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 for the use of these functions.
Table 9.36. array Functions
Function | Return Type | Description | Example | Result |
---|---|---|---|---|
array_cat (anyarray, anyarray) | anyarray | concatenate two arrays, returning NULL for NULL inputs | 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, returning NULL for NULL inputs | array_append(ARRAY[1,2], 3) | {1,2,3} |
array_prepend (anyelement, anyarray) | anyarray | append an element to the beginning of an array, returning NULL for NULL inputs | array_prepend(1, ARRAY[2,3]) | {1,2,3} |
array_dims (anyarray) | text | returns a text representation of array dimension lower and upper bounds, generating an ERROR for NULL inputs | 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, returning NULL for NULL inputs | array_lower(array_prepend(0, ARRAY[1,2,3]), 1) | 0 |
array_upper (anyarray, integer) | integer | returns upper bound of the requested array dimension, returning NULL for NULL inputs | array_upper(ARRAY[1,2,3,4], 1) | 4 |
array_to_string (anyarray, text) | text | concatenates array elements using provided delimiter, returning NULL for NULL inputs | array_to_string(array[1, 2, 3], '~^~') | 1~^~2~^~3 |
string_to_array (text, text) | text[] | splits string into array elements using provided delimiter, returning NULL for NULL inputs | string_to_array( 'xx~^~yy~^~zz', '~^~') | {xx,yy,zz} |