add-example-for-getting-vertex/edge-without-specifying-tag/edge-type (#…

…1773)

* add-example-for-getting-vertex/edge-without-specifying-tag/edge-type

* Update 2.match.md

docs-2.0/2.quick-start/6.cheatsheet-for-ngql.md

@@ -185,14 +185,14 @@
   | Match vertices                      | `(v)`                                                        | You can use a user-defined variable in a pair of parentheses to represent a vertex in a pattern. For example: `(v)`. |
   | Match tags                     | `MATCH (v:player) RETURN v`                                  | You can specify a tag with `:<tag_name>` after the vertex in a pattern.           |
   | Match multiple tags | `MATCH (v:player:team) RETURN v LIMIT 10` | To match vertices with multiple tags, use colons (:). |
-  | Match vertex properties                | `MATCH (v:player{name:"Tim Duncan"}) RETURN v`               | You can specify a vertex property with `{<prop_name>: <prop_value>}` after the tag in a pattern. |
+  | Match vertex properties                | `MATCH (v:player{name:"Tim Duncan"}) RETURN v`  <br><br>`MATCH (v) WITH v, properties(v) as props, keys(properties(v)) as kk LIMIT 10000 WHERE [i in kk where props[i] == "Tim Duncan"] RETURN v`             | You can specify a vertex property with `{<prop_name>: <prop_value>}` after the tag in a pattern; or use a vertex property value to get vertices directly. |
   | Match a VID.                  | `MATCH (v) WHERE id(v) == 'player101' RETURN v`              | You can use the VID to match a vertex. The `id()` function can retrieve the VID of a vertex.         |
   | Match multiple VIDs.                  | `MATCH (v:player { name: 'Tim Duncan' })--(v2) WHERE id(v2) IN ["player101", "player102"] RETURN v2` | To match multiple VIDs, use `WHERE id(v) IN [vid_list]`.        |
   | Match connected vertices                | `MATCH (v:player{name:"Tim Duncan"})--(v2) RETURN v2.player.name AS Name` | You can use the `--` symbol to represent edges of both directions and match vertices connected by these edges. You can add a `>` or `<` to the `--` symbol to specify the direction of an edge. |
   | Match paths                    | `MATCH p=(v:player{name:"Tim Duncan"})-->(v2) RETURN p`      | Connected vertices and edges form a path. You can use a user-defined variable to name a path as follows. |
   | Match edges                      | `MATCH (v:player{name:"Tim Duncan"})-[e]-(v2) RETURN e`<br>`MATCH ()<-[e]-() RETURN e LIMIT 3`      | Besides using `--`, `-->`, or `<--` to indicate a nameless edge, you can use a user-defined variable in a pair of square brackets to represent a named edge. For example: `-[e]-`. |
   | Match an edge type              | `MATCH ()-[e:follow]-() RETURN e LIMIT 5`                            |Just like vertices, you can specify an edge type with `:<edge_type>` in a pattern. For example: `-[e:follow]-`. |
-  | Match edge type properties                | ` MATCH (v:player{name:"Tim Duncan"})-[e:follow{degree:95}]->(v2) RETURN e` | You can specify edge type properties with `{<prop_name>: <prop_value>}` in a pattern. For example: `[e:follow{likeness:95}]`. |
+  | Match edge type properties                | ` MATCH (v:player{name:"Tim Duncan"})-[e:follow{degree:95}]->(v2) RETURN e` <br><br>`MATCH ()-[e]->() WITH e, properties(e) as props, keys(properties(e)) as kk LIMIT 10000 WHERE [i in kk where props[i] == 90] RETURN e`| You can specify edge type properties with `{<prop_name>: <prop_value>}` in a pattern. For example: `[e:follow{likeness:95}]`; or use an edge type property value to get edges directly. |
   | Match multiple edge types           | `MATCH (v:player{name:"Tim Duncan"})-[e:follow | :serve]->(v2) RETURN e` | The `|` symbol can help matching multiple edge types. For example: `[e:follow|:serve]`. The English colon (:) before the first edge type cannot be omitted, but the English colon before the subsequent edge type can be omitted, such as `[e:follow|serve]`. |
   | Match multiple edges                  | `MATCH (v:player{name:"Tim Duncan"})-[]->(v2)<-[e:serve]-(v3) RETURN v2, v3` | You can extend a pattern to match multiple edges in a path.                       |
   | Match fixed-length paths               | `MATCH p=(v:player{name:"Tim Duncan"})-[e:follow*2]->(v2) RETURN DISTINCT v2 AS Friends` | You can use the `:<edge_type>*<hop>` pattern to match a fixed-length path. `hop` must be a non-negative integer. The data type of `e` is the list.|

docs-2.0/3.ngql-guide/7.general-query-statements/2.match.md

@@ -195,6 +195,21 @@ nebula> MATCH (v:player) \
 
     In openCypher 9, `=` is the equality operator. However, in nGQL, `==` is the equality operator and `=` is the assignment operator (as in C++ or Java).
 
+
+You also use properties without specifying a tag to get vertices directly. For example, to get all the vertices with the vertex property value Tim Duncan.
+
+```ngql
+nebula> MATCH (v) \
+        WITH v, properties(v) as props, keys(properties(v)) as kk \
+        LIMIT 10000 WHERE [i in kk where props[i] == "Tim Duncan"] \
+        RETURN v;
++----------------------------------------------------+
+| v                                                  |
++----------------------------------------------------+
+| ("player100" :player{age: 42, name: "Tim Duncan"}) |
++----------------------------------------------------+
+```
+
 ### Match VIDs
 
 You can use the VID to match a vertex. The `id()` function can retrieve the VID of a vertex.
@@ -399,6 +414,25 @@ nebula> MATCH (v:player{name:"Tim Duncan"})-[e:follow{degree:95}]->(v2) \
 +--------------------------------------------------------+
 ```
 
+
+You also use properties without specifying an edge type to get edges directly. For example, to get all the edges with the edge property value 90.
+
+```ngql
+nebula> MATCH ()-[e]->() \
+        WITH e, properties(e) as props, keys(properties(e)) as kk \
+        LIMIT 10000 WHERE [i in kk where props[i] == 90] \
+        RETURN e;
++----------------------------------------------------+
+| e                                                  |
++----------------------------------------------------+
+| [:follow "player125"->"player100" @0 {degree: 90}] |
+| [:follow "player140"->"player114" @0 {degree: 90}] |
+| [:follow "player133"->"player144" @0 {degree: 90}] |
+| [:follow "player133"->"player114" @0 {degree: 90}] |
+...
++----------------------------------------------------+
+```
+
 ### Match multiple edge types
 
 The `|` symbol can help matching multiple edge types. For example: `[e:follow|:serve]`. The English colon (:) before the first edge type cannot be omitted, but the English colon before the subsequent edge type can be omitted, such as `[e:follow|serve]`.