A testing framework for Microsoft SQL-Server

A testing framework for Microsoft SQL-Server Jorge Almeida

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

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

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

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

Database testing tools Category of database testing (interface and internal) Support the language of developing Help putting the database into a known state

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 test Unit testing tools Examples Description Category

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)

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

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

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

Test example (1) CREATE PROCEDURE ut_CapitalizeOneSentence AS BEGIN DECLARE @outStr VARCHAR (500) EXECUTE capitalize ‘ a string ’ , @outStr OUTPUT IF 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

Test example (2) CREATE PROCEDURE ut_CapitalizeNullSentence AS BEGIN DECLARE @outStr VARCHAR (500) EXECUTE capitalize NULL , @outStr OUTPUT IF @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

Test example (3) CREATE PROCEDURE ut_CapitalizeEmptySentence AS BEGIN DECLARE @outStr VARCHAR (500) EXECUTE capitalize ‘’ , @outStr OUTPUT IF @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

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)

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

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

A testing framework for Microsoft SQL-Server

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