9.14. Array Functions and Operators

Table 9.35, “array Operators” shows the operators available for array types.

Table 9.35. array Operators

Operator Description Example Result
= equal ARRAY[1.1,2.1,3.1]::int[] = ARRAY[1,2,3] t
<> not equal ARRAY[1,2,3] <> ARRAY[1,2,4] t
< less than ARRAY[1,2,3] < ARRAY[1,2,4] t
> greater than ARRAY[1,4,3] > ARRAY[1,2,4] t
<= less than or equal ARRAY[1,2,3] <= ARRAY[1,2,3] t
>= greater than or equal ARRAY[1,4,3] >= ARRAY[1,4,3] t
|| array-to-array concatenation ARRAY[1,2,3] || ARRAY[4,5,6] {1,2,3,4,5,6}
|| array-to-array concatenation ARRAY[1,2,3] || ARRAY[[4,5,6],[7,8,9]] {{1,2,3},{4,5,6},{7,8,9}}
|| element-to-array concatenation 3 || ARRAY[4,5,6] {3,4,5,6}
|| array-to-element concatenation ARRAY[4,5,6] || 7 {4,5,6,7}

See Section 8.10, “Arrays” for more details about array operator behavior.

Table 9.36, “array Functions” shows the functions available for use with array types. See Section 8.10, “Arrays” for more discussion and examples of the use of these functions.

Table 9.36. array Functions

Function Return Type Description Example Result
array_cat (anyarray, anyarray) anyarray concatenate two arrays array_cat(ARRAY[1,2,3], ARRAY[4,5]) {1,2,3,4,5}
array_append (anyarray, anyelement) anyarray append an element to the end of an array array_append(ARRAY[1,2], 3) {1,2,3}
array_prepend (anyelement, anyarray) anyarray append an element to the beginning of an array array_prepend(1, ARRAY[2,3]) {1,2,3}
array_dims (anyarray) text returns a text representation of array's dimensions array_dims(array[[1,2,3], [4,5,6]]) [1:2][1:3]
array_lower (anyarray, integer) integer returns lower bound of the requested array dimension array_lower(array_prepend(0, ARRAY[1,2,3]), 1) 0
array_upper (anyarray, integer) integer returns upper bound of the requested array dimension array_upper(ARRAY[1,2,3,4], 1) 4
array_to_string (anyarray, text) text concatenates array elements using provided delimiter array_to_string(array[1, 2, 3], '~^~') 1~^~2~^~3
string_to_array (text, text) text[] splits string into array elements using provided delimiter string_to_array( 'xx~^~yy~^~zz', '~^~') {xx,yy,zz}