AND is used in a WHERE clause or a GROUP BY HAVING clause to limit the rows returned from the executed statement. Use AND when it’s required to have more than one condition met.
We’ll use the student table to present examples.
Here’s the student table without a WHERE clause:
select * from student;
Now the WHERE clause is added to display only programming students:
select * from student where programOfStudy = 'Programming';
Now the WHERE clause is updated with AND to show results for programming students that also have a SAT score greater than 800:
select * from student where programOfStudy = 'Programming' and sat_score > 800;
This is a more complex example from the campaign contributions table. This example has a GROUP BY clause with HAVING clause using an AND to restrict the returned records to candates from 2016 with contributions between $3 Million and $18 Million in total.
select Candidate, Office_Sought, Election_Year, FORMAT(sum(Total_$),2) from combined_party_data where Office_Sought = 'PRESIDENT / VICE PRESIDENT' group by Candidate, Office_Sought, Election_Year having Election_Year = 2016 and sum(Total_$) between 3000000 and 18000000 order by sum(Total_$) desc;