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Version: 2.5

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]               |

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