Zend Db In ZF2

Zend Db In ZF2

Slides for a talk I gave at ZendCon 2012.

Corresponding code located at https://github.com/ralphschindler/Zend_Db-Examples


Ralph Schindler

October 23, 2012


  1. Zend\Db in ZF 2.0 1

  2. Who Am I? •Ralph Schindler (ralphschindler) Software Engineer on the

    Zend Framework team •At Zend for 4 years •Before that TippingPoint/3Com Programming PHP for 13+ years Live in New Orleans, LA. •Lived in Austin, Tx for 5 years 2 2
  3. ZF 2.0 •Next generation of Zend Framework •Embrace 5.3 (and

    5.4 in some places) •Embrace multiple programming paradigms AOP Event driven programming •More SOLID http://en.wikipedia.org/wiki/SOLID_(object-oriented_design) More interfaces, more possibility for extension Practice dependency injection •More Agile and open! No more CLA Code on github.com 3 3
  4. Zend\Db first pass... •Converted to namespaces •Converted to new Exception

    standards •Then, left alone while other things were developed on •Rewrite initial release in place of old Zend\Db during beta3 March 2012 4 4
  5. Zend\Db Requirements In Short •A more clear and concise API

    (single responsibility) •Open for extension (open/close principle) •Practice dependency injection •Favor composition over inheritance •Do not solve Model Domain problems 5 5
  6. What does that mean in practice •No statics anywhere 1

    Exception: •class Zend\Db\TableGateway\Feature\GlobalAdapterFeature •Lots of (simple) interfaces Construction Free / Dependency Free Interfaces •Zend\Db\Adapter can be treated like a collaborator (dependency) in other components Zend\Db\TableGateway Zend\Db\Sql Zend\Db\Metadata ... Zend\Db\ActiveRecord? 6 6
  7. What does that mean in practice, cont. •Very few Abstract

    classes ... Only in places where it is clear there is some shared implementation details •No final keyword on classes •No privates inside classes •All API are database centric, not model centric columns rows tables schemas 7 7
  8. Walking through Zend\Db •Under the Zend\Db Namespace: Adapter ResultSet Sql

    TableGateway RowGateway Metadata 8 8
  9. Insert->Header & Footer Zend\Db\Adapter\Adapter & Zend\Db\Adapter\ResultSet 9 9

  10. Zend\Db\Adapter •Zend\Db\Adapter is a namespace •Zend\Db\Adapter\Adapter is the “kernel” of

    Zend\Db •Zend\Db\Adapter\* are all the interfaces and implementation details of the Adapter 10 10
  11. https://github.com/zendframework/zf2/blob/master/library/Zend/Db/Adapter/Adapter.php 11

  12. Two Primary Parts of Zend\Db\Adapter •Driver •Platform 12 12

  13. Driver Responsibilities •Connecting to proper PHP extension •Reporting the capabilities

    of the extension •Coordinating 3 primary areas of interaction from driver object: Connections Statements Results 13 13
  14. Driver continued •Connection Interface wrapper for connection resource and/or functions

    14 14
  15. Driver continued •Statement interface wrapper for statement resource and/or functions

    15 15
  16. Driver continued •Result interface wrapper for result resource and/or function

    16 16
  17. Platform •Responsible for: Knowing how to quote in a vendor

    RDBMS specific way Knowing the "name" of the database in a code-neutral way 17 17
  18. Creating an Adapter •The really hard and explicit way ...

    18 18
  19. Creating An Adapter •The Easy and configuration driven way ...

    19 19
  20. Connection abstraction •first parameter of Adapter takes an array •Keys:

    driver, database, hostname, port, username, password, (pdodriver) any key you might find in php.net documentation 20 20
  21. Adapter Convenience •Convenience API 21 21

  22. Zend\Db\ResultSet •A collection of Rows •Model iteration in an Adapter/Driver

    neutral way •Present Rows as objects or arrays •There are A default concrete implementation ResultSet An abstract implementation for iterating common row sets An interface that enforces the Prototype pattern 22 22
  23. 23

  24. 24

  25. 25

  26. Insert->Header & Footer Zend\Db\Sql 26 26

  27. Zend\Db\Sql •Abstraction layer for creating DML (Data Manipulation Language in

    SQL) Select, Insert, Update, Delete •2 Modes Statement preparation SQL string generation 27 27
  28. Zend\Db\Sql cont. •Serializable, clone-able objects Contain no references to adapter

    or platform objects •Preform Adapter specific parameterization Does the driver use ? or does it use :name? •Abstraction for DDL (Data Definition Language in SQL) (not completed yet, planned for 2.1) 28 28
  29. Zend\Db\Sql\Insert, Update, Delete •Insert: 29 29

  30. Zend\Db\Sql\Insert, Update, Delete •Update: 30 30

  31. Zend\Db\Sql\Insert, Update, Delete •Delete 31 31

  32. Zend\Db\Sql\Select •Object for building queries •columns, joins, where, offset, limit

    •Ability to track identifiers and values in vendor and driver neutral way •Fluent API (LINQ style) 32 32
  33. Zend\Db\Sql\Select 33 about 30 or so of these reserved for

    later (demo time)... 33
  34. Zend\Db\Sql\Expression •Query/Statement agnostic value and identifier placeholders Uses “?” as

    common placeholder •Object to use for “pass through” of SQL fragments Much like Zend_Db_Expr in ZF1 34 34
  35. Zend\Db\Sql\Where & Predicates •Zend\Db\Sql\Where models SQL WHERE statements Is the

    first node of a tree •Zend\Db\Sql\Predicate are SQL predicates http://en.wikipedia.org/wiki/Where_(SQL) Truth values Combined by parenthesizes, AND and OR Predicate sets can be nested: •by API: $predicateSet->andPredicate($predicate); •or via Fluent: – $where->NEST->like(‘name’, ‘Ralph%’)->UNNEST; •example to follow in later slides 35 35
  36. This actually is the interface for where, as class Where

    extends Predicate {} ... 36
  37. Supported Predicates •Between •Expression SQL Fragment / Specialized functions, etc

    •In •IsNull •Like •Operator (>, <, =, <>, >=, <=) •Will explore more in Demo, if time permits https://github.com/zendframework/zf2/tree/master/library/Zend/Db/Sql/Predicate 37 37
  38. SQL Abstraction •Zend\Db\Sql\Sql is how you attain SQL abstraction according

    to the specific adapter / platform you are attempting to run against. They can be bound to a table Is used to take Select, Insert, Update, Delete objects and prepare or generate SQL for. 38 38
  39. 39



  42. Insert->Header & Footer Zend\Db\TableGateway Zend\Db\RowGateway 41 41

  43. Zend\Db\TableGateway •Table Data Gateway Pattern •http://martinfowler.com/eaaCatalog/tableDataGateway.html •“An object that acts

    as a Gateway to a database table. One instance handles all the rows in the table.” 42 42
  44. TableGateway Interface •TableGatewayInterface •TableGateway Implementations: AbstractTableGateway TableGateway 43 43

  45. TableGateway 44

  46. 45

  47. Zend\Db\RowGateway •Row Data Gateway •http://martinfowler.com/eaaCatalog/rowDataGateway.html •“An object that acts as

    a Gateway to a single record in a data source. There is one instance per row.” 46 46
  48. RowGateway Interface 47 47

  49. 48

  50. Insert->Header & Footer Zend\Db\Metadata 49 49

  51. Zend\Db\Metadata •Component capable of interrogating a database for schema information

    •Describe schema to consumers in a vendor neutral way •Cacheable and serializable 50 50
  52. Metadata Interface 51 51

  53. Insert->Header & Footer Learn By Example 52 52

  54. Examples •Zend\Db\Sql\Select Examples https://gist.github.com/3949548 •Working example repository: https://github.com/ralphschindler/Zend_Db-Examples/ Follow instructions

    there to setup working PDO sqlite file •essentially just: php setup/up.php •Another Framework-less project using Zend\Db https://github.com/ralphschindler/PatternsTutorialApp Explored Modeling with Zend\Db •Repository •Mapper •Entity •Data Mapper consuming Zend\Db\TableGateway 53 53
  55. Future •2.1 Db2 Adapter Oracle Adapter •2.1 or 2.2 DDL

    generation •2.2+ (If there is any demand) ActiveRecord using static inheritance 54 54
  56. Insert->Header & Footer Thanks! http://twitter.com/ralphschindler http://framework.zend.com/zf2 http://github.com/zendframework/ http://github.com/ralphschindler 55 55