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DbFit - Automated Open Source Database Testing

Yavor Nikolov, Luxoft, @javornikolov, https://javornikolov.wordpress.com/

DbFit is an open source tool for automated database testing. Gojko Adzic initially created this tool with the goal to enable efficient database testing Ė in order to motivate database developers to use an automated testing framework. DbFit is based on the FitNesse framework that enables defining tests in readable and easy to maintain tabular format. It supports many relational databases, including Oracle, MS SQL Server, MySQL, PostgreSQL and others.

Web site: http://dbfit.github.io/dbfit/
Version tested: 3.2.0
System requirements: Java Runtime Environment 7 or higher
License and Pricing: Free and Open Source, GPL v2
Support: DbFit Google group (http://groups.google.com/group/dbfit) and GitHub issue tracker (https://github.com/dbfit/dbfit/issues)

Getting Started

Installation

To run DbFit you need Java Runtime Environment (JRE) 7 or higher which you may get from Oracle web site. Also youíll need to ensure the accounts and connectivity to the databases which you want to access with DbFit.

To install DbFit you can download it from its web site http://dbfit.github.io/dbfit/ unpack the archive and run startFitnesse.sh or startFitnesse.bat (depending on your operating system). It may take it a few seconds to start the server and then you can access it using your browser at http://localhost:8085/. You'll be able to access some built-in reference documentation and examples from that web page.

Creating a new test page

Open http://localhost:8085/HelloWorldTest in your browser. You should see an editor where you can create and run your test page.

Test pages are described in the FitNesse Wiki syntax that is essentially a simple text format for describing commands in terms of tables. The premise is that this notation is close to relational model, so that you don't need to know Java or other lower-level programming language to create DbFit tests.

Test pages may be grouped in suites that may be organized in hierarchical structure. The names of test pages and suites should be CamelCase.

Although the FitNesse Wiki syntax is really simple, you do not have to use it to write scripts. You can write your tables in Excel (or almost any other spreadsheet program), and then just copy or import them into the FitNesse page editor.

Test pages are stored on the file system in simple text format. You can create and edit them directly using your favorite text editor.

Running tests

To run a test page, you can click the Test button in FitNesse. It is possible to run all tests within a suite and it is also possible to trigger tests execution via REST API, JUnit or a command line allowing you to automate running DbFit tests and integration with a continuous integration (CI) server.

Configuration

For details about configuring different port number, project folder or other settings you may examine the startFitnesse script and its --help option output, plugins.properties file, and also consult FitNesse documentation.

Due to licensing restrictions, the drivers of some of the supported databases are not shipped with DbFit. You will need to provide the required additional JDBC driver jar files by copying them into DbFit lib folder.

In order to load the DbFit extension into FitNesse, your test pages have to load the correct libraries by including the following command:

!path lib/*.jar

This command can be placed directly into a test page or in a parent page in the test suite hierarchy.

Connecting to the database

DbFit supports two modes of operation: Flow and Standalone. By default, each individual test page in flow mode is executed in a transaction that is automatically rolled back after the test. In the standalone mode, you are responsible for overall transaction control. Most of the commands are common for both modes, but there are some limitations in standalone mode a different syntax for opening a connection.

Here is how to connect to a MySQL database in flow mode:

!|dbfit.MySqlTest|
!|Connect|localhost|dbfit_user|password|dbfit|

Notice the MySqlTest in the first line above. That tells DbFit which type of database driver to use. The second line defines connection properties. These two lines will typically be the first on every test page.

And here is how to open a connection in standalone mode:

|import fixture|
|dbfit.fixture|
!|DatabaseEnvironment|MySql|
|Connect|localhost|dbfit_user|password|dbfit|

There is support for configuring the connection details in separate file. Encryption of the database password is also supported so that you can avoid storing it in plain text.

Supported databases

The following database systems are currently supported by DbFit: Oracle, SQL Server, MySQL, Postgres, Derby, HSQLDB, DB2, DB2i, Teradata, Netezza, Informix.

Basic cycle of a DbFit test and its execution

  1. Set up the input data and other context. The following DbFit commands are typically used at this stage: Insert, Update, ExecuteDdl, Execute. If common setup steps are used by several tests - it may be useful to keep them in SetUp page that will be automatically included in the beginning of the other tests in the suite.
  2. Execute a database operation that you want to test (typically - a stored function or procedure, or an external process such as an ETL tool routine). Useful DbFit commands: Execute Procedure.
  3. Verify the result - comparing the actual versus the expected result. Useful DbFit commands: Query, Store Query, Compare Stored Queries
  4. Tear Down - clean up the changes in order to avoid affecting other tests. Pages named TearDown are automatically included at the end of all tests in the suite. In Flow mode, the active transaction is automatically rolled back at the end of the test page so often you won't need any explicit tear down steps (assuming you don't commit transactions in your tests).

Quick reference of the mostly used commands

Query

The Query command allows you to compare the result of a SQL Query to a given expected output. You should specify query as the first fixture parameter, after the Query command. The second table row contains column names, and all subsequent rows contain data for the expected results. You don't have to list all columns in the result set, just the ones that you are interested in testing. Multiple columns and rows are supported.

!|Query|select 'test1' as column_one, 'test2' as column_two from dual|
|column_one |column_two|
|test1 |test2 |

As output of the Query command execution, matches are marked in green and mismatches are highlighted in red. In case of any mismatch - the test is counted as failing. Missing or unexpected surplus records are also being reported as mismatch.

Ordered Query is a variation of Query command that takes into account the exact ordering of rows.

Store Query, Compare Stored Queries

Store Query reads out query results and stores them into a Fixture symbol for later use. Specify the full query as the first argument and the symbol name as the second argument (without >>). You can then use this stored result set as a parameter of the Query command later:

!|Store Query|select n from (select 1 as n from dual union select 2 from dual union select 3 from dual)|firsttable|
!|Query|<<firsttable|
|n |
|1 |
|2 |
|3 |

Compare Stored Queries compares two previously stored query results. Column structure is specified so that some columns can be ignored during comparison (just donít list them), and for the partial row-key mapping to work. Put a ? after the column names that do not belong to the key to make the comparisons better.

|Store Query|select n, name from testtbl|fromtable|
|Store Query|!- select 1 n, 'name1' name from dual|fromdual|
|Compare Stored Queries|fromtable|fromdual|
|name |n? |

Typically you should strive for fast and focused tests, comparing just a small amount of records. Nevertheless, in some special cases you could want to run DbFit on top of a relatively large number of rows. Please refer to the DbFit reference guide for some guidelines how to handle such scenarios more efficiently.

DML and DDL statements

Insert

Insert command allows inserting a set of records into a database table (or view). The view or table name is given as the first fixture parameter. The second row contains column names, and all subsequent rows contain data to be inserted. For example:

!|Insert|testtbl|
|id |name |
|1 |NAME1 |
|3 |NAME3 |
|2 |NAME2 |

Update

Update allows you to update specified records in a database table or view. Columns ending with = are used to update records. Columns without = are used to select rows. The following example updates the name column where the id matches 1 and 2.

!|Update |testtbl|
|name= |id |
|New Name1|1 |
|New Name2|2 |

You can use multiple columns for both updating and selecting, and even use the same column for both operations.

Execute and Execute Ddl

Execute executes SQL statement provided using the syntax relevant for the database. You can use query parameters in the DB-specific syntax (eg. @paramname for SQLServer and MySQL, and :paramname for Oracle). Currently, all parameters are used as inputs, and there is no option to persist any statement outputs.

!|Execute|alter session set ddl_lock_timeout=600|
!|Set Parameter|name|Darth Maul|
!|Execute|insert into test_table(name, age) values (:name, 10)|

Execute Ddl is intended for executing DDL SQL statements (like create, alter, drop). It's similar to Execute with the main difference that it does not support bind variables, and also automatically handles required post-execute activities, if any (e.g. Teradata requires transaction to be closed after each DDL statement).

!|Execute Ddl|create table tab_with_trigger(x int)|
!|Execute Ddl|create or replace trigger trg_double_x before insert on tab_with_trigger for each row begin :new.x := :new.x * 2; end;|
!|Insert|tab_with_trigger|
|x |
|13 |
!|Query|select x from tab_with_trigger|
|x |
|26 |

Execute Procedure

Execute Procedure executes a stored procedure or function for each row of data table, binding input/output parameters to columns of the data table, e.g.:

!|Execute Procedure|ConcatenateStrings |
|first_string|second_string|concatenated?|
|Hello |World |Hello World |
|Ford |Prefect |Ford Prefect |

If a function is getting called, then a column containing just the question mark is used for function results.

!|Execute Procedure|ConcatenateF |
|first_string|second_string|? |
|Hello |World |Hello World |
|Ford |Prefect |Ford Prefect|

To use IN/OUT parameters, you will need to specify the parameter twice. Once without the question mark, when it is used as the input; and one with the question mark when it is used as output:

|Execute Procedure|Multiply|
|factor|val|val? |
|5 |10 |50 |

To determine the test result, the actual output and return values are compared with the specified expected ones.

There is a variant Execute Procedure Expect Exception in case you expect your stored procedure to raise an exception.

Parameters and fixture symbols

DbFit enables you to use Fixture symbols as global variables during test execution, to store or read intermediate results. In order to store a parameter from a Query or Execute Procedure - you can use >>parameter syntax, and <<parameter to read the value. In addition, you can use the Set Parameter command to explicitly set a parameter value to a string.

!|Set Parameter|ONE|1|
!|Query|select sysdate mytime from dual|
|mytime? |
|>>current_time |
!|Query|select '1' as cnt from dual where sysdate >= :current_time|
|cnt |
|<<ONE |

Advanced use cases

Depending on your needs, you may find out that you need a functionality that is beyond what is currently supported by DbFit. These are more advanced use cases which are out of scope of this article, we will just outline two possible extension points:

  • You can integrate other Fit fixtures in our tests - e.g. to run an external application which loads a file into the database.
  • You may also extend DbFit by developing your custom fixtures or database adapters.

Contributing to the project

DbFit is open for contribution: whether you'd like to extend the functionality, fix a bug, improve the documentation, suggest an idea, report a problem, ask a question, or share a feedback. You may submit your issue or open a pull request at GitHub or you can post your question in the mailing list. Check out the project on GitHub and the published CONTRIBUTING guidelines for more details.

Some limitations

  • User defined abstract database types are not fully supported.
  • The declarative syntax might be insufficient if you need low level control in your tests, coding some logic, testing behavior of multiple concurrent connections: DbFit syntax may be insufficient. For more complicated scenarios you may need to develop your custom fixtures or to use other tools for the purpose.
  • It is not intended for performance testing, even if there are some guidelines if you need to compare larger datasets.
  • FIT runner is required, Slim is not supported.

Some Benefits

  • Support for multiple database types (Oracle, SQL Server, etc.)
  • Readable and easy to understand syntax that enhance communication with non-technical people
  • Open source, open for extension, contribution, suggestions and feedback
  • An active community mailing list where you can get support from other users and contributors
  • Online documentation with examples enabling you to easily get started

Conclusion

When appropriately used, DbFit can help improving the quality, design and maintainability of your product. It enables Agile practices like Test-Driven Development, refactoring. DbFit tests can be used as living executable documentation of your system behavior.

References

DbFit web site - http://dbfit.github.io/dbfit

DbFit at GitHub - https://github.com/dbfit/dbfit

A presentation and demo about TDD with DbFit and Oracle - https://github.com/javornikolov/tdd-with-dbfit-bgoug-201305

FitNesse framework - http://www.fitnesse.org

Fit and Slim test systems - http://fitnesse.org/FitNesse.FullReferenceGuide.UserGuide.WritingAcceptanceTests.TestSystems

Java download page - http://www.oracle.com/technetwork/java/javase/downloads/index.html


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This article was originally published in the Fall 2016 issue of Methods & Tools

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