Basic Traversals¶

This guide covers the fundamentals of traversing graphs with Gremlin in Grafeo.

Starting a Traversal¶

All Gremlin traversals start with the graph reference g:

// All vertices
g.V()

// All edges
g.E()

// Vertex by ID
g.V(1)

// Multiple vertices by ID
g.V(1, 2, 3)

Filtering by Label¶

Use hasLabel() to filter vertices or edges by their label:

// All Person vertices
g.V().hasLabel('Person')

// Multiple labels
g.V().hasLabel('Person', 'Company')

Filtering by Property¶

Use has() to filter by property values:

// Property equals value
g.V().has('name', 'Alice')

// Property exists (any value)
g.V().has('email')

// Label + property shorthand
g.V().has('Person', 'name', 'Alice')

Predicate Filters¶

Use P.* predicates for comparison operators:

// Greater than
g.V().has('age', P.gt(25))

// Greater than or equal
g.V().has('age', P.gte(25))

// Less than
g.V().has('age', P.lt(40))

// Less than or equal
g.V().has('age', P.lte(40))

// Not equal
g.V().has('status', P.neq('inactive'))

// Between (inclusive start, exclusive end)
g.V().has('age', P.between(25, 40))

// Within a set of values
g.V().has('status', P.within('active', 'pending'))

// Not within a set
g.V().has('role', P.without('admin', 'superuser'))

String Predicates¶

// Contains substring
g.V().has('name', P.containing('Ali'))

// Starts with
g.V().has('name', P.startingWith('A'))

// Ends with
g.V().has('email', P.endingWith('@company.com'))

Negation Filters¶

// Property does NOT exist
g.V().hasNot('deleted')

// Filter by ID
g.V().hasId(42)

// Filter by multiple IDs
g.V().hasId(1, 2, 3)

Deduplication¶

// Remove duplicate results
g.V().out('KNOWS').dedup()

Limiting and Skipping¶

// First 10 results
g.V().limit(10)

// Skip first 5
g.V().skip(5)

// Range (skip 5, take 10)
g.V().range(5, 15)

Python Example¶

import grafeo

db = grafeo.GrafeoDB()

# Create data
db.execute("INSERT (:Person {name: 'Alice', age: 30})")
db.execute("INSERT (:Person {name: 'Bob', age: 25})")

# Basic traversal
result = db.execute_gremlin("g.V().hasLabel('Person')")
for row in result:
    print(row)

# Filter by property
result = db.execute_gremlin("g.V().has('name', 'Alice')")

Supported Predicates¶

Predicate	Description
`P.eq(value)`	Equal to
`P.neq(value)`	Not equal to
`P.gt(value)`	Greater than
`P.gte(value)`	Greater than or equal
`P.lt(value)`	Less than
`P.lte(value)`	Less than or equal
`P.within(values...)`	In a set of values
`P.without(values...)`	Not in a set of values
`P.between(start, end)`	Between (inclusive start, exclusive end)
`P.containing(str)`	Contains substring
`P.startingWith(str)`	Starts with prefix
`P.endingWith(str)`	Ends with suffix