From d2252ab5c6e6c48e39a9515d5043ade63900b586 Mon Sep 17 00:00:00 2001
From: "abby.huang" <78209557+abby-cyber@users.noreply.github.com>
Date: Mon, 30 Jan 2023 15:30:31 +0800
Subject: [PATCH] Optional match does not support where clauses  (#2515)

* Optional match does not support where clauses

* Update 6.cheatsheet-for-ngql-command.md

* desc updates
---
 .../6.cheatsheet-for-ngql-command.md          |  2 +-
 .../optional-match.md                         | 19 ++++++++++++++++---
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/docs-2.0/2.quick-start/6.cheatsheet-for-ngql-command.md b/docs-2.0/2.quick-start/6.cheatsheet-for-ngql-command.md
index f88544a6598..5b48a2c7c2a 100644
--- a/docs-2.0/2.quick-start/6.cheatsheet-for-ngql-command.md
+++ b/docs-2.0/2.quick-start/6.cheatsheet-for-ngql-command.md
@@ -214,7 +214,7 @@
 
     | 模式                | 示例                                                         | 说明                                           |
   | ------------------- | ------------------------------------------------------------ | ---------------------------------------------- |
-  |作为MATCH语句的可选项去匹配图数据库中的模式  | `MATCH (m)-[]->(n) WHERE id(m)=="player100" OPTIONAL MATCH (n)-[]->(l) WHERE id(n)=="player125" RETURN id(m),id(n),id(l)` | 如果图数据库中没有对应的模式，对应的列返回NULL。|
+  |作为`MATCH`语句的可选项去匹配图数据库中的模式  | `MATCH (m)-[]->(n) WHERE id(m)=="player100" OPTIONAL MATCH (n)-[]->(l) RETURN id(m),id(n),id(l)` | 如果图数据库中没有对应的模式，对应的列返回`NULL`。|
 
 * [LOOKUP](../3.ngql-guide/7.general-query-statements/5.lookup.md)
 
diff --git a/docs-2.0/3.ngql-guide/7.general-query-statements/optional-match.md b/docs-2.0/3.ngql-guide/7.general-query-statements/optional-match.md
index e25925621e4..48d03858b83 100644
--- a/docs-2.0/3.ngql-guide/7.general-query-statements/optional-match.md
+++ b/docs-2.0/3.ngql-guide/7.general-query-statements/optional-match.md
@@ -10,19 +10,27 @@
 
 本文操作仅适用于 nGQL 中的 openCypher 方式。
 
+## 使用限制
+
+`OPTIONAL MATCH`子句中暂不支持使用`WHERE`子句。
+
 ## 示例
 
 `MATCH`语句中使用`OPTIONAL MATCH`的示例如下：
 
 ```ngql
 nebula> MATCH (m)-[]->(n) WHERE id(m)=="player100" \
-        OPTIONAL MATCH (n)-[]->(l) WHERE id(n)=="player125" \
+        OPTIONAL MATCH (n)-[]->(l) \
         RETURN id(m),id(n),id(l);
 +-------------+-------------+-------------+
 | id(m)       | id(n)       | id(l)       |
 +-------------+-------------+-------------+
 | "player100" | "team204"   | __NULL__    |
-| "player100" | "player101" | __NULL__    |
+| "player100" | "player101" | "team204"   |
+| "player100" | "player101" | "team215"   |
+| "player100" | "player101" | "player100" |
+| "player100" | "player101" | "player102" |
+| "player100" | "player101" | "player125" |
 | "player100" | "player125" | "team204"   |
 | "player100" | "player125" | "player100" |
 +-------------+-------------+-------------+
@@ -32,11 +40,16 @@ nebula> MATCH (m)-[]->(n) WHERE id(m)=="player100" \
 
 ```ngql
 nebula> MATCH (m)-[]->(n) WHERE id(m)=="player100" \
-        MATCH (n)-[]->(l) WHERE id(n)=="player125" \
+        MATCH (n)-[]->(l) \
         RETURN id(m),id(n),id(l);
 +-------------+-------------+-------------+
 | id(m)       | id(n)       | id(l)       |
 +-------------+-------------+-------------+
+| "player100" | "player101" | "team204"   |
+| "player100" | "player101" | "team215"   |
+| "player100" | "player101" | "player100" |
+| "player100" | "player101" | "player102" |
+| "player100" | "player101" | "player125" |
 | "player100" | "player125" | "team204"   |
 | "player100" | "player125" | "player100" |
 +-------------+-------------+-------------+