How to Order Data In SQL Queries Using the TOP Function!

hello and welcome welcome back to the channel today's video is going to be a continuation in the introduction to sql series that we've begun and so far we've taken a look at creating a statement using select from and where to filter data data data out of a table and today what we're going to be looking at is using the order by function as well as top um so so uh let's just dive right into it here essentially what i've done is i've used the query that we've already discussed select all data from employee table no filtering conditions anything else like that and we get jim pam all the way through creed we get the entire uh employee table so what we want to do today we previously have already looked at filtering out by saying where any of these conditions like position is sales and this will give us just the sales people we've already looked at stuff like that but what we're going to look at today is a new piece called order by and this is essentially telling you how the data is going to be viewed so let's say we want to view the entire employee database based on who makes the most money versus the least money you go order by salary and all of a sudden the default way we were seeing it where jim was at the top and then it just went in the order of the data coming in that's no longer true it starts from the lowest salary and goes up to the highest salary and so order buy is super useful when you have data that might be stored alphabetically or it might not have come in exactly when it happened and you need to order something numerically you can order by any column and if it's a string value so if we did order by position then what's kind of nice is we're going to see it groups people from the same division right next to each other and string columns when you go order by are going to be by default alphabetical so now you're saying well when we did order by salary we had the smallest values at the top which is the default is it's going to go in what it calls ascending order sql considers starting at the lowest number and going downward to higher numbers ascending order so if you want to invert that you use the d e s c and that stands for descending and you basically tell the sql query hey now i want to see the highest number at the top and the lowest number at the bottom and so there's the purpose of using order by descending technically you could say order by ascending and that's going to give you what we saw but if you know that this is the default you don't have to worry about it too much if you didn't know that that was the default then it's nice to know that ascending does exist so the inverse of this is true um and then for string variables if you filter a string column descending you're just going to get reverse alphabetical order so you see we go down to creed at the top and and pam at the beginning when we filter by string value so something that i really like to combine this with let's go back to salary and we'll just leave it as the default i like to talk about the select top function as well so top is saying you're only going to get a certain number of them so like let's say we want the top three uh salaries in the office you would build this query and again to get start at the highest number and go down you need to do descending but now what we'll see we only get the three highest earners so if what you're really concerned with in your data set is outliers you could select the top of whatever based on your column conditions and the way you do that is you use top and then the number and then you still put in your column conditions like before so if you didn't want to select everything you could say select top three just the employee name so essentially you need to keep in mind that you still have to have your column conditions but using this top function and then so right here we get the top three salaries if we were to change that back to default we'd get the last three salaries you can use this with any kind of data like dates anything and you use it as a really powerful tool to filter out all the bottom data you can also we'll talk about this in in future videos but you can also use kind of advanced math queries like averages rounding summation and those kinds of things so essentially the order by tool is a great way for organizing your data based on a specific column you want to see and then selecting top whatever is a great way to filter out data if you're only interested in the real extremities so that's this video it's nice short video punch out two really important concepts in sql hopefully you found it useful if you have any questions on this or anything else you've seen on the channel feel free to let me know about in the comments i'll try to get back to you as soon as i can and if you found this or anything else on the channel useful then i really appreciate a liking to subscribe it helps the channel out a lot and as always good luck with your projects and thanks for watching thanks bye