fix coalesce() (#1860)

vesoft-inc · Jun 9, 2022 · a107c73 · a107c73
1 parent c946e27
commit a107c73
Showing 1 changed file with 7 additions and 7 deletions.
diff --git a/docs-2.0/3.ngql-guide/6.functions-and-expressions/6.list.md b/docs-2.0/3.ngql-guide/6.functions-and-expressions/6.list.md
@@ -13,7 +13,7 @@ Nebula Graph 支持以下列表（List）函数。
 | tail(list) | 返回不包含原列表第一个元素的新列表。|
 | head(list) | 返回列表的第一个元素。 |
 | last(list) | 返回列表的最后一个元素。 |
-| coalesce(list) | 返回列表中第一个非空元素。 |
+| coalesce(item0 [, item1, item2]) | 返回多个参数中第一个非空元素。 |
 | reduce() | 请参见 [reduce 函数](./11.reduce.md)。 |
 
 !!! Note
@@ -24,12 +24,12 @@ Nebula Graph 支持以下列表（List）函数。
 
 ```ngql
 nebula> WITH [NULL, 4923, 'abc', 521, 487] AS ids \
-        RETURN reverse(ids), tail(ids), head(ids), last(ids), coalesce(ids);
-+-----------------------------------+-------------------------+-----------+-----------+---------------+
-| reverse(ids)                      | tail(ids)               | head(ids) | last(ids) | coalesce(ids) |
-+-----------------------------------+-------------------------+-----------+-----------+---------------+
-| [487, 521, "abc", 4923, __NULL__] | [4923, "abc", 521, 487] | __NULL__  | 487       | 4923          |
-+-----------------------------------+-------------------------+-----------+-----------+---------------+
+        RETURN reverse(ids), tail(ids), head(ids), last(ids), coalesce(ids[0], ids[1], ids[2]), head([x IN ids WHERE x IS NOT NULL | x]);
++-----------------------------------+-------------------------+-----------+-----------+--------------------------------+--------------------------------------------------------------+
+| reverse(ids)                      | tail(ids)               | head(ids) | last(ids) | coalesce(ids[0],ids[1],ids[2]) | head([__VAR_0 IN ids WHERE $__VAR_0 IS NOT NULL | $__VAR_0]) |
++-----------------------------------+-------------------------+-----------+-----------+--------------------------------+--------------------------------------------------------------+
+| [487, 521, "abc", 4923, __NULL__] | [4923, "abc", 521, 487] | __NULL__  | 487       | 4923                           | 4923                                                         |
++-----------------------------------+-------------------------+-----------+-----------+--------------------------------+--------------------------------------------------------------+
 
 nebula> MATCH (a:player)-[r]->() \
         WHERE id(a) == "player100" \