Class: DB::Postgres::Connection

Inherits:
Async::Pool::Resource
  • Object
show all
Defined in:
lib/db/postgres/connection.rb

Overview

A high-level database connection that implements the standardized connection interface. This class provides a bridge between the underlying native PostgreSQL interface and the DB gem’s unified connection API.

Constant Summary collapse

FEATURES = 
DB::Features.new(
  alter_column_type: true,
  using_clause: true,
  conditional_operations: true,
  transactional_schema: true,
  batch_alter_table: true,
  concurrent_schema: true,
  serial_columns: true,
)

Instance Method Summary collapse

Constructor Details

#initialize(**options) ⇒ Connection

Initialize a new database connection.



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# File 'lib/db/postgres/connection.rb', line 17

def initialize(**options)
  @native = Native::Connection.connect(**options)
  
  super()
end

Instance Method Details

#append_identifier(value, buffer = String.new) ⇒ Object

Append an escaped identifier to the buffer.



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# File 'lib/db/postgres/connection.rb', line 76

def append_identifier(value, buffer = String.new)
  case value
  when Array
    first = true
    value.each do |part|
      buffer << "." unless first
      first = false
      
      buffer << @native.escape_identifier(part)
    end
  else
    buffer << @native.escape_identifier(value)
  end
  
  return buffer
end

#append_literal(value, buffer = String.new) ⇒ Object

Append a literal value to the buffer with appropriate formatting.



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# File 'lib/db/postgres/connection.rb', line 53

def append_literal(value, buffer = String.new)
  case value
  when Time, DateTime, Date
    append_string(value.iso8601, buffer)
  when Numeric
    buffer << value.to_s
  when TrueClass
    buffer << "TRUE"
  when FalseClass
    buffer << "FALSE"
  when nil
    buffer << "NULL"
  else
    append_string(value, buffer)
  end
  
  return buffer
end

#append_string(value, buffer = String.new) ⇒ Object

Append an escaped string value to the buffer.



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# File 'lib/db/postgres/connection.rb', line 43

def append_string(value, buffer = String.new)
  buffer << @native.escape_literal(value)
  
  return buffer
end

#close ⇒ Object

Close the database connection and release resources.



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# File 'lib/db/postgres/connection.rb', line 24

def close
  if @native
    @native&.close
    @native = nil
  end
  
  super
end

#features ⇒ Object

Database feature detection for migration and query building.



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# File 'lib/db/postgres/connection.rb', line 150

def features
  FEATURES
end

#key_column(name = "id", primary: true, null: false) ⇒ Object

Generate a key column definition for table creation.



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# File 'lib/db/postgres/connection.rb', line 98

def key_column(name = "id", primary: true, null: false)
  buffer = String.new
  
  append_identifier(name, buffer)
  
  if primary
    buffer << " BIGSERIAL"
  else
    buffer << " BIGINT"
  end
  
  if primary
    buffer << " PRIMARY KEY"
  elsif !null
    buffer << " NOT NULL"
  end
  
  return buffer
end

#next_result ⇒ Object

Get the next result set from a multi-result query.



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# File 'lib/db/postgres/connection.rb', line 134

def next_result
  @native.next_result
end

#send_query(statement) ⇒ Object

Send a query to the database server.



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# File 'lib/db/postgres/connection.rb', line 126

def send_query(statement)
  @native.discard_results
  
  @native.send_query(statement)
end

#status ⇒ Object

Get the current connection status.



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# File 'lib/db/postgres/connection.rb', line 120

def status
  @native.status
end

#types ⇒ Object

Get the type mapping for database types.



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# File 'lib/db/postgres/connection.rb', line 35

def types
  @native.types
end