Date and time schema

Date and time are two data types that are commonly used for both vertex and edge properties.

Create schema and load data

Create the following properties in a graph:

// SCHEMA FOR DATE AND TIME PROPERTIES
schema.propertyKey('year').Date().ifNotExists().create()
schema.propertyKey('time').Time().ifNotExists().create()

Some additional schema is required for the example queries below:

// OTHER PROPERTIES
schema.propertyKey('name').Text().ifNotExists().create()
schema.propertyKey('gender').Text().ifNotExists().create()// VERTEX LABELS
schema.vertexLabel('person').properties('name', 'gender').ifNotExists().create()
// EDGE LABELS
schema.edgeLabel('born').multiple().connection('person','person').ifNotExists().create()
schema.edgeLabel('born').properties('year','time').add()
// INDEXES
schema.vertexLabel('person').index('byName').materialized().by('name').add()

This example uses the date and time properties on the edge label born that identifies the birthdate and birth time for a person.

The following data is inserted using DSE Graph Loader:

A CSV file of each person:

name|gender
Julia Child|F
JCMom|F
Simone Beck|F
SBMom|F
Louisette Bertholie|F
LBMom|F

and a CSV file for the edges:

pname1|pname2|year|time
Julia Child|JCMom|1930-01-01|10:00:00.000
Simone Beck|SBMom|1940-01-01|12:00:00.000
Louise Bertholie|LBMom|1950-01-01|13:00:00.000

The mapping script loads each file after the schema has been created in a graph:

/* SAMPLE INPUT
person: Julia Child|F
personEdges: Julia Child|JCMom|1930-01-01|10:00
 */

// CONFIGURATION
// Configures the data loader to create the schema
config dryrun: false, preparation: true, create_schema: false, load_new: true, schema_output: 'loader_output.txt'

// DATA INPUT
// Define the data input source (a file which can be specified via command line arguments)
// inputfiledir is the directory for the input files
inputfiledir = '/tmp/dateTime/'
personInput = File.csv(inputfiledir + "person.csv").delimiter('|')
personEdgeInput = File.csv(inputfiledir + "personEdges.csv").delimiter('|')

//Specifies what data source to load using which mapper (as defined inline)

load(personInput).asVertices {
    label "person"
    key "name"
}

load(personEdgeInput).asEdges {
    label "born"
    outV "pname1", {
        label "person"
        key "name"
    }
    inV "pname2", {
        label "person"
        key "name"
    }
}

Querying date and time data
Find all born edges that have a birthdate earlier than 1940-01-01:
```
// Find all edges that have a birthdate earlier than 1940-01-01
g.V().hasLabel('person').outE('born').has('year',lt('1940-01-01')).valueMap()
```
This query finds all vertices with a label person, than traverses the outgoing edges labelled born, and filters out all edges found to meet the limitation of lt('1940-01-01').
```
{year=1930-01-01, time=10:00}
```
List the name of each child and their parent based on having a birthdate earlier than 1940-01-01:
```
g.V().hasLabel('person').as('child').
outE('born').has('year',lt('1940-01-01')).inV().as('parent').
select('child','parent').
by('name').
by('name')
```
This query finds all vertices with a label person and saves it temporarily as child, than traverses the outgoing edges labelled born, and filters out all edges found to meet the limitation of lt('1940-01-01') as the last query did. It continues by finding all the incoming vertices and saves them temporarily as parent, before selecting the two saved items with a select() method, by name in each case.
```
{child=Julia Child, parent=JCMom}
```

Date and time schema

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