i.e. Oracle database does not support these isolation levels.
`:read_uncommitted` `:repeatable_read`
This commit also works with other databases which do not support
these isolation levels.
This commit allows a user to do something like:
before_validation :do_stuff, :on => [ :create, :update ]
after_validation :do_more, :on => [ :create, :update ]
This reverts commit 761bc751d31c22e2c2fdae2b4cdd435b68b6d783.
This commit wasn't fixing any issue just using the same table for
different models with different primary keys.
If your database supports setting the isolation level for a transaction,
you can set it like so:
Post.transaction(isolation: :serializable) do
# ...
end
Valid isolation levels are:
* `:read_uncommitted`
* `:read_committed`
* `:repeatable_read`
* `:serializable`
You should consult the documentation for your database to understand the
semantics of these different levels:
* http://www.postgresql.org/docs/9.1/static/transaction-iso.html
* https://dev.mysql.com/doc/refman/5.0/en/set-transaction.html
An `ActiveRecord::TransactionIsolationError` will be raised if:
* The adapter does not support setting the isolation level
* You are joining an existing open transaction
* You are creating a nested (savepoint) transaction
The mysql, mysql2 and postgresql adapters support setting the
transaction isolation level. However, support is disabled for mysql
versions below 5, because they are affected by a bug
(http://bugs.mysql.com/bug.php?id=39170) which means the isolation level
gets persisted outside the transaction.
If assigning to a has_many :through collection against an unsaved
object using the collection=[<array_of_items>] syntax, the join models
were not properly created, previously.
The COUNT clause of a finder_sql relationship is being rewritten from
COUNT(*) to COUNT(table_name.*). This does not appear to be valid syntax
in MySQL:
```
mysql> SELECT COUNT( table_name.* ) FROM `table_name`;
ERROR 1064 (42000): You have an error in your SQL syntax; check the
manual that corresponds to your MySQL server version for the right
syntax to use near '* ) FROM `table_name`' at line 1
```
This fixes the bug, as well as adding tests so we don't re-introduce
it in the future.
Fixes#3956.
This method was first seen in 045713ee240fff815edb5962b25d668512649478,
and subsequently reimplemented in
fb2325e35855d62abd2c76ce03feaa3ca7992e4f.
According to @jeremy, this is okay to remove. He thinks it was added
because at the time we didn't have much transaction state to keep track
of, and he viewed it as a hack for us to track it internally, thinking
it was better to ask the connection for the transaction state.
Over the years we have added more and more state to track, a lot of
which is impossible to ask the connection for. So it seems that this is
just a relic of the passed and we will just track the state internally
only.
Having column related schema dumper code in the AbstractAdapter. The
code remains the same, but by placing it in the AbstractAdapter, we can
then overwrite it with Adapter specific methods that will help with
Adapter specific data types.
The goal of moving this code here is to create a new migration key for
PostgreSQL's array type. Since any datatype can be an array, the goal is
to have ':array => true' as a migration option, turning the datatype
into an array. I've implemented this in postgres_ext, the syntax is
shown here: https://github.com/dockyard/postgres_ext#arrays
Adds array migration support
Adds array_test.rb outlining the test cases for array data type
Adds pg_array_parser to Gemfile for testing
Adds pg_array_parser to postgresql_adapter (unused in this commit)
Adds schema dump support for arrays
Adds postgres array type casting support
Updates changelog, adds note for inet and cidr support, which I forgot to add before
Removing debugger, Adds pg_array_parser to JRuby platform
Removes pg_array_parser requirement, creates ArrayParser module used by
PostgreSQLAdapter
- added tests to confirm establish_connection uses DATABASE_URL and
Rails.env correctly even when no arguments are passed in.
- updated rake db tasks to support DATABASE_URL, and added tests to
confirm correct behavior for these rake tasks. (Removed
establish_connection call from some tasks since in those cases
the :environment task already made sure the function would be called)
- updated Resolver so that when it resolves the database url, it
removes hash values with empty strings from the config spec (e.g.
to support connection to postgresql when no username is specified).
Allows you to specify the model association key in a belongs_to
relationship instead of the foreign key.
The following queries are now equivalent:
Post.where(:author_id => Author.first)
Post.where(:author => Author.first)
PriceEstimate.where(:estimate_of_type => 'Treasure', :estimate_of_id => treasure)
PriceEstimate.where(:estimate_of => treasure)
As a result of different commits, ConnectionPool had become
of two minds about exceptions, sometimes using PoolFullError
and sometimes using ConnectionTimeoutError. In fact, it was
using ConnectionTimeoutError internally, but then recueing
and re-raising as a PoolFullError.
There's no reason for this bifurcation, standardize on
ConnectionTimeoutError, which is the rails2 name and still
accurately describes semantics at this point.
History
In Rails2, ConnectionPool raises a ConnectionTimeoutError if
it can't get a connection within timeout.
Originally in master/rails3, @tenderlove had planned on removing
wait/blocking in connectionpool entirely, at that point he changed
exception to PoolFullError.
But then later wait/blocking came back, but exception remained
PoolFullError.
Then in 02b233556377 pmahoney introduced fair waiting logic, and
brought back ConnectionTimeoutError, introducing the weird bifurcation.
ConnectionTimeoutError accurately describes semantics as of this
point, and is backwards compat with rails2, there's no reason
for PoolFullError to be introduced, and no reason for two
different exception types to be used internally, no reason
to rescue one and re-raise as another. Unify!
When calling a query method on an attribute that was not selected by
an ActiveRecord query, an ActiveModel::MissingAttributeError is not
raised. Instead, a nil value is returned, which will return false once
cast to boolean.
This is undesirable, as we should not give the impression that we know
the attribute's boolean value when we haven't loaded the attribute's
(possibly) non-boolean value from the database.
This issue is present on versions going back as far as 2.3, at least.
