Calculates the union of Array a and Array b, and removes duplicate elements.
Syntax
array<T> array_union(array<T> <a>, array<T> <b>)Parameters
a and b: required. This parameter specifies an array. that T in array<T> specifies the data type of the elements in the arrays. The elements can be of any data type. The elements in Array a and the elements in Array b must be of the same data type.
The following data types are supported:
TINYINT, SMALLINT, INT, and BIGINT
FLOAT and DOUBLE
BOOLEAN
DECIMAL and DECIMALVAL
DATE, DATETIME, TIMESTAMP, IntervalDayTime, and IntervalYearMonth
STRING, BINARY, VARCHAR, and CHAR
ARRAY, STRUCT, and MAP
Return value
A value of the ARRAY type is returned. If Array a or Array b is null, null is returned.
Examples
Example 1: Calculate the union of
array(1, 2, 3)andarray(1, 3, 5), and remove duplicate elements. Sample statement:-- The return value is [1,2,3,5]. select array_union(array(1, 2, 3), array(1, 3, 5));Example 2: Calculate the union of two arrays and remove duplicate elements. One of the arrays is null. Sample statement:
-- The return value is null. select array_union(array(1, 2, 3), null);
Related functions
ARRAY_UNION is a complex type function. For more information about the functions that are used to process data of complex data types, such as ARRAY, MAP, STRUCT, and JSON, see Complex type functions.