Add a chapter in user documentation on data types

Reviewers: florijan, buda

Reviewed By: florijan

Subscribers: pullbot

Differential Revision: https://phabricator.memgraph.io/D564

docs/user_technical/README.md

@@ -11,6 +11,7 @@ data structures, multi-version concurrency control and asynchronous IO.
   * [About Memgraph](#about-memgraph)
   * [Installation](installation.md)
   * [Quick Start](quick-start.md)
+  * [Storable Data Types](data-types.md)
   * [openCypher Query Language](open-cypher.md)
   * [Upcoming Features](upcoming-features.md)
 

docs/user_technical/data-types.md

@@ -0,0 +1,36 @@
+## Storable Data Types
+
+Since *Memgraph* is a *graph* database management system, data is stored in
+the form of graph elements: nodes and edges. Each graph element can also
+contain various types of data. This chapter describes which data types are
+supported in *Memgraph*.
+
+### Node Labels & Edge Types
+
+Each node can have any number of labels. A label is a text value, which can be
+used to *label* or group nodes according to users' desires. A user can change
+labels at any time. Similarly to labels, each edge can have a type,
+represented as text. Unlike nodes, which can have multiple labels or none at
+all, edges *must* have exactly one edge type. Another difference to labels, is
+that the edge types are set upon creation and never modified again.
+
+### Properties
+
+Nodes and edges can store various properties. These are like mappings or
+tables containing property names and their accompanying values. Property names
+are represented as text, while values can be of different types. Each property
+name can store a single value, it is not possible to have multiple properties
+with the same name on a single graph element. Naturally, the same property
+names can be found across multiple graph elements. Also, there are no
+restrictions on the number of properties that can be stored in a single graph
+element. The only restriction is that the values must be of the supported
+types. Following is a table of supported data types.
+
+ Type      | Description
+-----------|------------
+ `Null`    | Denotes that the property has no value. This is the same as if the property does not exist.
+ `String`  | A character string, i.e. text.
+ `Boolean` | A Boolean value, either `true` or `false`.
+ `Integer` | An integer number.
+ `Float`   | A floating-point number, i.e. a real number.
+ `List`    | A list containing any number of property values of any supported type. It can be used to store multiple values under a single property name.

docs/user_technical/open-cypher.md

@@ -8,13 +8,13 @@ providing a powerful interface for working with graph based data.
 chapter contains the details of features which are implemented. Additionally,
 not yet supported features of the language are listed.
 
-  * [Reading existing Data](#reading-existing-data)
-  * [Writing new Data](#writing-new-data)
+  * [Reading Existing Data](#reading-existing-data)
+  * [Writing New Data](#writing-new-data)
   * [Reading & Writing](#reading-amp-writing)
   * [Indexing](#indexing)
   * [Other Features](#other-features)
 
-### Reading existing Data
+### Reading Existing Data
 
 The simplest usage of the language is to find data stored in the
 database. For that purpose, the following clauses are offered:
@@ -188,7 +188,7 @@ Click
 [here](https://neo4j.com/docs/developer-manual/current/cypher/functions/aggregating/)
 for additional details on how aggregations work.
 
-### Writing new Data
+### Writing New Data
 
 For adding new data, you can use the following clauses.
 
@@ -200,6 +200,9 @@ For adding new data, you can use the following clauses.
 You can still use the `RETURN` clause to produce results after writing, but it
 is not mandatory.
 
+Details on which kind of data can be stored in *Memgraph* can be found in
+[Storable Data Types](data-types.md) chapter.
+
 #### CREATE
 
 This clause is used to add new nodes and edges to the database. The creation
@@ -209,6 +212,12 @@ For example, to create 2 new nodes connected with a new edge, use this query.
 
     CREATE (node1) -[:edge_type]-> (node2)
 
+Labels and properties can be set during creation using the same syntax as in
+[MATCH](#match) patterns. For example, creating a node with a label and a
+property:
+
+    CREATE (node :Label {property: "my property value"}
+
 Additional information on `CREATE` is
 [here](https://neo4j.com/docs/developer-manual/current/cypher/clauses/create/).