How to compare two query result and create one dynamic colum

Question

I have two mysql query result, both result having same colum based on some conditions.

I have to check the value in the first result column is present in the second result column. If it is there i have to create new column value as 1, else it is 0. How can i do this

Answer 1

There is a perfect way while using flag to detect whether someone is already logged in or not and in case if System get power off , you need an event handler called as SystemEvents.SessionEnds.

 

Use this to change the flag value from true to false

 

Use this link as a reference

https://stackoverflow.com/questions/6799955/how-to-detect-windows-shutdown-or-logoff 

Answer 2

Hey Ajeesh

 

one more question... ??

 

If power off happen then how you suppose to Reset the flag

 

Answer 3

You can take a look at this article which discuss a similar topic. 

 

https://blog.learningtree.com/preventing-duplicate-logins-in-asp-net/

 

Another option would be to have a flag in your table and set the value to true when an user login and when user log off set the value to false.  Also for when a second user tries to login we will first check if login flag has been set to true for any other user. If its true then show message to user and display the login page, if not allow the user to login.