Class: PartitionGardener::PgConnection

Inherits:
Object
  • Object
show all
Defined in:
lib/partition_gardener/pg_connection.rb

Defined Under Namespace

Classes: Result

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(raw_connection) ⇒ PgConnection

Returns a new instance of PgConnection.



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# File 'lib/partition_gardener/pg_connection.rb', line 37

def initialize(raw_connection)
  @raw_connection = raw_connection
end

Class Method Details

.connect(database_url) ⇒ Object 



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# File 'lib/partition_gardener/pg_connection.rb', line 33

def self.connect(database_url)
  new(PG.connect(database_url))
end

Instance Method Details

#execute(sql) ⇒ Object 



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# File 'lib/partition_gardener/pg_connection.rb', line 66

def execute(sql)
  Result.new(@raw_connection.exec(sql))
end

#quote(value) ⇒ Object 



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# File 'lib/partition_gardener/pg_connection.rb', line 41

def quote(value)
  case value
  when nil
    "NULL"
  when true
    "TRUE"
  when false
    "FALSE"
  when Numeric
    value.to_s
  when Date, Time
    "'#{@raw_connection.escape_string(value.iso8601)}'"
  else
    "'#{@raw_connection.escape_string(value.to_s)}'"
  end
end

#quote_column_name(name) ⇒ Object 



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# File 'lib/partition_gardener/pg_connection.rb', line 62

def quote_column_name(name)
  quote_table_name(name)
end

#quote_table_name(name) ⇒ Object 



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# File 'lib/partition_gardener/pg_connection.rb', line 58

def quote_table_name(name)
  @raw_connection.quote_ident(name.to_s)
end

#table_exists?(table_name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/partition_gardener/pg_connection.rb', line 79

def table_exists?(table_name)
  sql = <<~SQL
    SELECT EXISTS (
      SELECT 1
      FROM pg_catalog.pg_class AS relation
      JOIN pg_catalog.pg_namespace AS namespace ON namespace.oid = relation.relnamespace
      WHERE namespace.nspname = ANY (current_schemas(false))
        AND relation.relname = $1
        AND relation.relkind IN ('r', 'p')
    ) AS exists
  SQL
  result = @raw_connection.exec_params(sql, [table_name.to_s])
  result.getvalue(0, 0) == "t"
end

#transaction ⇒ Object 



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# File 'lib/partition_gardener/pg_connection.rb', line 70

def transaction
  @raw_connection.exec("BEGIN")
  yield
  @raw_connection.exec("COMMIT")
rescue
  @raw_connection.exec("ROLLBACK")
  raise
end