Class: SqlPostgres::Savepoint

Inherits:
Object
  • Object
show all
Defined in:
lib/sqlpostgres/Savepoint.rb

Overview

This class handles a savepoint.

Example: ** example: savepoint

Transaction.new(connection) do

  insert = Insert.new('foo', connection)
  insert.insert('i', 1)
  insert.exec

  Savepoint.new('bar', connection) do |sp|
    insert = Insert.new('foo', connection)
    insert.insert('i', 2)
    sp.abort
  end

  insert = Insert.new('foo', connection)
  insert.insert('i', 3)
  insert.exec

end

p connection.query("select i from foo order by i") #[["1"], ["3"]]

**

Instance Method Summary collapse

Constructor Details

#initialize(name, connection = Connection.default) ⇒ Savepoint

Create an SQL savepoint, yield, and then commit the savepoint. If an exception occurs, the savepoint is aborted.

If no connection is given, then the default connection is used.



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# File 'lib/sqlpostgres/Savepoint.rb', line 35

def initialize(name, connection = Connection.default)
  @name = name
  @state = :open
  @finished = false
  @connection = connection
  @connection.exec("savepoint #{name}")
  begin
    result = yield(self)
    commit
    result
  rescue Exception
    abort
    raise
  end
end

Instance Method Details

#abort ⇒ Object

Abort this savepoint. This is done for you when an exception occurs within the block you passed to “new”. Call this when you want to abort a savepoint without throwing an exception.



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# File 'lib/sqlpostgres/Savepoint.rb', line 67

def abort
  unless @finished
    do_abort
  end
end

#commit ⇒ Object

Commit this savepoit. This is done for you unless an exception occurs within the block you passed to “new”. Call this when you want to commit the savepoint before raising an exception – in other words, when you want to keep your database changes even though an exception is about to occur.



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# File 'lib/sqlpostgres/Savepoint.rb', line 57

def commit
  unless @finished
    do_commit
  end
end