plpgsql 数组相关

Posted 2020-10-03 物来顺心,事去宁心!

Function	Return Type	Description	Example	Result
array_append(anyarray,anyelement)	anyarray	append an element to the end of an array	array_append(ARRAY[1,2], 3)	{1,2,3}
array_cat(anyarray,anyarray)	anyarray	concatenate two arrays	array_cat(ARRAY[1,2,3], ARRAY[4,5])	{1,2,3,4,5}
array_ndims(anyarray)	int	returns the number of dimensions of the array	array_ndims(ARRAY[[1,2,3], [4,5,6]])	2
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_fill(anyelement,int[], [, int[]])	anyarray	returns an array initialized with supplied value and dimensions, optionally with lower bounds other than 1	array_fill(7, ARRAY[3], ARRAY[2])	[2:4]={7,7,7}
array_length(anyarray,int)	int	returns the length of the requested array dimension	array_length(array[1,2,3], 1)	3
array_lower(anyarray,int)	int	returns lower bound of the requested array dimension	array_lower(‘[0:2]={1,2,3}‘::int[], 1)	0
array_position(anyarray,anyelement [, int])	int	returns the subscript of the first occurrence of the second argument in the array, starting at the element indicated by the third argument or at the first element (array must be one-dimensional)	array_position(ARRAY[‘sun‘,‘mon‘,‘tue‘,‘wed‘,‘thu‘,‘fri‘,‘sat‘], ‘mon‘)	2
array_positions(anyarray,anyelement)	int[]	returns an array of subscripts of all occurrences of the second argument in the array given as first argument (array must be one-dimensional)	array_positions(ARRAY[‘A‘,‘A‘,‘B‘,‘A‘], ‘A‘)	{1,2,4}
array_prepend(anyelement,anyarray)	anyarray	append an element to the beginning of an array	array_prepend(1, ARRAY[2,3])	{1,2,3}
array_remove(anyarray,anyelement)	anyarray	remove all elements equal to the given value from the array (array must be one-dimensional)	array_remove(ARRAY[1,2,3,2], 2)	{1,3}
array_replace(anyarray,anyelement, anyelement)	anyarray	replace each array element equal to the given value with a new value	array_replace(ARRAY[1,2,5,4], 5, 3)	{1,2,3,4}
array_to_string(anyarray,text [, text])	text	concatenates array elements using supplied delimiter and optional null string	array_to_string(ARRAY[1, 2, 3, NULL, 5], ‘,‘, ‘*‘)	1,2,3,*,5
array_upper(anyarray,int)	int	returns upper bound of the requested array dimension	array_upper(ARRAY[1,8,3,7], 1)	4
cardinality(anyarray)	int	returns the total number of elements in the array, or 0 if the array is empty	cardinality(ARRAY[[1,2],[3,4]])	4
string_to_array(text,text [, text])	text[]	splits string into array elements using supplied delimiter and optional null string	string_to_array(‘xx~^~yy~^~zz‘, ‘~^~‘, ‘yy‘)	{xx,NULL,zz}
unnest(anyarray)	setof anyelement	expand an array to a set of rows	unnest(ARRAY[1,2])	1 2 (2 rows)
unnest(anyarray, anyarray[, ...])	setof anyelement, anyelement [, ...]	expand multiple arrays (possibly of different types) to a set of rows. This is only allowed in the FROM clause; see Section 7.2.1.4	unnest(ARRAY[1,2],ARRAY[‘foo‘,‘bar‘,‘baz‘])	1 foo 2 bar NULL baz (3 rows)