Returns an array of the children H3 cells of the input H3 cell at the specified resolution.
Requires: SQL warehouse version 2022.35 or higher. This version is available in the Preview channel.
h3CellIdExpr: A BIGINT expression, or a hexadecimal STRING expression representing an H3 cell ID.
resolutionExpr: An INT expression, whose value is expected to be between
15inclusive, specifying the resolution of the children H3 cell IDs.
An ARRAY of values of the same type as the type of the
h3CellIdExpr expression, corresponding to the children H3 cell IDs of the input H3 cell at the specified resolution.
The function returns NULL if any of the two input expressions is NULL.
The function does partial validation regarding whether the input argument is a valid H3 cell ID. A necessary, but not sufficient condition for a valid H3 ID is that its value is between
The behavior of the function is undefined if the input cell ID is not a valid cell ID.
If the value of the
resolutionExpr is equal to the resolution of the input H3 cell ID, the returned array contains a single value equal to the input H3 cell ID.
h3CellIdExpris a STRING that cannot be converted to a BIGINT or corresponds to a BIGINT value that is smaller than
0x08001fffffffffffor larger than
0x08ff3b6db6db6db6, the function returns H3_INVALID_CELL_ID.
resolutionExpris smaller than
h3_resolution(h3CellIdExpr)or larger than
15, the function returns H3_INVALID_RESOLUTION_VALUE.
-- Simple example taking a long as input. > SELECT h3_tochildren(599686042433355775, 6) [604189641121202175,604189641255419903,604189641389637631,604189641523855359,604189641658073087,604189641792290815,604189641926508543] -- Simple example taking a hexadecimal string as input. > SELECT h3_tochildren('85283473fffffff', 6) [862834707ffffff,86283470fffffff,862834717ffffff,86283471fffffff,862834727ffffff,86283472fffffff,862834737ffffff] -- First input is an invalid H3 cell ID. > SELECT h3_tochildren(0, 15) [H3_INVALID_CELL_ID] 0 is not a valid H3 cell ID -- Second input is an invalid resolution value. > SELECT h3_tochildren('85283473fffffff', 0) [H3_INVALID_RESOLUTION_VALUE] H3 resolution 0 must be between 5 and 15, inclusive