openCypher in GSQL

openCypher is a popular open-source declarative query language for property graphs. More about openCypher can be found at openCypher.org.

TigerGraph’s GSQL query language supports many openCypher features. This page lists the features currently supported and features not yet supported .

To see how to run openCypher on the TigerGraph platform, see openCypher in GSQL.

openCypher Features in GSQL

Clauses

Clause Description

DELETE

Delete graph elements — nodes and relationships.

Any node to be deleted must also have all associated relationships explicitly deleted.

DETACH DELETE

Writing Delete a node or set of nodes.

All associated relationships will automatically be deleted.

LIMIT

Reading sub-clause A sub-clause used to constrain the number of records in the output.

MATCH

Reading Specify the patterns to search for in the database.

MANDATORY MATCH

Reading Specify the patterns to search for in the database, and fail if no match is found.

ORDER BY [ASC[ENDING] DESC[ENDING]]

Reading sub-clause A sub-clause following

RETURN or WITH

Specifying that the output should be sorted in either ascending (the default) or descending order.

RETURN … [AS]

Projecting Defines what to include in the query result set.

SKIP

Reading/Writing A sub-clause defining from which record to start including the records in the output.

WITH … [AS]

Projecting Allows query parts to be chained together, piping the results from one to be used as starting points or criteria in the next.

See below for restrictions.

WHERE

Reading sub-clause A sub-clause used to add constraints to the patterns in a MATCH clause, or to filter the results of a WITH clause.

Operators

% Mathematical Modulo division

*

Mathematical Multiplication

+

Mathematical Addition

+

String Concatenation

+

List Concatenation

-

Mathematical Subtraction or unary minus

.

General Property access

/

Mathematical Division

<

Comparison Less than

< =

Comparison Less than or equal to

<>

Comparison Inequality

=

Comparison Equality

>

Comparison Greater than

>=

Comparison Greater than or equal to

AND

Boolean Conjunction

CONTAINS

String comparison Case-sensitive inclusion search

DISTINCT

General Duplicate removal

ENDS WITH

String comparison Case-sensitive suffix search

IN List

List element existence check

IS NOT NULL

Comparison Non-null check

IS NULL

Comparison null check

NOT

Boolean Negation

OR

Boolean Disjunction

STARTS WITH

String comparison Case-sensitive prefix search

XOR

Boolean Exclusive disjunction

[ ]

General Subscript (dynamic property access)

[ ]

List Subscript (accessing element(s) in a list)

^

Mathematical Exponentiation

Functions

left() String Returns a string containing the specified number of leftmost characters of the original string.

right()

String Returns a string containing the specified number of rightmost characters of the original string.

reverse()

String Returns a string in which the order of all characters in the original string have been reversed.

lTrim()

String Returns the original string with leading whitespace removed.

replace()

String Returns a string in which all occurrences of a specified string in the original string have been replaced by another (specified) string.

rTrim()

String Returns the original string with trailing whitespace removed.

trim()

String Returns the original string with leading and trailing whitespace removed.

acos()

Trigonometric Returns the arccosine of a number in radians.

asin()

Trigonometric Returns the arcsine of a number in radians.

atan()

Trigonometric Returns the arctangent of a number in radians.

atan2()

Trigonometric Returns the arctangent2 of a set of coordinates in radians.

ceil()

Numeric Returns the smallest floating point number that is greater than or equal to a number and equal to a mathematical integer.

cot()

Trigonometric Returns the cotangent of a number.

degrees()

Trigonometric Converts radians to degrees.

exp()

Logarithmic Returns e^n, where e is the base of the natural logarithm, and n is the value of the argument expression.

floor()

Numeric Returns the largest floating point number that is less than or equal to a number and equal to a mathematical integer.

log()

Logarithmic Returns the natural logarithm of a number.

log10()

Logarithmic Returns the common logarithm (base 10) of a number.

pi()

Trigonometric Returns the mathematical constant pi.

radians()

Trigonometric Converts degrees to radians.

rand()

Numeric Returns a random floating point number in the range from 0 (inclusive) to 1 (exclusive); i.e. [0, 1).

round()

Numeric Returns the value of a number rounded to the nearest integer.

sign()

Numeric Returns the signum of a number: 0 if the number is 0, -1 for any negative number, and 1 for any positive number.

sin()

Trigonometric Returns the sine of a number.

sqrt()

Logarithmic Returns the square root of a number.

stDev()

Aggregating Returns the standard deviation for the given value over a group for a sample of a population.

tan()

Trigonometric Returns the tangent of a number.

abs()

Numeric Returns the absolute value of a number.

avg()

Aggregating Returns the average of a set of values.

coalesce()

Scalar Returns the first non-null value in a list of expressions.

cos()

Trigonometric Returns the cosine of a number.

count()

Aggregating Returns the number of values or records.

max()

Aggregating Returns the maximum value in a set of values.

min()

Aggregating Returns the minimum value in a set of values.

sum()

Aggregating Returns the sum of a set of numeric values.

type()

Scalar Returns the string representation of the relationship type.

toLower()

String Returns the original string in lowercase.

toString()

String Converts an integer, float or boolean value to a string.

toUpper()

String Returns the original string in uppercase.

substring()

String Returns a substring of the original string, beginning with a 0-based index start and length.

e()

Logarithmic Returns the base of the natural logarithm, e.

timestamp()

Scalar Returns the difference, measured in milliseconds, between the current time and midnight, January 1, 1970 UTC.

Expressions

CASE Expression

A generic conditional expression, similar to if/else statements available in other languages.

openCypher Features Not Yet Supported

Clauses

OPTIONAL MATCH Reading Specify the patterns to search for in the database while using nulls for missing parts of the pattern.

CALL […YIELD]

Reading/Writing Invoke a procedure deployed in the database.

CREATE

Writing create nodes and relationships.

MERGE

Reading/Writing Ensures that a pattern exists in the graph. Either the pattern already exists, or it needs to be created.

REMOVE

Writing Remove properties and labels from nodes and relationships.

UNION

Set operations Combines the result of multiple queries. Duplicates are removed.

UNION ALL

Set operations Combines the result of multiple queries. Duplicates are retained.

UNWIND … [AS]

Projecting Expands a list into a sequence of records.

SET

Writing Update labels on nodes and properties on nodes and relationships.

Operators

N/A

Functions

collect() Aggregating Returns a list containing the values returned by an expression.

endNode()

Scalar Returns the end node of a relationship.

exists()

Predicate Returns true if a match for the pattern exists in the graph, or if the specified property exists in the node, relationship or map.

head()

Scalar Returns the first element in a list.

id()

Scalar Returns the id of a relationship or node.

keys()

List Returns a list containing the string representations for all the property names of a node, relationship, or map.

labels()

List Returns a list containing the string representations for all the labels of a node.

last()

Scalar Returns the last element in a list.

length()

Scalar Returns the length of a path.

nodes()

List Returns a list containing all the nodes in a path.

properties()

Scalar Returns a map containing all the properties of a node or relationship.

range()

List Returns a list comprising all integer values within a specified range.

relationships()

List Returns a list containing all the relationships in a path.

size()

Scalar Returns the number of items in a list.

size()

Applied to pattern expression Scalar Returns the number of subgraphs matching the pattern expression. size() applied to string Scalar Returns the size of a string.

split()

String Returns a list of strings resulting from the splitting of the original string around matches of the given delimiter.

startNode()

Scalar Returns the start node of a relationship.

tail()

List Returns all but the first element in a list.

reverse()

List Returns a list in which the order of all elements in the original list have been reversed.

stDevP()

Aggregating Returns the standard deviation for the given value over a group for an entire population → coming soon

percentileCont()

Aggregating Returns the percentile of the given value over a group using linear interpolation.

percentileDisc()

Aggregating Returns the nearest value to the given percentile over a group using a rounding method.

toBoolean()

Scalar Converts a string value to a boolean value.

toFloat()

Scalar Converts an integer or string value to a floating point number.

toInteger()

Scalar Converts a floating point or string value to an integer value.

Syntax

Certain openCypher syntax is also not supported.

  • Queries with a WITH clause that does not implicitly group by exactly one vertex variable.

    1. 0 vertex variables as group key

      MATCH (u:User {name: "John") // find all users with the same friend count as John
      WITH     u.friendCount AS fc   // note, u not included in group key list
      MATCH  (o:User {friendCount: fc})
      …
    2. More than 1 vertex variables as group key

      MATCH (u1) -[:communication]- (x) -[:communication]- (u2)
      WITH     u1, u2, COUNT(x) // we support only u1 or only u2 in list
      …
  • Queries introducing path variables

    MATCH p = (u1) -[e1:communication]- (x) -[e2:communication]- (u2)	// p is path var
    …
  • Queries whose MATCH pattern does not include at least one vertex variable from immediately preceding WITH clause.

    MATCH (u:user) -[:communication]- (o)
    WITH     u, …
    MATCH (x) -[:communication]-(y)		// this pattern must refer to u
    …
  • Queries with disconnected MATCH pattern fragments

    MATCH (x:user), (y:user)
    WHERE x.friendCount = y.friendCount
    …
  • Pattern fragments (x:user) and (y:user) are not connected by edge traversal or by sharing vertex variables.