📅 最后修改于: 2020-12-25 05:05:16 🧑 作者: Mango
让我们看一下XQuery提供的常用序列函数列表：
| Index | Name | Description |
|---|---|---|
| 1) | count($seq as item()*) | It is used to count the items in a sequence. |
| 2) | sum($seq as item()*) | It is used to return the sum of the items in a sequence. |
| 3) | avg($seq as item()*) | It is used to return the average of the items in a sequence. |
| 4) | min($seq as item()*) | It is used to return the minimum valued item in a sequence. |
| 5) | max($seq as item()*) | It is used to return the maximum valued item in a sequence. |
| 6) | distinct-values($seq as item()*) | It returns select distinct items from a sequence. |
| 7) | subsequence($seq as item()*, $startingloc as xs:double, $length as xs:double) | It is used to return a subset of provided sequence. |
| 8) | insert-before($seq as item()*, $position as xs:integer, $inserts as item()*) | It is used to insert an item in a sequence. |
| 9) | remove($seq as item()*, $position as xs:integer) | It is used to remove an item from a sequence. |
| 10) | reverse($seq as item()*) | It is used to return the reversed sequence. |
| 11) | index-of($seq as anyatomictype()*, $target as anyatomictype()) | It returns indexes as integers to indicate availability of an item within a sequence. |
| 12) | last() | It returns the last element of a sequence when used in predicate expression. |
| 13) | position() | It is used in FLOWR expressions to get the position of an item in a sequence. |