Generates an array of all unique elements among one or more arrays.

- Inputs are column names or array literals.
- If an element appears twice in one or more arrays, it is listed once in the output array.

**Wrangle vs. SQL:** This function is part of Wrangle
, a proprietary data transformation language. Wrangle
is not SQL. For more information, see Wrangle Language.

## Basic Usage

**Array literal reference example:**

arrayunique([["A","B"],["A","C"]])

**Output:** Returns a single array:

["A","B","C"]

**Single-column reference example:**

arrayunique([array1])

**Output:** Returns a single array of all unique elements in `array1`

.

**Multi-column reference example:**

arrayunique([array1,array2])

**Output:** Returns a single array listing all unique elements in `array1`

and `array2`

.

## Syntax and Arguments

arrayunique(array_ref1,array_ref2)

Argument | Required? | Data Type | Description |
---|---|---|---|

array_ref1 | Y | string or array | Name of first column or first array literal to apply to the function |

array_ref2 | N | string or array | Name of second column or second array literal to apply to the function |

For more information on syntax standards, see Language Documentation Syntax Notes.

### array_ref1, array_ref2

Array literals or names of the array columns whose unique elements you want to derive.

**Usage Notes:**

Required? | Data Type | Example Value |
---|---|---|

Yes (at least one) | Array literal or column reference | `myArray1` , `myArray2` |

## Examples

**Tip:** For additional examples, see Common Tasks.

### Example - Simple unique example

**Functions**:

Item | Description |
---|---|

ARRAYCONCAT Function | Combines the elements of one array with another, listing all elements of the first array before listing all elements of the second array. |

ARRAYINTERSECT Function | Generates an array containing all elements that appear in multiple input arrays, referenced as column names or array literals. |

ARRAYCROSS Function | Generates a nested array containing the cross-product of all elements in two or more arrays. |

ARRAYUNIQUE Function | Generates an array of all unique elements among one or more arrays. |

**Source:**

Code formatting has been applied to improve legibility.

Item | ArrayA | ArrayB |
---|---|---|

Item1 | `["A","B","C"]` | `["1","2","3"]` |

Item2 | `["A","B"]` | `["A","B","C"]` |

Item3 | `["D","E","F"]` | `["4","5","6"]` |

**Transformation:**

You can apply the following transforms in the following order. Note that the column names must be different from the transform name, which is a reserved word.

Transformation Name | `New formula` |
---|---|

Parameter: Formula type | `Single row formula` |

Parameter: Formula | `ARRAYCONCAT([Letters,Numerals])` |

Parameter: New column name | `'concat2'` |

Transformation Name | `New formula` |
---|---|

Parameter: Formula type | `Single row formula` |

Parameter: Formula | `ARRAYINTERSECT([Letters,Numerals])` |

Parameter: New column name | `'intersection2'` |

Transformation Name | `New formula` |
---|---|

Parameter: Formula type | `Single row formula` |

Parameter: Formula | `ARRAYCROSS([Letters,Numerals])` |

Parameter: New column name | `'cross2'` |

Transformation Name | `New formula` |
---|---|

Parameter: Formula type | `Single row formula` |

Parameter: Formula | `ARRAYUNIQUE([Letters,Numerals])` |

Parameter: New column name | `'unique2'` |

**Results:**

For display purposes, the results table has been broken down into three separate sets of columns.

Column set 1:

Item | ArrayA | ArrayB | concat2 | intersection2 |
---|---|---|---|---|

Item1 |
| `["1","2","3"]` | `["A","B","C","1","2","3"]` | `[ ]` |

Item2 | `["A","B"]` | `["A","B","C"]` | `["A","B","A","B","C"]` | `["A","B"]` |

Item3 | `["D","E","F"]` | `["4","5","6"]` | `["D","E","F","4","5","6"]` | `[ ]` |

Column set 2:

Item | cross2 |
---|---|

Item1 | `[["A","1"],["A","2"],["A","3"],["B","1"],["B","2"],["B","3"],["C","1"],["C","2"],["C","3"]]` |

Item2 | `[["A","A"],["A","B"],["A","C"],["B","A"],["B","B"],["B","C"]]` |

Item3 | ```
[["D","4"],["D","5"],["D","6"],["E","4"],["E","5"],["E","6"],
["F","4"],["F","5"],["F","6"]]
``` |

Column set 3:

Item | unique2 |
---|---|

Item1 | `["A","B","C","1","2","3"]` |

Item2 | `["A","B","C"]` |

Item3 | ```
["D","E","F","4","5","6"]
``` |

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