14.17. Array Functions and Operators
Subscript Operator: []
The [] operator is used to access an element of an array and is indexed starting from one:
SELECT my_array[1] AS first_element
Concatenation Operator: ||
The || operator is used to concatenate an array with an array or an element of the same type:
SELECT ARRAY [1] || ARRAY [2]; => [1, 2]
SELECT ARRAY [1] || 2; => [1, 2]
SELECT 2 || ARRAY [1]; => [2, 1]
Array Functions
- array_min(x) → x
- Returns the minimum value of input array. 
- array_max(x) → x
- Returns the maximum value of input array. 
- element_at(array<E>, index) → E
- Returns element of array at given index. If index >= 0, this function provides the same functionality as the SQL-standard subscript operator ([]). If index < 0, element_at accesses elements from the last to the first. 
- array_distinct(x) → array
- Remove duplicate values from the array x. 
- array_intersect(x, y) → array
- Returns an array of the elements in the intersection of x and y, without duplicates. 
- array_position(x, element) → bigint
- Returns the position of the first occurrence of the element in array x (or 0 if not found). 
- array_sort(x) → array
- Sorts and returns the array x. The elements of x must be orderable. 
- cardinality(x) → bigint
- Returns the cardinality (size) of the array x. 
- concat(x, y) → array
- Concatenates the arrays x and y. This function provides the same functionality as the SQL-standard concatenation operator (||). 
- contains(x, element) → boolean
- Returns true if the array x contains the element. 
- array_join(x, delimiter, null_replacement) → varchar
- Concatenates the elements of the given array using the delimiter and an optional string to replace nulls. 
- array_remove(x, element) → array
- Remove all elements that equal element from array x. 
- slice(x, start, length) → array
- Subsets array x starting from index start (or starting from the end if start is negative) with a length of length.