# ANN: Sequel 3.8.0 Released **URL:** \ **Category:** Ruby\ **Created:** [January 4, 2010, 7:15pm UTC](https://www.ruby-forum.com/t/ann-sequel-3-8-0-released/181058 "2010-01-04T19:15:48Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![nerdmaster](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/c68b51/32.png) [@nerdmaster](https://www.ruby-forum.com/u/nerdmaster)\ **Post date:** [January 4, 2010, 7:15pm UTC](https://www.ruby-forum.com/t/ann-sequel-3-8-0-released/181058/1 "2010-01-04T19:15:48Z")
Sequel is a lightweight database access toolkit for Ruby. - Sequel provides thread safety, connection pooling and a concise DSL for constructing database queries and table schemas. - Sequel also includes a lightweight but comprehensive ORM layer for mapping records to Ruby objects and handling associated records. - Sequel supports advanced database features such as prepared statements, bound variables, stored procedures, master/slave configurations, and database sharding. - Sequel makes it easy to deal with multiple records without having to break your teeth on SQL. - Sequel currently has adapters for ADO, Amalgalite, DataObjects, DB2, DBI, Firebird, Informix, JDBC, MySQL, ODBC, OpenBase, Oracle, PostgreSQL and SQLite3. Sequel 3.8.0 has been released and should be available on the gem mirrors. ## New Features - Dataset#each\_server was added, allowing you to run the same query (most likely insert/update/delete) on all shards. This is useful if you have a sharded database but have lookup tables that should be identical on all shards. It works by yielding copies of the current dataset that are tied to each server/shard: - Database#each\_server was added, allowing you to run schema modification methods on all shards. It works by yielding a new Sequel::Database object for each shard, that will connect to only that shard: - You can now add and remove servers/shards from the connection pool while Sequel is running: - When you attempt to disconnect from a server that has connections currently in use, Sequel will now schedule those connections to be disconnected when they are returned to the pool. Previously, Sequel disconnected available connections, but ignored connections currently in use, so it wasn’t possible to guarantee complete disconnection from the server. Even with this new feature, you can only guarantee eventual disconnection, since disconnection of connections in use happens asynchronously. - Database#disconnect now accepts a :servers option specifying the server(s) from which to disconnect. This should be a symbol or array of symbols representing servers/shards. Only those specified will be disconnected: - A validates\_type validation was added to the validation\_helpers plugin. It allows you to check that a given column contains the correct type. I can be helpful if you are also using the serialization plugin to store serialized ruby objects, by making sure that the objects are of the correct type (e.g. Hash): - Sequel::SQL::Expression#== is now supported for all expressions: - When using the generic File type to create blob columns on MySQL, you can specify the specific database type by using the :size option (with :tiny, :medium, and :long values recognized): - The mysql adapter will now default to using mysqlplus, falling back to use mysql. mysqlplus is significantly better for threaded code because queries do not block the entire interpreter. - The JDBC adapter is now able to detect certain types of disconnect errors. - ConnectionPool.servers and Database.servers were added, which return an array of symbols specifying the servers/shards in use. ## Other Improvements - The single-threaded connection pool now raises DatabaseConnectionErrors if unable to connect, so it now operates more similarly to the default connection pool. - The single-threaded connection pool now operates more similar to the default connection pool when given a nonexistent server. - PGErrors are now correctly converted to DatabaseErrors in the postgres adapter when preparing statements or executing prepared statements. - DatabaseDisconnectErrors are now raised correctly in the postgres adapter if the connection status is not OK after a query raises an error. - In the mysql adapter, multiple statements in a single query should now be handled correctly in the all cases, not just when using Dataset#each. So you can now submit multiple queries in a single string to Database#run. - Model object creation on Microsoft SQL Server 2000 once again works correctly. Previously, an optimization was used that was only supported on 2005+. - Backslashes are no longer doubled inside string literals when connecting to Microsoft SQL Server. - The ORDER clause now correctly comes after the HAVING clause on Microsoft SQL Server. - Sequel now checks that there is an active transaction before rolling back transactions on Microsoft SQL Server, since there are cases where Microsoft SQL Server will roll back transactions implicitly. - Blobs are now handled correctly when connecting to H2. - 64-bit integers are now handled correctly in JDBC prepared statements. - In the boolean\_readers plugin, correctly handle columns not in the db\_schema, and don’t raise an error if the model’s columns can’t be determined. - In the identity\_map plugin, remove instances from the cache if they are deleted or destroyed. ## Backwards Compatibility - Dataset::FROM\_SELF\_KEEP\_OPTS was merged into Dataset::NON\_SQL\_OPTIONS. While used in different places, they were used for the same purpose, and entries missing from one should have been included in the other. - The connection pool internals changed substantially. Now, ConnectionPool #allocated and #available\_connections will return nil instead of an array or hash if they are called with a nonexistent server. These are generally only used internally, though they are part of the public API. #created\_count and #size still return the size of the :default server when called with a nonexistent server, though. - The meta\_eval and metaclass private methods were removed from Sequel::MetaProgramming (only the meta\_def public method remains). If you want these methods, use the metaid gem. - The irregular ox-\>oxen pluralization rule was removed from the default inflections, as it screws up the more common box-\>boxes. Thanks, Jeremy - {Website}[[http://sequel.rubyforge.org](http://sequel.rubyforge.org)] - {Source code}[[GitHub - jeremyevans/sequel: Sequel: The Database Toolkit for Ruby](http://github.com/jeremyevans/sequel)] - {Bug tracking}[[Google Code Archive - Long-term storage for Google Code Project Hosting.](http://code.google.com/p/ruby-sequel/issues/list)] - {Google group}[[http://groups.google.com/group/sequel-talk](http://groups.google.com/group/sequel-talk)] - {RDoc}[[http://sequel.rubyforge.org/rdoc](http://sequel.rubyforge.org/rdoc)]