From 0324b61e0bc7769b2736417e6ac0c0f3d24bf2bc Mon Sep 17 00:00:00 2001
From: Teon Banek <teon.banek@memgraph.io>
Date: Wed, 19 Jul 2017 14:48:20 +0200
Subject: [PATCH] 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 | 1 +
docs/user_technical/data-types.md | 36 ++++++++++++++++++++++++++++++
docs/user_technical/open-cypher.md | 17 ++++++++++----
3 files changed, 50 insertions(+), 4 deletions(-)
create mode 100644 docs/user_technical/data-types.md
diff --git a/docs/user_technical/README.md b/docs/user_technical/README.md
index 14b2118ee..adebcb4fe 100644
--- a/docs/user_technical/README.md
+++ b/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)
diff --git a/docs/user_technical/data-types.md b/docs/user_technical/data-types.md
new file mode 100644
index 000000000..4388211f1
--- /dev/null
+++ b/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.
diff --git a/docs/user_technical/open-cypher.md b/docs/user_technical/open-cypher.md
index 205f3f8be..d00cfb1e6 100644
--- a/docs/user_technical/open-cypher.md
+++ b/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/).