Core Designer Certificatification-Hands on
Hi!
I am like to know how to merge the tables by making one table as base file, I also gone through the tutorials but I am not yet clarified.
Please support to get detailed idea
thanks in advance!
Answers
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Hello BALA,
To merge tables you need to first think about how you want to merge. Basically, it's either putting one dataset on the top(or buttom) of another one, or putting one dataset next(to the right or left side) to another one.
1: Putting one dataset on the top(buttom) of another
In Dataiku DSS, this operation is called "stack". In order to stack one dataset on top of another, two datasets should have more or less the similar column names.
In DSS, this can be done by Stack recipe.
Here you can see the tutorial about how to use the stack recipe: https://www.youtube.com/watch?v=IQ_gx1_cnTE
2: putting one dataset next to another
In DSS, this operation is called "join". When joining two datasets, you need to keep in mind two things: Join key and Join type.
- Join key
Join key is a shared column(s) in both datasets. When you don't have any common columns in datasets, you cannot join them.
- Join type
Join type is about how you want to keep rows from both datasets after joining. There are several join types, but normally you choose one of the three: left join, inner join, or outer join. But all in all, you need to decide which dataset you want to put on your left and right side.
Left join keeps all the rows from your left side. From the right side dataset, it keeps only the rows with the matching join key. In the example below, the join key is the ID column. Pay attention that the row 3 & 4 from the Table B is dropped because Table A doesn't have them.
Inner Join keeps only the matching rows from both of the right and left datasets.
Outer Join keeps all the rows from both sides. As a result, there will be some blank cells in the output dataset.
Here you can find a tutorial about how to use Join recipe in Dataiku DSS: https://www.youtube.com/watch?v=MfX2ycIDQw8
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It is appreciatable of your solution!
I am also having anaother query!
Thank you In the same dataset how to transform the column from total country data to per capita data.in some columna having total country data but I want only per capita data alone .
Please let me know how to proceed the same
