A single MySQL query to combine strings from many rows into a single row and display the corresponding User Id sum in another column?
For this, you can use GROUP_CONCAT(). Use SUM() to add the User Id. Let us first create a table −
mysql> create table DemoTable1960
(
StudentId int,
StudentName varchar(20)
);
Query OK, 0 rows affected (0.00 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable1960 values(100,'Chris');
Query OK, 1 row affected (0.00 sec)
mysql> insert into DemoTable1960 values(101,'Bob');
Query OK, 1 row affected (0.00 sec)
mysql> insert into DemoTable1960 values(102,'David');
Query OK, 1 row affected (0.00 sec)
mysql> insert into DemoTable1960 values(103,'Mike');
Query OK, 1 row affected (0.00 sec)
Display all records from the table using select statement −
mysql> select * from DemoTable1960;
This will produce the following output −
+-----------+-------------+
| StudentId | StudentName |
+-----------+-------------+
| 100 | Chris |
| 101 | Bob |
| 102 | David |
| 103 | Mike |
+-----------+-------------+
4 rows in set (0.00 sec)
Here is the query to combine strings from many rows into a single row and also display the sum of User Ids −
mysql> select sum(StudentId),group_concat(StudentName separator '.') as ListOfStudent from DemoTable1960;
This will produce the following output −
+----------------+----------------------+
| sum(StudentId) | ListOfStudent |
+----------------+----------------------+
| 406 | Chris.Bob.David.Mike |
+----------------+----------------------+
1 row in set (0.00 sec)
Published on 31-Dec-2019 07:19:09
