public void Automatically_migrate_to_new_Schema()
{
var repository = new BlogRepository(redisClient);
//Populate the datastore with the old schema from the 'BlogPostBestPractice'
BlogPostBestPractice.InsertTestData(repository);
//Create a typed-client based on the new schema
using (var redisBlogPosts = redisClient.GetTypedClient <New.BlogPost>())
{
//Automatically retrieve blog posts
IList <New.BlogPost> allBlogPosts = redisBlogPosts.GetAll();
//Print out the data in the list of 'New.BlogPost' populated from old 'BlogPost' type
//Note: renamed fields are lost
Debug.WriteLine(allBlogPosts.Dump());
/*Output:
* [
* {
* Id: 3,
* BlogId: 2,
* PostType: None,
* Title: Redis,
* Labels: [],
* Tags:
* [
* Redis,
* NoSQL,
* Scalability,
* Performance
* ],
* Comments:
* [
* {
* Content: First Comment!,
* CreatedDate: 2010-04-28T21:42:03.9484725Z
* }
* ]
* },
* {
* Id: 4,
* BlogId: 2,
* PostType: None,
* Title: Couch Db,
* Labels: [],
* Tags:
* [
* CouchDb,
* NoSQL,
* JSON
* ],
* Comments:
* [
* {
* Content: First Comment!,
* CreatedDate: 2010-04-28T21:42:03.9484725Z
* }
* ]
* },
* {
* Id: 1,
* BlogId: 1,
* PostType: None,
* Title: RavenDB,
* Labels: [],
* Tags:
* [
* Raven,
* NoSQL,
* JSON,
* .NET
* ],
* Comments:
* [
* {
* Content: First Comment!,
* CreatedDate: 2010-04-28T21:42:03.9004697Z
* },
* {
* Content: Second Comment!,
* CreatedDate: 2010-04-28T21:42:03.9004697Z
* }
* ]
* },
* {
* Id: 2,
* BlogId: 1,
* PostType: None,
* Title: Cassandra,
* Labels: [],
* Tags:
* [
* Cassandra,
* NoSQL,
* Scalability,
* Hashing
* ],
* Comments:
* [
* {
* Content: First Comment!,
* CreatedDate: 2010-04-28T21:42:03.9004697Z
* }
* ]
* }
* ]
*
*/
}
}
public void Manually_migrate_to_new_Schema_using_a_custom_tranlation()
{
var repository = new BlogRepository(redisClient);
//Populate the datastore with the old schema from the 'BlogPostBestPractice'
BlogPostBestPractice.InsertTestData(repository);
//Create a typed-client based on the new schema
using (var redisBlogPosts = redisClient.GetTypedClient <BlogPost>())
using (var redisNewBlogPosts = redisClient.GetTypedClient <New.BlogPost>())
{
//Automatically retrieve blog posts
IList <BlogPost> oldBlogPosts = redisBlogPosts.GetAll();
//Write a custom translation layer to migrate to the new schema
var migratedBlogPosts = oldBlogPosts.ConvertAll(old => new New.BlogPost
{
Id = old.Id,
BlogId = old.BlogId,
Title = old.Title,
Content = old.Content,
Labels = old.Categories, //populate with data from renamed field
PostType = New.BlogPostType.Article, //select non-default enum value
Tags = new HashSet <string>(old.Tags),
Comments = old.Comments.ConvertAll(x => new Dictionary <string, string>
{
{ "Content", x.Content }, { "CreatedDate", x.CreatedDate.ToString() },
}),
NoOfComments = old.Comments.Count, //populate using logic from old data
});
//Persist the new migrated blogposts
redisNewBlogPosts.StoreAll(migratedBlogPosts);
//Read out the newly stored blogposts
var refreshedNewBlogPosts = redisNewBlogPosts.GetAll();
//Note: data renamed fields are successfully migrated to the new schema
Debug.WriteLine(refreshedNewBlogPosts.Dump());
/*
* [
* {
* Id: 3,
* BlogId: 2,
* PostType: Article,
* Title: Redis,
* Labels:
* [
* NoSQL,
* Cache
* ],
* Tags:
* [
* Redis,
* NoSQL,
* Scalability,
* Performance
* ],
* Comments:
* [
* {
* Content: First Comment!,
* CreatedDate: 28/04/2010 22:58:35
* }
* ],
* NoOfComments: 1
* },
* {
* Id: 4,
* BlogId: 2,
* PostType: Article,
* Title: Couch Db,
* Labels:
* [
* NoSQL,
* DocumentDB
* ],
* Tags:
* [
* CouchDb,
* NoSQL,
* JSON
* ],
* Comments:
* [
* {
* Content: First Comment!,
* CreatedDate: 28/04/2010 22:58:35
* }
* ],
* NoOfComments: 1
* },
* {
* Id: 1,
* BlogId: 1,
* PostType: Article,
* Title: RavenDB,
* Labels:
* [
* NoSQL,
* DocumentDB
* ],
* Tags:
* [
* Raven,
* NoSQL,
* JSON,
* .NET
* ],
* Comments:
* [
* {
* Content: First Comment!,
* CreatedDate: 28/04/2010 22:58:35
* },
* {
* Content: Second Comment!,
* CreatedDate: 28/04/2010 22:58:35
* }
* ],
* NoOfComments: 2
* },
* {
* Id: 2,
* BlogId: 1,
* PostType: Article,
* Title: Cassandra,
* Labels:
* [
* NoSQL,
* Cluster
* ],
* Tags:
* [
* Cassandra,
* NoSQL,
* Scalability,
* Hashing
* ],
* Comments:
* [
* {
* Content: First Comment!,
* CreatedDate: 28/04/2010 22:58:35
* }
* ],
* NoOfComments: 1
* }
* ]
*
*/
}
}
