---
{
    "title": "GROUP_CONCAT",
    "language": "en"
}
---

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# group_concat
## description
### Syntax

`VARCHAR GROUP_CONCAT(VARCHAR str[, VARCHAR sep])`


This function is an aggregation function similar to sum (), and group_concat links multiple rows of results in the result set to a string. The second parameter, sep, is a connection symbol between strings, which can be omitted. This function usually needs to be used with group by statements.

## example

```
mysql> select value from test;
+-------+
| value |
+-------+
| a     |
| b     |
| c     |
+-------+

mysql> select GROUP_CONCAT(value) from test;
+-----------------------+
| GROUP_CONCAT(`value`) |
+-----------------------+
| a, b, c               |
+-----------------------+

mysql> select GROUP_CONCAT(value, " ") from test;
+----------------------------+
| GROUP_CONCAT(`value`, ' ') |
+----------------------------+
| a b c                      |
+----------------------------+

mysql> select GROUP_CONCAT(value, NULL) from test;
+----------------------------+
| GROUP_CONCAT(`value`, NULL)|
+----------------------------+
| NULL                       |
+----------------------------+
```
## keyword
GROUP_CONCAT,GROUP,CONCAT