#pg_runner

About pg_runner

Providing connection pool and easy query tools for postgresql

Required Gems & Linux library

• libpq-dev

libpq is a set of library functions that allow client programs to pass queries to the PostgreSQL backend server and to receive the results of these queries.

• official site
  • http://www.postgresql.org/docs/9.1/static/libpq.html
• Installation

# at Ubuntu
$$ apt-get install libpq-dev

• postgres(pg)

A ruby gem for postgresql

• official site
  • https://bitbucket.org/ged/ruby-pg/wiki/Home
  • https://github.com/ged/ruby-pg
• Installation

$$ gem install pg

Class

• PG::BasicConnectionPool

A database connection pool for postgresql. Default pool size is 5.

• PG::SingleConnectionPool

A database connection pool supporting only one connection for postgresql. This is a fake connection pool for the transaction function of SqlRunner

• PG::SqlRunner

A simple sql executer class

Example Code

Create BasicConnectionPool and SqlRunner

connection_pool = PG::BasicConnectionPool.new( dbhost, port, dbname, username, password, pool_sise(optional) )
runner = PG::SqlRunner.new( connection_pool )

Simple query

# query
rs = runner.query( "select 1" )
rs.each do | row |
  # do something
end

# query with block
rs = runner.query( "select * from blabla where $1 = 1" ) do | result |
  # do something
end


# query with params
rs = runner.query(  "select * from blabla where $1 = 1" , [1] )

# query with params & block
rs = runner.query( "select * from blabla where $1 = 1" , [1] ) do | result |
  # do something
end

Transaction

runner.transaction do | runner |
    # do some transaction works with runner
    # raise Exception if you want rollback
end

Work through PG::Connection

# work with PG::Connection
runner.connect do | conn | do
  # bla bla~
end