module Sequel::Plugins::PreparedStatements

  1. lib/sequel/plugins/prepared_statements.rb

The prepared_statements plugin modifies the model to use prepared statements for instance level saves (inserts and updates). It also will use prepared statements for deletes, refreshes, and class level lookups by primary key, if it thinks that using a prepared statement will be faster in such cases.

Note that this plugin is unsafe in some circumstances, as it can allow up to 2^N prepared statements to be created for each type of insert and update query, where N is the number of colums in the table. It is recommended that you use the prepared_statements_safe plugin in addition to this plugin to reduce the number of prepared statements that can be created, unless you tightly control how your model instances are saved.

Usage:

# Make all model subclasses use prepared statements  (called before loading subclasses)
Sequel::Model.plugin :prepared_statements

# Make the Album class use prepared statements
Album.plugin :prepared_statements

Methods

Public Class

  1. apply

Constants

MUTEX = Mutex.new  

Synchronize access to the integer sequence so that no two calls get the same integer.

NEXT = lambda{MUTEX.synchronize{i += 1}}  

This plugin names prepared statements uniquely using an integer sequence, this lambda returns the next integer to use.

Public Class methods

apply (model)

Setup the datastructure used to hold the prepared statements in the model.

[show source]
# File lib/sequel/plugins/prepared_statements.rb, line 33
def self.apply(model)
  model.instance_variable_set(:@prepared_statements, {:insert=>{}, :insert_select=>{}, :update=>{}, :lookup_sql=>{}, :fixed=>{}}.freeze)
end