We Keep Coding

multiple columns in parent to use same child table to save data in JPA

I have a requirement where I have to save employee detail to a child table, employee data remains the same for multiple parent records (columns as well), I want to use the existing child table to insert if not present and update if already present, how I can do that using Spring JPA / hibernate?
Parent Table
|id|project_id|owner_emp_id|developer_emp_id|lead_emp_id|tester_emp_id|
|:---- |:------:| -----:|:---- |:------:| -----:|
| 1 | 100 | emp_10 | emp_20 | emp_20 | emp_30 |
| 2 | 200 | emp_11 | emp_21 | emp_22 | emp_30 |
employee child table
|emp_id|first_name|olast_name|email|phone|
|:---- |:------:| -----:|:---- |:------:|
| emp_10 |..| .. | .. | .. |
| emp_20 | .. | .. | .. | .. |
| emp_30 | .. | .. | .. | .. |
| emp_11 | .. | .. | .. | .. |
| emp_21 | .. | .. | .. | .. |
| emp_22 | .. | .. | .. | .. |
from the above example when saving the child table during 1st record emp_20 data need to save only once. similarly, the 2nd record insert emp_30 already presents an update or ignores saving it, how to do this in JPA?

How to write nested datatable in Cucumber?

I am trying to write a cucumber feature file using data tables. The object that I need to form using the dataTable has a field which requires two fields. Example:
| Name | Owner | Properties.Key | Properties.value |
| Name1 | myself | someKey1 | someValue1 |
| Name2 | robins | someKey2 | someValue2 |
I was wondering if instead of writing it this way, if there's a better way to write the nested objects using dataTables. Something more like SpecFLow. Example:
| Name | Owner | Properties |
| name1 | myself | {nested} |
| name2 | robins | {nested} |
| key | value |
| someKey1 | someValue1 |
| someKey2 | someValue2 |
Or is there any other way to make the nested dataTable??
Also, how will the steps for the table will look like in java?

How do I run a spark sql aggregator cumulatively?

I am currently working on a project with spark datasets (in Java) where I have to create a new column derived from an accumulator run over all the previous rows.
I have been implementing this using a custom UserDefinedAggregationFunction over a Window from unboundedPreceding to currentRow.
This goes something like this:
df.withColumn("newColumn", customAccumulator
.apply(columnInputSeq)
.over(customWindowSpec));
However, I would really prefer to use a typed Dataset for type safety reasons and generally cleaner code. i.e: perform the same operation with an org.apache.spark.sql.expressions.Aggregator over a Dataset<CustomType>. The problem here is I have looked through all the documentation and can't work out how to make it behave in the same way as above (i.e. I can only get a final aggregate over the whole column rather than a cumulative state at each row).
Is what I am trying to do possible and if so, how?
Example added for clarity:
Initial table:
+-------+------+------+
| Index | Col1 | Col2 |
+-------+------+------+
| 1 | abc | def |
| 2 | ghi | jkl |
| 3 | mno | pqr |
| 4 | stu | vwx |
+-------+------+------+
Then with example aggregation operation:
First reverse the accumulator, prepend Col1 append Col2 and return this value, also setting it as the accumulator.
+-------+------+------+--------------------------+
| Index | Col1 | Col2 | Accumulator |
+-------+------+------+--------------------------+
| 1 | abc | def | abcdef |
| 2 | ghi | jkl | ghifedcbajkl |
| 3 | mno | pqr | mnolkjabcdefihgpqr |
| 4 | stu | vwx | sturpqghifedcbajklonmvwx |
+-------+------+------+--------------------------+
Using a UserDefinedAggregateFunction I have been able to produce this but with an Aggregator I can only get the last row.

You don't
My source for this is a friend who has been working on an identical problem to this and has now concluded it's impossible

Set any field once for all the tests in Fitnesse table

I want to set one field in the fitnesse table, only once for all the tests. For example I want to set Operator as + for all the tests in the table.
Below is the regular table.
!|CalculatorFixture |
|Value1|Operator|Value2|calculate?|
|3.0 |+ |5.0 |8.0 |
|2.0 |* |3.5 |7.0 |
I want something like:
!| CalculatorFixture |
|Operator |
|+ |
|Value1|Value2|calculate?|
|3.0 |5.0 |8.0 |
|6.0 |3.0 |9.0 |
|5.0 |2.0 |7.0 |
Any Idea how can I achieve this in the fixture or in the fitnesse table?
FYI, I am using Slim: !define TEST_SYSTEM {slim}

You can set a Java static field in a previous table fixture and then access it in the CalculatorFixture.

You can also pass 'constructor parameters' to scenarios by using having or given as first cell after the scenario name (from FitNesse's tests)
|scenario | myDivision _ _ _|numerator, denominator, quotient|
|setNumerator | #numerator |
|setDenominator | #denominator|
|check | quotient| #quotient |
| myDivision | having |numerator| 12|
| denominator|quotient|
| 3 |4.0 |
| 6 |2.0 |
| 4 |3.0 |

Create dynamic classes / objects to be included in a list

I have a xlsx file, that has some tabs with different data. I want to be able to save each row of a tab in a list. The first thing that comes to mind is a list of lists, but I was wondering if there is another way. I'd like to save that information in a object, with all its benefits, but can't think of a way to generate/create such diverse objects on the fly. The data in the xlsx is diverse and ideally the program is agnostic of any content.
So instead of e.g. create a list for each row, than put that list in another list for each tab and each tab in another list, I'd like to store the information that each row represents in a single object and just have a list of different objects.
A small graphic to visualize the problem :
+--------------------------------------------------------------------+
|LIST |
| |
| +------------------+ +------------------+ +-----------------+ |
| | Class1 | | Class2 | | Class3 | |
| |------------------| |------------------| |-----------------| |
| | var1 | | var1 | | var5 | |
| | var2 | | var2 | | var6 | |
|... | var3 | | | | var7 |...|
| | | | | | | |
| | | | | | | |
| | | | | | | |
| | | | | | | |
| +------------------+ +------------------+ +-----------------+ |
| |
+--------------------------------------------------------------------+

How about a generic class Row which will contain all the information in a row from your file. Then you simply create a list of Rows. Methods for the Row can allow you to get each column.
Without knowing more about the data, you will not be able to write classes to encapsulate it. You could "dynamically" create classes to create new source code. But then the question is, how would you use the new classes?

Well since you want to avoid a "list of lists" kind of solution there would be another way.
This might not be very efficient or fast but I don't have any experience with it, so maybe it isn't too bad. Here's the idea:
For each Row:
Use javassist to create as many fields as needed dynamically that contain each cell's information. Then create an instance of this class and store it in your list of rows. You could also add a field with information about this particular row (e.g. how many fields there are or their names or types or whatever you might need).
The number of fields or methods could also be determined using Reflection.
To get started with javassist there's a tutorial here.
Besides that I don't think there's much to do that does not involve some sort of List<List<SomeType>>