Table 9-41 shows the operators available for array types.
Table 9-41. 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 for more details about array operator behavior.
Table 9-42 shows the functions available for use with array types. See Section 8.10 for more discussion and examples for the use of these functions.
Table 9-42. 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}
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