Add docs for OR label expressions

pages/querying/clauses/match.mdx

@@ -12,6 +12,8 @@ The `MATCH` clause is used to obtain data from the database by matching it to a
 1. [Matching nodes](#1-matching-nodes) <br />
     1.1. [Get all nodes](#11-get-all-nodes) <br />
     1.2. [Get all nodes with a label](#12-get-all-nodes-with-a-label) <br />
+    1.3. [Get nodes with with all of multiple labels](#13-get-nodes-with-all-labels) <br />
+    1.4. [Get nodes with any of multiple labels](#14-get-nodes-with-any-labels) <br />
 2. [Matching relationships](#2-matching-relationships) <br />
     2.1. [Get all related nodes](#21-get-all-related-nodes) <br />
     2.2. [Get related nodes with a label](#22-get-related-nodes-with-a-label) <br />
@@ -37,12 +39,13 @@ Return it with the [`id()` function](/querying/functions).
 
 </Callout>
 
-## Data Set
+## Dataset
 
-The following examples are executed with this data set. You can create this data set 
-locally by executing the queries at the end of the page: [Dataset queries](#dataset-queries).
+The following examples are executed with this dataset. You can replicate this
+dataset locally by executing the queries at the end of the page: [Dataset
+queries](#dataset-queries).
 
-![Data set](/pages/querying/clauses/data_set.png)
+![Schema](/pages/querying/clauses/graph_schema.png)
 
 ## 1. Matching nodes
 
@@ -63,9 +66,11 @@ Output:
 | (:Country {continent: "Europe", language: "German", name: "Germany", population: 83000000})         |
 | (:Country {continent: "Europe", language: "French", name: "France", population: 67000000})          |
 | (:Country {continent: "Europe", language: "English", name: "United Kingdom", population: 66000000}) |
-| (:Person {name: "John"})                                                                            |
+| (:Person:Employee {name: "John"})                                                                   |
 | (:Person {name: "Harry"})                                                                           |
 | (:Person {name: "Anna"})                                                                            |
+| (:City {name: "Berlin", population: 3600000})                                                       |
+| (:City {name: "Paris", population: 2140000})                                                        |
 +-----------------------------------------------------------------------------------------------------+
 ```
 
@@ -89,6 +94,58 @@ Output:
 +-----------------------------------------------------------------------------------------------------+
 ```
 
+### 1.3. Get nodes with all labels
+
+If you want to match nodes that have **both** labels (e.g. `:Person` and
+`:Employee`), you can use a chained label. This only returns nodes that have
+both `Person` and `Employee` labels.
+
+```cypher
+MATCH (n:Person:Employee)
+RETURN n;
+```
+
+Output:
+```nocopy
++-----------------------------------+
+| n                                 |
++-----------------------------------+
+| (:Person:Employee {name: "John"}) |
++-----------------------------------+
+```
+
+### 1.4. Get nodes with any of labels
+
+You can use the `OR` (`|`) operator to match nodes that have **any** of the
+specified labels:
+
+```cypher
+MATCH (n:Country|Person)
+RETURN n;
+```
+
+Output:
+```nocopy
++-----------------------------------------------------------------------------------------------------+
+| n                                                                                                   |
++-----------------------------------------------------------------------------------------------------+
+| (:Country {continent: "Europe", language: "German", name: "Germany", population: 83000000})         |
+| (:Country {continent: "Europe", language: "French", name: "France", population: 67000000})          |
+| (:Country {continent: "Europe", language: "English", name: "United Kingdom", population: 66000000}) |
+| (:Person:Employee {name: "John"})                                                                           |
+| (:Person {name: "Harry"})                                                                           |
+| (:Person {name: "Anna"})                                                                            |
++-----------------------------------------------------------------------------------------------------+
+```
+
+This allows you to retrieve nodes of different types in a single query, making label-based exploration more flexible.
+
+<Callout type="info">
+
+Label OR expressions (`|`) can't be used in `MERGE` or `CREATE` clauses.
+
+</Callout>
+
 ## 2. Matching relationships
 
 ### 2.1. Get all related nodes
@@ -145,11 +202,11 @@ RETURN p;
 
 Output:
 ```nocopy
-+--------------------------+
-| p                        |
-+--------------------------+
-| (:Person {name: "John"}) |
-+--------------------------+
++-----------------------------------+
+| p                                 |
++-----------------------------------+
+| (:Person:Employee {name: "John"}) |
++-----------------------------------+
 ```
 
 ### 2.4. Get a relationship
@@ -275,13 +332,12 @@ RETURN n;
 
 Output:
 ```nocopy
-+---------------------------------------------------------------------------------------------+
-| n                                                                                           |
-+---------------------------------------------------------------------------------------------+
-| (:Person {name: "Harry"})                                                                   |
-| (:Person {name: "Anna"})                                                                    |
-| (:Country {continent: "Europe", language: "German", name: "Germany", population: 83000000}) |
-+---------------------------------------------------------------------------------------------+
++---------------------------+
+| n                         |
++---------------------------+
+| (:Person {name: "Harry"}) |
+| (:Person {name: "Anna"})  |
++---------------------------+
 ```
 
 ### 3.2. Variable length relationships with multiple relationship types
@@ -295,13 +351,13 @@ RETURN p;
 
 Output:
 ```nocopy
-+---------------------------+
-| p                         |
-+---------------------------+
-| (:Person {name: "John"})  |
-| (:Person {name: "Harry"}) |
-| (:Person {name: "Anna"})  |
-+---------------------------+
++-----------------------------------+
+| p                                 |
++-----------------------------------+
+| (:Person {name: "Harry"})         |
+| (:Person:Employee {name: "John"}) |
+| (:Person {name: "Anna"})          |
++-----------------------------------+
 ```
 
 ### 3.3. Returning multiple relationships with variable length
@@ -396,13 +452,7 @@ RETURN names;
 
 Output:
 
-```nocopy
-+-------+
-| names |
-+-------+
-| Null  |
-+-------+
-```
+`Empty set`
 
 Since the dataset doesn't contain any nodes labeled as `Country` with a property `continent` with the value `Asia`, the second `MATCH` clause returns an empty dataset and therefore the output is also an empty list. To avoid getting an empty list as an output, due to any of the `MATCH` clauses returning an empty set, use `OPTIONAL MATCH` clause: 
 
@@ -426,7 +476,7 @@ Output:
 
 The `OPTIONAL MATCH` clause bypasses the empty set and the query returns only non-empty sets. Therefore, the output of the query is a list containing only the results of the first `MATCH` clause.    
 
-## Dataset Queries
+## Dataset queries
 
 We encourage you to try out the examples by yourself.
 You can get our data set locally by executing the following query block.
@@ -440,7 +490,7 @@ CREATE (c3:Country {name: 'United Kingdom', language: 'English', continent: 'Eur
 
 MATCH (c1),(c2)
 WHERE c1.name = 'Germany' AND c2.name = 'France'
-CREATE (c2)<-[:WORKING_IN {date_of_start: 2014}]-(p:Person {name: 'John'})-[:LIVING_IN {date_of_start: 2014}]->(c1);
+CREATE (c2)<-[:WORKING_IN {date_of_start: 2014}]-(p:Person:Employee {name: 'John'})-[:LIVING_IN {date_of_start: 2014}]->(c1);
 
 MATCH (c)
 WHERE c.name = 'United Kingdom'
@@ -458,5 +508,14 @@ MATCH (p),(c1),(c2)
 WHERE p.name = 'Anna' AND c1.name = 'United Kingdom' AND c2.name = 'Germany'
 CREATE (c2)<-[:LIVING_IN {date_of_start: 2014}]-(p)-[:LIVING_IN {date_of_start: 2014}]->(c1);
 
+CREATE (city1:City {name: 'Berlin', population: 3600000});
+CREATE (city2:City {name: 'Paris', population: 2140000});
+
+MATCH (city1:City {name: 'Berlin'}), (country1:Country {name: 'Germany'})
+CREATE (city1)-[:LOCATED_IN]->(country1);
+
+MATCH (city2:City {name: 'Paris'}), (country2:Country {name: 'France'})
+CREATE (city2)-[:LOCATED_IN]->(country2);
+
 MATCH (n)-[r]->(m) RETURN n,r,m;
 ```

pages/querying/differences-in-cypher-implementations.mdx

@@ -190,8 +190,6 @@ using `OPTIONAL` expansions, function calls, etc.
 - Numerical:
   - An octal `INTEGER` literal (starting with `0o`): `0o1372`, `0o5671`
   - A `FLOAT` literal: `Inf`, `Infinity`, `NaN`
-- Boolean:
-  - Label expressions: `(n:A|B)` -> Track progress on [GitHub](https://github.com/memgraph/memgraph/issues/1848) and add a comment if you require such a feature.
 
 {<h4 className="custom-header">Conditional expressions (<code>CASE</code>)</h4>}
 - More than one value after `WHEN` operator: