The Testing Blog

Wrapping my mind around Slim Query Tables

Posted on September 18, 2009. Filed under: test automation |

I started using the Slim test framework (the .NET implementation) about two weeks ago, but had worked primarily with scenario, script , and decision tables up until yesterday. (Scenario tables ROCK btw and I will blog about them soon).

Yesterday I started working on an automated test (or, if you prefer, collection of checks) that needed to verify data in a result set, so I started learning about the Slim Query table. The query table example and corresponding fixture code presented in the FitNesse user guide are fairly straightforward. The part that I really had to wrap my head around was the statement “The fixture class must have a query method that returns a list of rows. Each row is a list of fields. Each field is a two-element list composed of the field name and its string value.” Say whaaat?

Now, maybe for those of you who have more of a programming background than I do, you might have read that statement and immediately pictured what the Query results “look” like. I didn’t. I’m used to thinking of query results as a table, not as lists of lists. I had to create a visual.

Given this result set:

Starting at the lowest level, we have “Each field is a two-element list comprised of the field name and its string value.” OK, so for row 0 column 0 we’d have:

For row 0 column 1 we’d have:

etc.

Let’s go up a level. “Each row is a list of fields.” That makes sense now. For row 0 we’d have:

Finally, the Query method “returns a list of rows.” Ohhh now it makes sense.

Hmm…but then I had to figure out how to translate a DataTable result set into the list of this format. It was actually pretty simple; iterate through the rows and columns to create what I call column-value pairs, collect each row’s column-value pairs into a list, then collect the rows into a list.

I’ve provided my solution below (sorry about the formatting – this theme’s code tag sucks).

It’s a method that takes a DataTable and creates the list of lists of column-value pairs that will work with Slim Query tables. So, in each Slim Query Fixture class, I just call off to the method and pass in the DataTable of results, then return the list of lists of column-value pairs from the Query() method.


using System;
using System.Collections.Generic;
using System.Data;
using System.Text;


namespace Your.Namespace.Here
{
public static class SlimQueryResultsHelper
{
// Convert a result set in DataTable format to the format required by the Slim Query test table
public static List ConvertDataTableToObjectList(DataTable theTable)
{
List queryResults = new List();
foreach (DataRow row in theTable.Rows)
{
List rowListOfColumnValuePairs = new List();
foreach (DataColumn col in theTable.Columns)
{
List columnValuePair = new List();
object val = row[col];
columnValuePair.Add(col.ColumnName);
columnValuePair.Add(val == DBNull.Value ? "null" : val);
rowListOfColumnValuePairs.Add(columnValuePair);
}
queryResults.Add(rowListOfColumnValuePairs);
}
return queryResults;
}
}
}


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