Ruby Cookbook

Recipe 13.1. Serializing Data with YAML Problem You want to serialize a data structure and use it later. You may want to send the data structure to a file, then load it into a program written in a different programming language. Solut...

Recipe 13.2. Serializing Data with Marshal Problem You want to serialize a data structure to disk faster than YAML can do it. You don't care about the readability of the serialized data structure, or portability to other programming langua...

Recipe 13.3. Persisting Objects with Madeleine Problem You want to store objects in RAM and persist them between independent executions of the program. This will let your program recall its state indefinitely and access it very quickly. ...

Recipe 13.4. Indexing Unstructured Text with SimpleSearch Problem You want to index a number of texts and do quick keyword searches on them. Solution Use the SimpleSearch library, available in the SimpleSearch gem. Here's how to ...

Recipe 13.5. Indexing Structured Text with Ferret Problem You want to perform searches on structured text. For instance, you might want to search just the headline of a news story, or just the body. Discussion The Ferret library can ...

Recipe 13.6. Using Berkeley DB Databases Problem You want a simple, fast database that doesn't need a server to run. Solution Ruby's standard dbm library lets you store a database in a set of standalone binary files. It's not a SQL d...

Recipe 13.7. Controlling MySQL on Unix Problem The standard Ruby database interfaces assume you're connecting to a preexisting database, and that you already have access to this database. You want to create and administer MySQL database...

Recipe 13.8. Finding the Number of Rows Returned by a Query Problem Writing a DBI program, you want an efficient way to see how many rows were returned by a query. Solution A do command returns the number of rows affected by the comm...

Recipe 13.9. Talking Directly to a MySQL Database Problem You want to send SQL queries and commands directly to a MySQL database. Solution Do you really need to do this? Almost all the time, it's better to use the generic DBI library...

Recipe 13.10. Talking Directly to a PostgreSQL Database Problem You want to send SQL queries and commands directly to a PostgreSQL database. Solution As with the MySQL recipe preceding this one, ask: do you really need to do this?...

Recipe 13.11. Using Object Relational Mapping with ActiveRecord Problem You want to store data in a database without having to use SQL to access it. Solution Use the ActiveRecord library, available as the activerecord gem. It automat...

Recipe 13.12. Using Object Relational Mapping with Og Credit: Mauro Cicio Problem You want to store data in a database, without having to use SQL to create or access the database. Solution Use the Og (ObjectGraph) library, available...

Recipe 13.13. Building Queries Programmatically Problem You have to write fragments of SQL to pass parameters into an ActiveRecord query. You'd like to dispense with SQL altogether, and represent the query paramaters as a Ruby data structu...

Recipe 13.14. Validating Data with ActiveRecord Problem You want to prevent bad data from getting into your ActiveRecord data objects, whether the source of the data is clueless users or buggy code. Solution The simplest way is to us...

Recipe 13.15. Preventing SQL Injection Attacks Problem You want to harden your code against SQL injection attacks, whether in DBI or ActiveRecord code. Solution With both ActiveRecord and DBI applications, you should create your SQL ...

Recipe 13.16. Using Transactions in ActiveRecord Problem You want to perform database operations as a group: if one of the operations fails, it should be as though none of them had ever happened. Solution Include active_record/ tra...

Recipe 13.17. Adding Hooks to Table Events Problem You want to run some code whenever a database row is added, updated, or deleted. For instance, you might want to send out email whenever a new blog post is created. Solution For Og, ...