type => N
BlogID references => Blog
AuthorID references => Author
add table BlogPostTagJunction primary-key => false:
BlogPostID references => BlogPost
TagID references => Tag
version 2:
add table BlogPostComment:
BlogPostID references => BlogPost
AuthorEmailAddress type => N
Content type => String, nullable => false
version 3:
add table Media:
TypeID type => Int32
Name type => N
MimeType type => N
Length type => Int32
BlogPostID nullable => true, references => BlogPost
BlogPostCommentID nullable => true, references => BlogPostComment
add table User:
Login type => String, length => 200, nullable => false
Password type => Binary, length => 64, nullable => false
index IX_Login columns => [ID, [Login, desc]], unique => true
version 4:
add table Forum:
Name type => String, length => 200, nullable => false
add column ModeratorUserID nullable => false, references => User
version 5:
remove index IX_Login table => User
version 6:
add index IX_Login table => User, columns => [ID, [Login, desc]], unique => true
version 7:
BlogAuthorJunction primary-key => false:
BlogID references => Blog
AuthorID references => Author
execute native-sql upgrade-resource => InsertSeedData, downgrade-resource => DeleteSeedData
I know other migration libraries, but hey, this is a pet project!
: ?