Interviewer
Hi, Shivika.
candidate
Hello.
Interviewer
Yeah, Hi. So how much relevant experience do you have in Power BI?
candidate
So I have around 3.5 years experience.
Interviewer
OK. And how much will you rate yourself out of 10?
candidate
So rate myself 8 out of 10 in Power BI.
Interviewer
OK, fine. OK, let's start with the first question. So suppose you are in Power Query Editor. So if we have two or more queries that you want to append, So what should be the like? What should be the minimal condition to append those two queries?
candidate
OK, so I have two queries you need to append right? OK so I think so you can just append it. The one thing that should be there is they should have same number of columns and if they don't have same number of columns I think that there will be a problem that you'll have you know? If there are extra columns in either of them, the other table will show nulls. Yeah, I think so. Yeah, that's that's the only thing that's required.
Interviewer
OK, so only the number of columns should be same. And what about their data types if the data types do not?
candidate
Yeah, yeah yeah no, no no. Their data type should also be the same. So you know the number of columns should be same, the name should be same and the data type should be same. So if there's some extra columns you know in either of them or if the data type or name is different. Then you know they'll consider it as a new, new column. So you're not. They'll take nulls. So, like, these are the three basic things that you do that we have taken. Take care.
Interviewer
OK. And have you heard about query folding?
candidate
Yeah, so query folding is something you know. What happens is if you're using some database as a source. I know SQL as as like for SQL I'm sure of. You know if you there are some transformations that can be done in the SQL side it will be faster because you know SQL is made for that. For the tram those things maybe somewhere clause or some you know some columns some some things. So query folding happens in Power BI, you know it automatically happens. In Power BI, if you have SQL as the source and if you've written your query in such a manner that you know if you've used native query, most of the times the query folding happens. So this is, you know, optimization technique that we can use so that you know the processing would be faster. Something like that, yeah.
Interviewer
OK, fine, OK, suppose can you open your chat section? I'm sending something and you have to answer accordingly. OK. So OK, suppose you have a column which contains values like this which I'm sending 0114. OK, something like this you have in all the rows. OK, OK, so as you can see this is a kind of a date, right? Yeah, but you have a column which contains these these, these kinds of records and the data. The data type of that column is number. OK as as they are representing numbers. No if I if I want to convert it to date how will you do that thing?
candidate
Maybe, you know I have never done this, but what we can do is we can go and we can change the data type to date and then once we go you know once we change the data type it is also an option that what kind of data type that you want. So if you maybe you can check it from there that if it is present maybe I think it's written 2022, zero, 114th I think so it's 14th January. 2020 yeah, so we can you know check it there that you know our data is present in this manner that you know first year is present, then month is present and then date is present. There's an option that you know there's an option for this that you know if you want your date to be this in this particular manner you can just check that so it will automatically take OK, this is your year, the first thing is taken as your the 1st 4 digits, the next two digits are taken as month month and then last two digits are taken as the date. So yeah, this.
Interviewer
Is so you are saying so you are saying. If we are going to directly change its data type from number to date, it will work right As for you.
candidate
Yeah, we have to change and we also have to go to the date. You know, once change it, there's an option of, you know, checking what that kind of date is. You know date we are using it's MMDD format or it's your month, your your, your date like that format. So you have to change, you have to check that as well then I think so it can be done. This is what you are, yeah.
Interviewer
So Shavika, suppose you have a column which contains record something like this which I'm sending right now on your chat section. Suppose something like this is written Rupees 1000. Just a second, I'm sending you OK Rupees 1000 something like this five $5000 OK. Something like this, it is written and you have a column like this. Now if I want to take out number of number from this column and create a new column where I will only have the numbers instead of rupees and dollar then how will I create this in power query editor. OK so something like this you have different currencies written with their numerical part something like this that you're that you're seeing on the screen. So how will you take out the number from this column?
candidate
Yeah, like if I think so, if you know, if the currency symbol was present only at one place, I could have or and it was only one currency, you know, I could have used a custom way to split the columns, you know, using a custom delimiter. But can you give me a minute please? I'm just thinking, is that fine? Yeah.
Interviewer
Yeah, sure.
candidate
OK, we can. OK, and we have to do it in Power Query only, correct?
Interviewer
Yeah.
