How to Concatenate Strings in MySQL Using GROUP BY?
Using GROUP BY connection string in MySQL
In database management systems, it is often necessary to merge multiple strings into a single string. In MySQL, you can use the GROUP BY
function to achieve this functionality.
The syntax for MySQL string concatenation is as follows:
SELECT id, GROUP_CONCAT(name SEPARATOR ' ') FROM table GROUP BY id;
This query will group the rows by the id
column and concatenate the values in the name
column using the specified separator (space in this case).
Example
Consider the following form:
foo_id | foo_name |
---|---|
1 | A |
1 | B |
2 | C |
To concatenate the foo_id
values for each foo_name
you can execute the following query:
SELECT foo_id, GROUP_CONCAT(foo_name SEPARATOR ' ') FROM foo GROUP BY foo_id;
This query will return the following results:
foo_id | foo_name |
---|---|
1 | A B |
2 | C |
As you can see, each foo_id
value of foo_name
has been concatenated into a single string.
Additional information
-
GROUP_CONCAT
Functions can concatenate any data type, not just strings. - You can specify multiple columns in the
GROUP BY
clause. - You can also specify the order in which values are concatenated.
For more information about the GROUP_CONCAT
function, see the MySQL documentation: https://www.php.cn/link/18fc3b6cc1e55ccea877c161e2e9ba27
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