a testing framework for microsoft sql-server

1A testing framework for Microsoft SQL-Server, Jorge Almeida, Dezembro 2006

A testing framework for Microsoft SQL-Server

Jorge Almeida

2A testing framework for Microsoft SQL-Server, Jorge Almeida, Dezembro 2006

Summary

• Database Testing in an RDBMS Unit test framework for databases

• Database manual testing• Database automatized tests • Database testing tools• TSQLUnit framework• How to write T-SQL unit tests• Conclusions• References

3A testing framework for Microsoft SQL-Server, Jorge Almeida, Dezembro 2006

Database Testing in an RDBMS

4A testing framework for Microsoft SQL-Server, Jorge Almeida, Dezembro 2006

Database Testing

• Categories of database tests– Interface tests (validate what is going into, out of, and mapped)– Internal database tests (validate the internal structure, behavior

and contents)

• Internal database tests should validate:– Database methods (e.g. stored procedures, functions, and

triggers)– Existence of database schema elements (tables, procedures, ...)– View definitions– Referential integrity rules– Default values for a column– Data invariants for a single column– Data invariants involving several columns

5A testing framework for Microsoft SQL-Server, Jorge Almeida, Dezembro 2006

Database Manual Testing

• Combination of PRINT statements and ad-hoc tests with the SQL Query Analyzer

• Trace/debug tools like SQL Profiler• Human judgment is required to analyze

the results

• The tests can not easily be repeated again

6A testing framework for Microsoft SQL-Server, Jorge Almeida, Dezembro 2006

Database Automatized Tests

• Can be repeated over and over again

• Improve the quality of the code (refactoring)

• Serve the purpose of documentation

• May improve the design

7A testing framework for Microsoft SQL-Server, Jorge Almeida, Dezembro 2006

Database testing tools

• Category of database testing (interface and internal)

• Support the language of developing• Help putting the database into a known

state

8A testing framework for Microsoft SQL-Server, Jorge Almeida, Dezembro 2006

Some database testing tools

•Data Factory•Datatect•DTM Data Generator

•Turbo Data

Developers need test data against which to validate their systems. Test data generators can be particularly useful when need large amounts of data, for stress and load testing

Test data generator

•Empirix•Mercury Interactive•RadView

•Rational Suite Test Studio•Web Performance

Tools simulate high usage loads on database, enabling to determine whether the system’s architecture will stand up to true production needs

Testing tools for load testing

•DBUnit•NDbUnit•OUnit for Oracle (being replaced soon by Qute)•SQLUnit•TSQLUnit•Visual Studio Team Edition for Database Professionals

Tools which enable regression testUnit testing tools

ExamplesDescriptionCategory

9A testing framework for Microsoft SQL-Server, Jorge Almeida, Dezembro 2006

TSQLUnit

• A testing framework for Microsoft SQL-Server• It follows the tradition of the "xUnit" framework • TSQLUnit is open source

• Developed by Henrik Ekelund• Unit testing for stored procedures, functions,

triggers and views• Available from

http://sourceforge.net/projects/tsqlunit • Version 0.9 (December 15, 2002)

10A testing framework for Microsoft SQL-Server, Jorge Almeida, Dezembro 2006

TSQLUnit Install

• Download file from http://tsqlunit.sourceforge.net/tsqlunit_download.htm

• Unzip the file

• Connect to database as dbo using the SQL Query Analyzer, execute the tsqlunit.sql file

11A testing framework for Microsoft SQL-Server, Jorge Almeida, Dezembro 2006

Basic principles of database testing

• Database with good test data

• Shouldn’t developing against a production database

• Test one feature only per test procedure

• Be careful of how T-SQL comparison operators work

• When it is difficult to write tests change the design or refactor the system

12A testing framework for Microsoft SQL-Server, Jorge Almeida, Dezembro 2006

How to write T-SQL unit tests

• Create a stored procedure with a name that starts with ut and underscore (e.g. ut_testSomething)

• Code a test, then call tsu_failure if test fails

• Execute tsu_runTests

13A testing framework for Microsoft SQL-Server, Jorge Almeida, Dezembro 2006

Test example (1)

CREATE PROCEDURE ut_CapitalizeOneSentence ASBEGIN

DECLARE @outStr VARCHAR(500)EXECUTE capitalize ‘a string’, @outStr OUTPUTIF ASCII(LEFT(@outStr,1)) <> ASCII(‘A’) OR @outStr IS NULL

EXECUTE tsu_failure ‘Capitalize should make the first character uppercase’END

CREATE PROCEDURE capitalize

@inStr VARCHAR(500)=NULL,

@outStr VARCHAR(500)=NULL OUTPUT AS

BEGIN

SET @outStr=NULL

IF @inStr IS NOT NULL

SET @outStr=UPPER(LEFT(@inStr,1))+RIGHT(@inStr,LEN(@inStr)-1)

END

14A testing framework for Microsoft SQL-Server, Jorge Almeida, Dezembro 2006

Test example (2)

CREATE PROCEDURE ut_CapitalizeNullSentence ASBEGIN

DECLARE @outStr VARCHAR(500)EXECUTE capitalize NULL, @outStr OUTPUTIF @outStr IS NOT NULL

EXECUTE tsu_failure ‘Capitalize should not return any value’END

CREATE PROCEDURE capitalize

@inStr VARCHAR(500)=NULL,

@outStr VARCHAR(500)=NULL OUTPUT AS

BEGIN

SET @outStr=NULL

IF @inStr IS NOT NULL

SET @outStr=UPPER(LEFT(@inStr,1))+RIGHT(@inStr,LEN(@inStr)-1)

END

15A testing framework for Microsoft SQL-Server, Jorge Almeida, Dezembro 2006

Test example (3)

CREATE PROCEDURE ut_CapitalizeEmptySentence ASBEGIN

DECLARE @outStr VARCHAR(500)EXECUTE capitalize ‘’, @outStr OUTPUTIF @outStr<>’’

EXECUTE tsu_failure ‘Capitalize should return the same value’END

CREATE PROCEDURE capitalize

@inStr VARCHAR(500)=NULL,

@outStr VARCHAR(500)=NULL OUTPUT AS

BEGIN

SET @outStr=NULL

IF @inStr IS NOT NULL

SET @outStr=UPPER(LEFT(@inStr,1))+RIGHT(@inStr,LEN(@inStr)-1)

END

16A testing framework for Microsoft SQL-Server, Jorge Almeida, Dezembro 2006

Test Results

17A testing framework for Microsoft SQL-Server, Jorge Almeida, Dezembro 2006

Improving tests

• Organize tests in classes (suites) (e.g. rename ut_CapitalizeEmptySentence as ut_Capitalize_EmptySentence then run the store procedure tsu_runTest ‘Capitalize’)

• Create a unique procedure for test setup (e.g. ut_Capitalize_SetUp)

• Create a unique procedure for test “teardown” (e.g. ut_Capitalize_TearDown)

18A testing framework for Microsoft SQL-Server, Jorge Almeida, Dezembro 2006

Conclusions

• Good unit testing tool for Microsoft SQL-Server stored procedures

• Regression test suite• Some improvements needed (e.g.

execution time of a single test)

• Be careful with error treatment in test store procedures

19A testing framework for Microsoft SQL-Server, Jorge Almeida, Dezembro 2006

References

• http://sourceforge.net/projects/tsqlunit• http://www.tassq.org

• http://www.agile.org/essays/databaseTesting.html

• http://www.ambysoft.com/books/refactoringDatabases.html• http://www.ambysoft.com/books/agileDatabaseTechniques.html

20A testing framework for Microsoft SQL-Server, Jorge Almeida, Dezembro 2006

Questions ?