Hello, sir. In the first case (4:15) it really works as a true/false condition. No matter what is in the subquery, if it is true, then the main query is executed, and it returns all values from the table. While in the second case (6:46), the result of the main query is limited by the values that are returned by the subquery. Why is that? Please help me understand.
If output is true then it return all rows of first relation which is the first case in above video..... If output is resultset then left side query output is filter with result of sub query... Hope it solve your doubt
please watch this video and your doubt will be cleared. It is related to how nested subquery and correlated subquery work. In the case of exists/not exists, first the outer query runs row by row and for every row of the outer query, the inner query has to run those many times (basically the subquery is not just executed once). ua-cam.com/video/wA9GJZcB618/v-deo.html&ab_channel=GateSmashers
@@noor4937 the second example is of a corelated subquery(2 tables in subquery with one table also being present in the outside query). in that case the only rows that meets condition are returned. the first case is a simple subquery where the inside and outside query have same table
Hi sir, The explanation overall is good. But one doubt that I am not able to figure out yet, in which video did you create the Orders table and how is a primary column of table Employees linked with that of orders?
Haan sir, kr diya dislike and report. One of the worst explanation I have seen on the topic. You just read the definition and did not show the step-by-step execution. Lean to teach.
I wish you could have little patience to wait and see the full video 😀, it contains demo as well, please have patience if you want to learn something. Anyways, thanks for your awesomeness and support without even watching the full video 😀
Hello, sir. In the first case (4:15) it really works as a true/false condition. No matter what is in the subquery, if it is true, then the main query is executed, and it returns all values from the table. While in the second case (6:46), the result of the main query is limited by the values that are returned by the subquery. Why is that? Please help me understand.
If output is true then it return all rows of first relation which is the first case in above video.....
If output is resultset then left side query output is filter with result of sub query...
Hope it solve your doubt
@@ravindravyasit123 In the first case also there is a result set(1 row) for the sub query but the main query is not limited by it.
please watch this video and your doubt will be cleared. It is related to how nested subquery and correlated subquery work. In the case of exists/not exists, first the outer query runs row by row and for every row of the outer query, the inner query has to run those many times (basically the subquery is not just executed once). ua-cam.com/video/wA9GJZcB618/v-deo.html&ab_channel=GateSmashers
@@noor4937 the second example is of a corelated subquery(2 tables in subquery with one table also being present in the outside query). in that case the only rows that meets condition are returned. the first case is a simple subquery where the inside and outside query have same table
Great Explanation. Thank you.
Can I have the sample database which you are using here in the example?
Hello Sir, I was able to understand it thank you
thank you so much. After 2 minutes of video I understood everything
Glad it helped! Keep watching and sharing.
thank you so much for brief lecture sir!
Hi sir,
The explanation overall is good.
But one doubt that I am not able to figure out yet, in which video did you create the Orders table and how is a primary column of table Employees linked with that of orders?
exactly
Beautifully Explained! Thank you
really helpful, clean explain and easy to understand!! thank you sir❤
Thanks lot it's very helpful
Thank you so much ❤
Excellent explanation sir
Thanks Sir. You have made it really lucid.
Glad to hear that!
Keep watching for more videos and tutorials.
thanks for ur video
Really well explained sir...thank you🎉
Glad you liked it! Keep watching and sharing.
Thanks you sir i can easily understand please do more vedioes
Could you please share with us the used database?
Useful 👍
do you use EXISTS only in a subquery or there are other use cases? thanks
I use it in Stored procedure
thank you
You're welcome
Amazing tutorial thank you so much it was helpful
If I execute the last example subquery seperately we are not getting any values but with WHERE EXISTS we are getting values. Can you please Explain?
Explaining exists and not exists by using select * is the worse combination for students to understand
right...what right???
Haan sir, kr diya dislike and report.
One of the worst explanation I have seen on the topic. You just read the definition and did not show the step-by-step execution. Lean to teach.
I wish you could have little patience to wait and see the full video 😀, it contains demo as well, please have patience if you want to learn something. Anyways, thanks for your awesomeness and support without even watching the full video 😀