Class: SQLRunner::Adapters::PostgreSQL

Inherits:
Object
  • Object
show all
Defined in:
lib/sql_runner/adapters/postgresql.rb

Constant Summary collapse

InvalidPreparedStatement = 
Class.new(StandardError)

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(connection_string) ⇒ PostgreSQL

Returns a new instance of PostgreSQL.



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# File 'lib/sql_runner/adapters/postgresql.rb', line 12

def initialize(connection_string)
  @connection_string = connection_string
  connect
end

Class Method Details

.load ⇒ Object 



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# File 'lib/sql_runner/adapters/postgresql.rb', line 6

def self.load
  require "pg"
rescue LoadError
  fail MissingDependency, "make sure the pg gem is available"
end

Instance Method Details

#active? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/sql_runner/adapters/postgresql.rb', line 52

def active?
  @connection && @connection.status == PG::Connection::CONNECTION_OK
rescue PGError
  false
end

#connect(started = Process.clock_gettime(Process::CLOCK_MONOTONIC)) ⇒ Object 



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# File 'lib/sql_runner/adapters/postgresql.rb', line 17

def connect(started = Process.clock_gettime(Process::CLOCK_MONOTONIC))
  @connection = PG.connect(@connection_string)
rescue PG::ConnectionBad
  ended = Process.clock_gettime(Process::CLOCK_MONOTONIC)

  if ended - started < SQLRunner.timeout
    sleep 0.1
    connect(started)
  else
    raise
  end
end

#connection ⇒ Object 



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# File 'lib/sql_runner/adapters/postgresql.rb', line 39

def connection
  @connection
end

#disconnect ⇒ Object 



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# File 'lib/sql_runner/adapters/postgresql.rb', line 30

def disconnect
  @connection && @connection.close && (@connection = nil)
end

#execute(query, **bind_vars) ⇒ Object 



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# File 'lib/sql_runner/adapters/postgresql.rb', line 43

def execute(query, **bind_vars)
  query, bindings = parse(query)
  args = extract_args(query, bindings, bind_vars)
  @connection.exec_params(query, args)
rescue PG::ConnectionBad
  reconnect
  execute(query, **bind_vars)
end

#inspect ⇒ Object 



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# File 'lib/sql_runner/adapters/postgresql.rb', line 62

def inspect
  to_s
end

#parse(query) ⇒ Object 



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# File 'lib/sql_runner/adapters/postgresql.rb', line 66

def parse(query)
  bindings = {}
  count = 0

  parsed_query = query.gsub(/(:?):([a-zA-Z]\w*)/) do |match|
    next match if $1 == ":" # skip type casting

    name = match[1..-1]
    sym_name = name.to_sym

    if (!index = bindings[sym_name])
      index = (count += 1)
      bindings[sym_name] = index
    end

    "$#{index}"
  end

  [parsed_query, bindings]
end

#reconnect ⇒ Object 



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# File 'lib/sql_runner/adapters/postgresql.rb', line 34

def reconnect
  disconnect
  connect
end

#to_s ⇒ Object 



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# File 'lib/sql_runner/adapters/postgresql.rb', line 58

def to_s
  %[#<#{self.class.name} #{"0x00%x" % (object_id << 1)}>]
end