Zend Db In ZF2

Slides for a talk I gave at ZendCon 2012.

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

Transcript

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
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
40. LIMIT OFFSET EXAMPLE 40
41. LIMIT OFFSET EXAMPLE 40
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
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
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