I have a transformation into Kettle Pentaho called Test.
This ETL process should load three different tables of a single database, where each one has his source into a different table of a another database.
To do this I use three table input steps. Each one connects to a value mapper, this to a Select value step, then a Data Validator, and add sequence step and finally a table output.
Summarising I have a total of six steps per table load.
When I am editing the finals steps I found a thing that I would like to solve, I drag the fields of the previous tables loads.
For example, table A load have the field bank_id, in the second table it does not exist, but in the table output step of the second load process I can select this despite I do not want this.
Is there any option to do not see the previous fields? Thsi way I avoid easy errors. Especially, when the tables have a field with the same name.
Thank you
EDIT
The screenshot clarifies the situation immensely, so now the answer is simple:
Delete the diagonal hops (arrows) between the rows.
Transformations in PDI don't have a single starting or ending point, so you don't need to connect all the steps in a single line. Having three separate streams is just fine.
All steps in a transformation start in parallel, then wait and process rows as they come in (or in the case of input steps, start reading data and generating rows into their output hop). That means your three streams will execute in parallel following their own hops from input to output.
add a Select Values step, i use to add filter steps often to "clean" the flow
Related
Here's a distilled version of what we're trying to do. The transformation step is a "Table Input":
SELECT DISTINCT ${SRCFIELD} FROM ${SRCTABLE}
We want to run that SQL with variables/parameters set from each line in our CSV:
SRCFIELD,SRCTABLE
carols_key,carols_table
mikes_ix,mikes_rec
their_field,their_table
In this case we'd want it to run the transformation three times, one for each data line in the CSV, to pull unique values from those fields in those tables. I'm hoping there's a simple way to do this.
I think the only difficulty is, we haven't stumbled across the right step/entry and the right settings.
Poking around in a "parent" transformation, the highest hopes we had were:
We tried chaining CSV file input to Set Variables (hoping to feed it to Transformation Executor one line at a time) but that gripes when we have more than one line from the CSV.
We tried piping CSV file input directly to Transformation Executor but that only sends TE's "static input value" to the sub-transformation.
We also explored using a job, with a Transformation object, we were very hopeful to stumble into what the "Execute every input row" applied to, but haven't figured out how to pipe data to it one row at a time.
Suggestions?
Aha!
To do this, we must create a JOB with TWO TRANSFORMATIONS. The first reads "parameters" from the CSV and the second does its duty once for each row of CSV data from the first.
In the JOB, the first transformation is set up like this:
Options/Logging/Arguments/Parameters tabs are all left as default
In the transformation itself (right click, open referenced object->transformation):
Step1: CSV file input
Step2: Copy rows to result <== that's the magic part
Back in the JOB, the second transformation is set up like so:
Options: "Execute every input row" is checked
Logging/Arguments tabs are left as default
Parameters:
Copy results to parameters, is checked
Pass parameter values to sub transformation, is checked
Parameter: SRCFIELD; Parameter to use: SRCFIELD
Parameter: SRCTABLE; Parameter to use: SRCTABLE
In the transformation itself (right click, open referenced object->transformation):
Table input "SELECT DISTINCT ${SRCFIELD} code FROM ${SRCTABLE}"
Note: "Replace variables in script" must be checked
So the first transformation gathers the "config" data from the CSV and, one-record-at-a-time, passes those values to the second transformation (since "Execute every input row" is checked).
So now with a CSV like this:
SRCTABLE,SRCFIELD
person_rec,country
person_rec,sex
application_rec,major1
application_rec,conc1
status_rec,cur_stat
We can pull distinct values for all those specific fields, and lots more. And it's easy to maintain which tables and which fields are examined.
Expanding this idea to a data-flow where the second transformation updates code fields in a datamart, isn't much of a stretch:
SRCTABLE,SRCFIELD,TARGETTABLE,TARGETFIELD
person_rec,country,dim_country,country_code
person_rec,sex,dim_sex,sex_code
application_rec,major1,dim_major,major_code
application_rec,conc1,dim_concentration,concentration_code
status_rec,cur_stat,dim_current_status,cur_stat_code
We'd need to pull unique ${TARGETTABLE}.${TARGETFIELD} values as well, use a Merge rows (diff) step, use a Filter rows step to find only the 'new' ones, and then a Execute SQL script step to update the targets.
Exciting!
I have a table input and I need to add the calculation to it i.e. add a new column. I have tried:
to do the calculation and then, feed back. Obviously, it stuck the new data to the old data.
to do the calculation and then feed back but truncate the table. As the process got stuck at some point, I assume what happens is that I was truncating the table while the data was still getting extracted from it.
to use stream lookup and then, feed back. Of course, it also stuck the data on the top of the existing data.
to use stream lookup where I pull the data from the table input, do the calculation, at the same time, pull the data from the same table and do a lookup based on the unique combination of date and id. And use the 'Update' step.
As it is has been running for a while, I am positive it is not the option but I exhausted my options.
It's seems that you need to update the table where your data came from with this new field. Use the Update step with fields A and B as keys.
actully once you connect the hope, result of 1st step is automatically carried forward to the next step. so let's say you have table input step and then you add calculator where you are creating 3rd column. after writing logic right click on calculator step and click on preview you will get the result with all 3 columns
I'd say your issue is not ONLY in Pentaho implementation, there are somethings you can do before reaching Data Staging in Pentaho.
'Workin Hard' is correct when he says you shouldn't use the same table, but instead leave the input untouched, and just upload / insert the new values into a new table, doesn't have to be a new table EVERYTIME, but instead of truncating the original, you truncate the staging table (output table).
How many 'new columns' will you need ? Will every iteration of this run create a new column in the output ? Or you will always have a 'C' Column which is always A+B or some other calculation ? I'm sorry but this isn't clear. If the case is the later, you don't need Pentaho for transformations, Updating 'C' Column with a math or function considering A+B, this can be done directly in most relational DBMS with a simple UPDATE clause. Yes, it can be done in Pentaho, but you're putting a lot of overhead and processing time.
I'm still relatively new to SQL and Pentaho.
I've pulled a table with two different IDs and need to run a query for each specific instance.
For example,
SELECT *
FROM Table
WHERE RecordA = 'value in column A'
AND RecordB = 'value in column B'
I need the results back, either appended to new columns in the original table or part of their own text file output.
I was initially looking at using a formula for this inside of Pentaho, but couldn't quite figure it out. Since I have the query written I threw it into Excel and got the concatenated results (so a string of 350 or so queries that I need to run). I'm just not sure how to accomplish this - I tried the Execute SQL Script inside of Pentaho but it doesn't seem to do output?
Any direction would be useful. I've searched a little but have come up short so far, possibly because I am still pretty new to this platform.
You can accomplish this behavior in a lot of ways, with a "Database Lookup" step for example, but I usually do that in a quite easy way and here is a example for your tests, I hope it helps.
The idea here is to have two Table input steps, the first one will fetch the IDs we want to look at. For example you may use a SQL query similar to note on the left. The result will be a 1 column stream of rows.
Next we have a Table Input that reads the rows received and executes it's query for each row. I'll add a screenshot with the options that I selected.
What it does is replace a placeholder '?' with the data that is received. If you need two columns use two '?' but remember that it will replace the first one with the first column and the second one with the second column
And you are good to go. Test it a couple of times and good luck.
And the config for the second table input.
I'm doing a transformation in kettle and I need to send data to another transformation, for this use a step "copy rows to result", but this step I do half the processing and need to add more data to the end of the transformation, as might do?.
Greetings and thanks
EDIT 24-06-2014
This image is the example of my transformation:
The only thing you need to make sure when merging the results from multiple streams in Kettle is that the columns from both hops to Copia Filas (Copy rows to result in the English version) are completely identical, meaning:
The number of columns sent to the final step is equal;
The column types are completely identical;
The column names are completely identical;
Kettle should alert if otherwise.
If this is not the issue, you should check that the second stream in the data distribution actually generates the data you want to merge into the final step of the transformation, depending on what you'd like to do there.
Use the preview and debug options, as well as the right click (on a step) ==> Show output fields in Kettle to make sure all of the above are happening.
I hope this helps a bit.
I'm trying to split a table into multiple tables based on the value of a given column using Talend Open Studio. Let's say this column can contain any of the integer values of 1, 2, 3, etc. then according to this value, these rows should go to table_1, table_2, table_3 etc.
It would be best if I could solve this when the number of different values in that column is not known in advance, but for now we can assume that all these output tables exists already. The bottom line is that the number of different values and therefore the number of different tables are high enough that setting up the individual filters manually is not an option.
Is this possible to solve this using Talend Open Studio or any similiary open source ETL tools like Pentaho Keetle?
Of course, I could just write a simple script myself, but I would prefer to use a proper ETL tool since the complete ETL process is quite complex.
In PDI or Pentaho Kettle you could do this with partitioning. (A right click option on the step IIRC) Partitioning in PDI is designed for exactly this sort of problem.
Yes that's Possible to do and split the data on the basis of single column to different table, but for that you need to create table dynamically :-
tFileInputDelimited->tFlowtoIterate ->tFixedFlowInput->and the can use
globalMap() to get the column values and use the same to seperate the
data to different tables. -> And the can use globalMap(Columnused to
seperate data) in table name.
The first solution that came to my mind was using the replicator to transport the current row to three filters which act as guard and only let rows through with either 1 2 or 3 in the given column. pic: http://i.imgur.com/FmvwU.png
But you could also build the table name dynamically, if that is what you want, pic: http://i.imgur.com/8LR7Q.png