How does SQL combine multiple rows into one row of data

This article mainly introduces "how SQL combines multiple rows into one row of data". In daily operation, I believe many people have doubts about how SQL combines multiple rows into one line of data. The editor consulted all kinds of materials and sorted out simple and easy-to-use methods of operation. I hope it will be helpful for you to answer the question of "how SQL combines multiple rows into one line of data". Next, please follow the editor to study!

Background:

If there is a table named STUDENTS

SubjectID StudentName

-- 1 Mary

1 John

1 Sam

2 Alaina

2 Edward

My expected result is:

SubjectID StudentName

-1 Mary, John, Sam

2 Alaina, Edward

You can use SQL statements as follows:

Using group_concat to complete

The sql statement is as follows:

SELECT SubjectID,GROUP_CONCAT (StudentName)

FROM default_db.odl_group_concat_sample

Group by SubjectID at this point, the study on "how SQL combines multiple rows into one row of data" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!