SQL | Delta Records in SQL | Difference between two tables using SQL | Delta Record | Using 3 method

Delta record is the incremental (updated or inserted) load of data that is inserted or updated into a table in the database.
Delta detection compares new data from a source system with the last versions in the data warehouse to find out whether a new version has to be created.
In this video I have written SQL query to compare two tables with the same schema and found the new/modified records when comparing the two tables.
Feel free to send mail to [e-mail] for any clarification.

[@sharkane10]

Thank you for your explanation. It was very helpful to me.

[@dataprojecthub]

Thanks Mark😊

[@mohammadmamun5193]

Thanks for the video,if I want to compare in a single table when any row added,display the date added.
For example if yesterday John added on the table I wanna display yesterday's date and keep displaying the date for until it stays.how to achieve it

[@SurajMishra91]

Which one should be good considering performance on millions of rows?

[@aniketkatre4627]

Thanks,
If possible will you create a video on how to remove duplicate records from table. Based on primary key column please.......

[@krishnakishore993]

hi
Your explanation was awesome,
i have one small doubt, can u explain little bit meaning of select 1.

[@dataprojecthub]

Thanks Krishna!
The EXISTS/NOT EXISTS operator is used to test for the existence/absence of any record in a subquery. ie, EXIST/NOT EXIST operator will look for a TRUE or FALSE. Every row-column of the external query will get compared with the specific column that we are giving in the where clause in the exists. For every row-column the specific where condition is checked and if the condition satisfies then the query for exist s will return a TRUE or else FALSE.
Whatever we are putting inside the SELECT clause for exists does not matter here. So even if you change '1' to a column name it will work.