2. Xenogenetics for PL/SQLInfusing with Java Best Practices and Design Patterns

3. Blogger Presenter Author

4. Blogger Presenter

5. Xenogenetics for PL/SQLInfusing with Java Best Practices and Design Patterns

6. Zĕn'ə-jə-nĕt'ĭks for PL/SQLInfusing with Java Best Practices and Design Patterns

8. Developer

11. Design Patterns

12. solutionsforgenericproblems

14. “Someone has already solved your problems”

19. Design by Contract EncapsulationDecouplingAssertion

20. specification body Encapsulation

21. specification specification body body Decoupling

23. procedure proc (p_name in varchar2 ,p_sal in number ,p_hiredate in date )

24. Expectation regarding Valid Input procedure proc (p_name in varchar2 ,p_sal in number ,p_hiredate in date ) Agreed Contract

25. package dbc is AssertFail exception; c_AssertFail constant integer := -20999; pragmaexception_init (AssertFail, -20999); procedure assert (p_check in boolean ,p_msg in varchar2 := null ); end dbc;

26. procedure assert (p_check in boolean ,p_msg in varchar2 := null ) is begin if not nvl(p_check,false) -- fail on null input then raise_application_error ( c_AssertFail, 'Assertion Fail' ||': '||substr( nvl(p_msg, 'No Message') , 1, 200) ); end if; end assert;

27. Validate Input procedure proc (...) is begin dbc.assert (p_name is not null ,'The Name must be Filled' ); dbc.assert ((p_sal is not null and p_sal > 0) ,'The Salary must be greater than zero' ); dbc.assert (p_hiredate >= trunc (sysdate) ,'Hiredate must be in the Future' ); ... end proc; proc.sql

28. -- Description of this procedure -- -- %paramp_name Name of an Employee -- {*} Requirement Name must be provided -- -- %paramp_sal Salary of the Employee -- {*} Requirement Salary must be greater than zero -- -- %paramp_hiredateHiredate -- {*} Requirement Hiredate must be in the Future -- -- %raises DBC.AssertFail -- When a Parameter does not match the requirement

29. Allround Automations Plugin PLSQLDOC

31. (aka Inversion of Control) Advanced Decoupling Dependency Injection

34. PL/SQL Package PL/SQL Package PL/SQL Package PL/SQL Package PL/SQL Package HTTP Logger

35. PL/SQL Package PL/SQL Package PL/SQL Package PL/SQL Package PL/SQL Package HTTP Logger

36. Dependency Injection- Traditional Approach Central Package instead of hard-coding c_mailserverc_interest_ratec_vat_ratec_file_in_namec_log_level APP_CONSTANTS Package Package Package

37. True Injection Configuration Values property package value After Logon trigger mailserverinterest_ratevat_ratefile_in_namelog_levelurl_proxy emailertax_calctax_calcloggerloggerrss_reader amislin324.517.6app_log_xdebugamisvm2… setMailServer EMAILER setFileInName setLogLevel LOGGER setUrlProxy RSS_READER Dependency_Injector TAX_CALC setInterestRate setVatRate

38. From mere Value Injection to Interface Injection A component can specify it requires some simple configuration values to be injected directory name, email address, discount percentage It can also stipulate that it wants some ‘helpers’ complete functional components for example: a Logger, an Emailer, a Discount Calculation Service, an Order Validation , etc. The component will prescribe the interface the injected helper must have Reuse is promoted through injected dependencies

39. Interface Injection“If you give me a logger, I will write logging” Dependency_Injector LOGGER log_message( p_log_level in varchar2 , p_log_origin in varchar2 , p_log_message in varchar2 ); set_loglevel_threshold( p_log_level in varchar2);set_file_writer( p_file_writer in varchar2 HRM_SALARY_RULES /* Logger interface: p_log_level in varchar2 , p_log_origin in varchar2 , p_log_message in varchar2 */ set_logger (p_logger in varchar2)

40. Interface Injection“If you give me a logger, I will write logging” Dependency_Injector HRM_SALARY_RULES /* Logger interface: p_log_level in varchar2 , p_log_origin in varchar2 , p_log_message in varchar2 */ set_logger (p_logger in varchar2) NEW_LOGGER_IMPL Write_trace_message( p_log_level in varchar2 , p_log_origin in varchar2 , p_log_message in varchar2 );

41. Reusability

42. JSON Cross Session Communication

43. Why? process process process

44. Why? process process process

46. session session CentralCache session session

47. session session

48. session session

49. Q session session

50. ApplicationContext session session

51. namespace Name : Value Name : Value Name : Value Name : Value Name : Value Name : Value context1.sql

52. JavaScript Object Notation Lightweight data-interchange format

53. Name : Value

54. Name : Value, Name : Value, Name : Value

55. Name : Value, Name : Value, Name : Value Name : Value, Name : Value, Name : Value Name : Value, Name : Value, Name : Value , ,

56. {"ACCOUNTING" : { "EMPLOYEES" : [ {"ENAME" : "KING", "JOB" : "PRESIDENT", "SAL" : 5000 }, {"ENAME" : "MILLER", "JOB" : "CLERK", "SAL" : 1300 }] } }

57. <department name="ACCOUNTING"> <employees> <employee> <ename>KING</ename> <job>PRESIDENT</job> <sal>5000</sal> </employee> <employee> <ename>MILLER</ename> <job>CLERK</job> <sal>1300</sal> </employee> </employees> </department>

59. context2.sql

60. Caching session Cache package session session session

61. Caching session Cache package key value Alert Listener

62. Worker Session Worker Session Package (single session) client Worker Session dbms_job Worker Session Worker Session

63. Java Stored Procedure Unlocking the World

64. Challenges

65. Challenges Lack of Interaction Humans External Systems PL/SQL is limited

67. Q

73. From Xenophobia to Xenogenetics Established best practices in languages like Java can help improve use of PL/SQL Design by Contract, Encapsulation, Assertion, Reduced Impact of Changes Dependency Injection, Decoupling, Reuse Technical concepts in Java can have a meaningful counterpart in PL/SQL Data and Interaction across sessions

74. From Xenophobia to Xenogenetics De-facto standards – such as JSON – may make sense in a PL/SQL context And open source PL/SQL libraries may exist Through Java Stored Procedures, PL/SQL can leverage Java capabilities & libraries To interact through additional channels To calculate, process, generate, interpret

76. Lucas.Jellema@amis.nl Alex.Nuijten@amis.nl technology.amis.nl