(PECL sphinx >= 0.1.0)
SphinxClient::setGroupBy — Set grouping attribute
$attribute
, int $func
[, string $groupsort = "@group desc"
] ) : boolSets grouping attribute, function, and group sorting mode, and enables grouping.
Grouping feature is very similar to GROUP BY clause in SQL. Results produced by this function call are going to be the same as produced by the following pseudo code: SELECT ... GROUP BY $func($attribute) ORDER BY $groupsort.
attributeA string containing group-by attribute name.
funcConstant, which sets a function applied to the attribute value in order to compute group-by key.
groupsortAn optional clause controlling how the groups are sorted.
成功时返回 TRUE， 或者在失败时返回 FALSE。