2.9.0.txt

New Features

Compound SQL statement (i.e. UNION, EXCEPT, and INTERSECT) support is much improved. Chaining compound statement calls now longer wipes out previous compound statements calls of the same type. Also, the ordering of the compound statements is no longer fixed per adapter, it now reflects the order they were called on the object. For example, the following now work as expected:
```
ds1.union(ds2).union(ds3)
ds1.except(ds2).except(ds3)
ds1.intersect(ds2).intersect(ds3)
ds1.union(ds2).except(ds3)
ds1.except(ds2).intersect(ds3)
ds1.intersect(ds2).union(ds3)
```
Exception classes ValidationFailure and BeforeHookFailure were added so it is eaiser to catch a failed validation. These are both subclasses of Sequel::Error, so there shouldn’t be any backwards compatibility issues. Error messages are also improved, as the ValidationFailure message is a string containing all validation failures and the BeforeHookFailure message contains which hook type caused the failure (i.e. before_save, before_create, or before_validate).
The sequel command line tool now has a -L option to load all files in the given directory. This is mainly useful for loading a directory of model files. The files are loaded after the database connection is set up.
Methods to create and drop database functions, triggers, and procedural languages were added to the PostgreSQL adapter.

Other Improvements

Database#schema now raises an error if you pass a table that doesn’t exist. Before, some adapters would return an empty schema. The bigger problem with this is that it made table_exists? return the wrong value, since it looks at the Database’s schema. Generally, this bug would show up in the following code:
```
class Blah < Sequel::Model
end
Blah.table_exists? # True even if blahs is not a table
```
AlterTableGenerator#add_foreign_key now works for MySQL.
Error messages in model association methods that add/remove an associated object are now more descriptive.
Dataset#destroy for model datasets now works with databases that can’t handle nested queries. However, it now loads all model objects being destroyed before attempting to destroy any of them.
Dataset#count now works correctly for compound SQL statements (i.e. UNION, EXCEPT, and INTERSECT).
BigDecimal NaN and (+/-)Infinity values are now literalized correctly. Database support for this is hit or miss. Sqlite will work correctly, PostgreSQL raises an error if you try to store an infinite value in a numeric column (though it works for float columns), and MySQL converts all three to 0.
The SQLite adapter no longer loses primary key information when dropping columns.
The SQLite adapter now supports dropping indicies.
A bug in the MSSQL adapter’s literalization of LiteralStrings has been fixed.
The literalization of blobs on PostgreSQL (bytea columns) has been fixed.
Sequel now raises an error if you attempt to subclass Sequel::Model before setting up a database connection.

The native postgresql adapter has been changed to only log client messages of level WARNING by default. You can modify this via:

Sequel::Postgres.client_min_messages = nil # Use Server Default
Sequel::Postgres.client_min_messages = :notice # Use NOTICE level

Model#inspect now calls Model#inspect_values for easier overloading.

Backwards Compatibilty

The API to Model#save_failure (a private method) was changed to remove the second argument.
SQLite columns with type numeric, decimal, or money are now returned as BigDecimal values. Before, they were probably returned as strings.