adambard/learnxinyminutes-docs
1
1
Fork 0
mirror of https://github.com/adambard/learnxinyminutes-docs.git synced 2024-11-23 06:03:07 +03:00
Code Issues Projects Releases Wiki Activity

Fix build error in 'build/docs/cypher/index.html'

Browse Source
This commit is contained in:
Divay Prakash 2018-08-15 18:05:24 +05:30
parent f1bdf8f892
commit cbc69e807b
1 changed files with 17 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

34
cypher.html.markdown
View File

@ -16,19 +16,19 @@ Nodes
**Represents a record in a graph.**
```()```
`()`
It's an empty *node*, to indicate that there is a *node*, but it's not relevant for the query.
```(n)```
`(n)`
It's a *node* referred by the variable **n**, reusable in the query. It begins with lowercase and uses camelCase.
```(p:Person)```
`(p:Person)`
You can add a *label* to your node, here **Person**. It's like a type / a class / a category. It begins with uppercase and uses camelCase.
```(p:Person:Manager)```
`(p:Person:Manager)`
A node can have many *labels*.
```(p:Person {name : 'Théo Gauchoux', age : 22})```
`(p:Person {name : 'Théo Gauchoux', age : 22})`
A node can have some *properties*, here **name** and **age**. It begins with lowercase and uses camelCase.
The types allowed in properties :
@ -40,7 +40,7 @@ The types allowed in properties :
*Warning : there isn't datetime property in Cypher ! You can use String with a specific pattern or a Numeric from a specific date.*
```p.name```
`p.name`
You can access to a property with the dot style.
@ -49,16 +49,16 @@ Relationships (or Edges)
**Connects two nodes**
```[:KNOWS]```
`[:KNOWS]`
It's a *relationship* with the *label* **KNOWS**. It's a *label* as the node's label. It begins with uppercase and use UPPER_SNAKE_CASE.
```[k:KNOWS]```
`[k:KNOWS]`
The same *relationship*, referred by the variable **k**, reusable in the query, but it's not necessary.
```[k:KNOWS {since:2017}]```
`[k:KNOWS {since:2017}]`
The same *relationship*, with *properties* (like *node*), here **since**.
```[k:KNOWS*..4]```
`[k:KNOWS*..4]`
It's a structural information to use in a *path* (seen later). Here, **\*..4** says "Match the pattern, with the relationship **k** which be repeated between 1 and 4 times.
@ -67,16 +67,16 @@ Paths
**The way to mix nodes and relationships.**
```(a:Person)-[:KNOWS]-(b:Person)```
`(a:Person)-[:KNOWS]-(b:Person)`
A path describing that **a** and **b** know each other.
```(a:Person)-[:MANAGES]->(b:Person)```
`(a:Person)-[:MANAGES]->(b:Person)`
A path can be directed. This path describes that **a** is the manager of **b**.
```(a:Person)-[:KNOWS]-(b:Person)-[:KNOWS]-(c:Person)```
`(a:Person)-[:KNOWS]-(b:Person)-[:KNOWS]-(c:Person)`
You can chain multiple relationships. This path describes the friend of a friend.
```(a:Person)-[:MANAGES]->(b:Person)-[:MANAGES]->(c:Person)```
`(a:Person)-[:MANAGES]->(b:Person)-[:MANAGES]->(c:Person)`
A chain can also be directed. This path describes that **a** is the boss of **b** and the big boss of **c**.
Patterns often used (from Neo4j doc) :
@ -230,13 +230,13 @@ DELETE n, r
Other useful clauses
---
```PROFILE```
`PROFILE`
Before a query, show the execution plan of it.
```COUNT(e)```
`COUNT(e)`
Count entities (nodes or relationships) matching **e**.
```LIMIT x```
`LIMIT x`
Limit the result to the x first results.