versioned_docs/version-2.1/sql-manual/sql-functions/aggregate-functions/group-array-intersect.md

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

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## group_array_intersect
### description
#### Syntax

`expr GROUP_ARRAY_INTERSECT(expr)`

calculate the intersect element from all arrays given, return a new array

### example

```
mysql> select c_array_string from group_array_intersect_test where id in (18, 20);
+--------------------------------+
| c_array_string                 |
+--------------------------------+
| ["a", "b", "c", "d", "e", "f"] |
| ["a", null]                    |
+--------------------------------+
2 rows in set (0.02 sec)

mysql> select group_array_intersect(c_array_string) from group_array_intersect_test where id in (18, 20);
+---------------------------------------+
| group_array_intersect(c_array_string) |
+---------------------------------------+
| ["a"]                                 |
+---------------------------------------+
1 row in set (0.03 sec)
```

### keywords
GROUP_ARRAY_INTERSECT, ARRAY