array_distinct

Description

Removes duplicate elements from an array.

Syntax

array_distinct(array)

Parameters

array: the array from which you want to remove duplicate elements. Only the ARRAY data type is supported.

Return value

Returns an array.

Usage notes

• The elements of the array that is returned may be sorted in a different order than the elements of the array that you specify.

• The elements of the array that is returned are of the same data type as the elements of the array that you specify.

Examples

In this section, the following table is used as an example:

mysql> select * from test;

+------+---------------+

| c1   | c2            |

+------+---------------+

|    1 | [1,1,2]       |

|    2 | [1,null,null] |

|    3 | NULL          |

|    4 | [null]        |

+------+---------------+

Remove duplicate values from column c2.

mysql> select c1, array_distinct(c2) from test;

+------+----------------------+

| c1   | array_distinct(`c2`) |

+------+----------------------+

|    1 | [2,1]                |

|    2 | [null,1]             |

|    3 | NULL                 |

|    4 | [null]               |

+------+----------------------+