Data Types

This section describes the data types that are native to and are supported by the GSQL Query Language. Most of the data objects used in queries come from one of three sources:

  • The query’s input parameters

  • The vertices, edges, and their attributes which are encountered when traversing the graph

  • The variables defined within the query to assist in the computational work of the query

This section covers the following subset of the EBNF language definitions:

EBNF for Data Types
lowercase          := [a-z]
uppercase          := [A-Z]
letter             := lowercase | uppercase
digit              := [0-9]
integer            := ["-"]digit+
real               := ["-"]("."digit+) | ["-"](digit+"."digit*)
numeric            := integer | real
stringLiteral      := '"' [~["] | '\\' ('"' | '\\')]* '"'

name := (letter | "_") [letter | digit | "_"]*   // Can be a single "_" or start with "_"
graphName := name
queryName := name
paramName := name
vertexType := name
edgeType := name
accumName := name
vertexSetName := name
attrName := name
varName := name
tupleType := name
fieldName :=name
funcName := name

type := baseType | tupleType | accumType

baseType := INT
          | UINT
          | FLOAT
          | DOUBLE
          | STRING
          | BOOL
          | VERTEX ["<" vertexType ">"]
          | EDGE
          | JSONOBJECT
          | JSONARRAY
          | DATETIME

filePath := paramName | stringLiteral

typedef := TYPEDEF TUPLE "<" tupleFields ">" tupleType

tupleFields := (baseType fieldName) | (fieldName baseType)
           ["," (baseType fieldName) | (fieldName baseType)]*

parameterType := baseType
               | [ SET | BAG ] "<" baseType ">"
               | FILE

The legacy data type STRING COMPRESS has been deprecated since TigerGraph Server 3.0. You can no longer create new schema with the type STRING COMPRESS. As such, we have removed STRING COMPRESS from the documentation.

Existing schemas that are using STRING COMPRESS can continue to function normally. If you need reference for STRING COMPRESS, please refer to GSQL Language Reference version 3.5 or older.

Identifiers

An identifier is the name for an instance of a language element. In the GSQL query language, identifiers are used to name elements such as a query, a variable, or a user-defined function. In the EBNF syntax, an identifier is referred as name. It can be a sequence of letters, digits, or underscores ("_"). Other punctuation characters are not supported. The initial character can only be a letter or an underscore.

name (identifier)
name := (letter | "_") [letter | digit | "_"]*

Overview

Different types of data can be used in different contexts. The EBNF syntax defines several classes of data types. The most basic is called base type (baseType). The other independent type is FILE. The remaining types are either compound data types built from the independent data types, or supersets of other types. The table below gives an overview of their definitions and their uses.

EBNF term Description Use Case

baseType

INT, UINT, FLOAT, DOUBLE, STRING, BOOL, DATETIME, VERTEX, EDGE,
+ JSONOBJECT, or JSONARRAY

  • Base type variable

  • Query return value

containerType

SET, BAG, LIST, MAP

  • Local container variable

tupleType

Sequence of base types

  • User-defined tuple

accumType

Family of specialized data objects which support accumulation operations

FILE

FILE object

  • Global sequential data object, linked to a text file

parameterType

baseType (except EDGE or JSONOBJECT), a set or bag of baseType, or FILE object

  • Query parameter

elementType

baseType, or identifier

  • Element for most types of container accumulators: SetAccum, BagAccum, GroupByAccum, key of a MapAccum element

type

baseType, identifier, or accumType

  • Element of a ListAccum, value of a MapAccum element

  • Local variable

Base types

The query language supports the following base types, which can be declared and assigned anywhere within their scope. Any of these base types may be used when defining a global variable, a local variable, a query return value, a parameter, part of a tuple, or an element of a container accumulator. Accumulators are described in detail in a later section.

EBNF
baseType := INT
          | UINT
          | FLOAT
          | DOUBLE
          | STRING
          | BOOL
          | VERTEX ["<" vertexType ">"]
          | EDGE
          | JSONOBJECT
          | JSONARRAY
          | DATETIME

The default value of each base type is shown in the table below. The default value is the initial value of a base type variable (see Section "Variable Types" for more details), or the default return value for some functions.

The first seven types (INT, UINT, FLOAT, DOUBLE, BOOL, STRING, and DATETIME) are the same ones mentioned in the "Attribute Data Types" section of GSQL Language Reference, Part 1.

Type Default value Literal

INT

0

A signed integer: -3

UINT

0

An unsigned integer: 5

FLOAT

0

A decimal: 3.14159

DOUBLE

0

A decimal with greater precision than FLOAT

BOOL

false

TRUE or FALSE

STRING

""

Characters enclosed by double quotes: "Hello"

DATETIME

1970-01-01 00:00:00

No literal. Can be converted from a correctly formatted string with to_datetime().

VERTEX

"Unknown"

No literal.

EDGE

No edge: {}

No literal.

JSONOBJECT

An empty object: {}

No literal. Can be converted from a correctly formatted string with parse_json_object().

JSONARRAY

An empty array: []

No literal. Can be converted from a correctly formatted string with parse_json_array().

The FLOAT and DOUBLE data types have the same precision limits as in C++. See Common Errors and Problems for more details.

FLOAT and DOUBLE input values must be in fixed point d.dddd **format, where d is a digit. Output values will be printed in either fixed point for exponential notation, whichever is more compact.

The GSQL Loader can read FLOAT and DOUBLE values with exponential notation (e.g., 1.25 E-7).

Vertex

VERTEX is considered a base type in the GSQL query language. Both query parameters and variables in a query body can be of type VERTEX.

Vertex types

A graph schema defines specific vertex types. Each vertex type has its own set of attributes. The parameter or variable type can be restricted by giving the vertex type in angle brackets <> after the keyword VERTEX. A vertex variable declared without a specifier is called a generic vertex variable.

Generic and typed vertex variables
VERTEX anyVertex;
VERTEX<person> owner;

All vertices have a built-in attribute type. The built-in attribute is of type string. You can access it with the dot (.) operator.

For example, if you declare a vertex variable VERTEX<person> personVertex, then personVertex.type returns "person".

Edge

EDGE is considered a base type in the GSQL query language. Both query parameters and variables in a query body can be of type EDGE.

Edge types

A graph schema defines specific edge types. Each edge type has its own set of attributes. The parameter or variable type can be restricted by giving the edge type in angle brackets <> after the keyword EDGE. An edge variable declared without a specifier is called a generic edge variable.

Generic and typed edge variables
EDGE anyEdge;
EDGE<friendship> friendEdge;

All edges have a built-in attribute type. The built-in attribute is of type string. You can access it with the dot (.) operator.

For example, if you define an edge variable EDGE<friendship> friendEdge, then friendEdge.type returns "Friendship".

Vertex and Edge Attribute Types

The following table maps vertex or edge attribute types in the Data Definition Language (DDL) to GSQL query language types. If an attribute of a vertex or edge is referenced in a GSQL query, they will be automatically converted to their corresponding data type in the GSQL query language.

DDL GSQL Query

INT

INT

UINT

UINT

FLOAT

FLOAT

DOUBLE

DOUBLE

BOOL

BOOL

STRING

STRING

SET< type >

SetAccum< type >

LIST< type >

ListAccum< type >

MAP <key_type, value_type>

MapAccum <key_type, value_type>

DATETIME

DATETIME

JSONOBJECT

A JSONOBJECT instance’s external representation (as input and output) is a string, starting and ending with curly braces ({}) which enclose an unordered list of key-value pairs. JSONOBJECT is immutable. No operator is allowed to alter its value.

Assign a JSONOBJECT value to a base type variable

There is no JSONOBJECT literal in the GSQL query language. Therefore, to assign value to a JSONOBJECT base type variable in GSQL, you need to use the parse_json_object() function to convert a string representation of s JSON object to a JSONOBJECT value.

For example, the following line declares a variable han with a JSONOBJECT value:

JSONOBJECT han = parse_json_object("{\"f_name\": \"Han\", \"l_name\": \"Solo\"}");

JSONARRAY

A JSONARRAY is represented as a string, starting and ending with square brackets ([])which enclose an ordered list of values. JSONARRAY is immutable. No operator is allowed to alter its value.

Assign a JSONARRAY value to a base type variable

There is no JSONARRAY literal in the GSQL query language. Therefore, to assign value to a JSONARRAY base type variable in GSQL, you need to use the parse_json_array() function to convert a string representation of s JSON object to a JSONARRAY value.

For example, the following line declares a variable fruits with a JSONARRAY value:

JSONARRAY fruits = parse_json_array("[\"apple\", \"banana\", \"citrus\"]");

Container types

Container types include the following data types:

  • SET

  • BAG

  • LIST

  • MAP

Table 1. Container types
Type Literal Example Default value

SET

Elements enclosed by parentheses, separated by commas.

(1, 2, 3)

Empty set.

BAG

Elements enclosed by parentheses, separated by commas.

(1, 1, 2)

Empty bag.

LIST

Elements enclosed by square brackets, separated by commas.

[1, 2, 3]

Empty list.

MAP

No literal.

N/A

Empty map.

To see how container type variables are declared in a GSQL query, see Local container variables.

Tuple

A tuple is a user-defined data structure consisting of a fixed sequence of base type variables. Tuple types can be created and named using a TYPEDEF statement. Tuples must be defined first, before any other statements in a query.

EBNF for tuples
typedef := TYPEDEF TUPLE "<" tupleFields ">" tupleType

tupleFields := (baseType fieldName) | (fieldName baseType)
           ["," (baseType fieldName) | (fieldName baseType)]*

A tuple can also be defined in a graph schema and then can be used as a vertex or edge attribute type. A tuple type that has been defined in the graph schema does not need to be re-defined in a query.

The vertex type person contains two complex attributes:

  • secretInfo of type SECRET_INFO, which a user-defined tuple

  • portfolio of type MAP<STRING, DOUBLE>

Investment_Net Schema
TYPEDEF TUPLE <age UINT (4), mothers_name STRING(20) > SECRET_INFO

CREATE VERTEX Person(PRIMARY_ID person_id STRING, portfolio MAP<STRING, DOUBLE>, secret_info SECRET_INFO)

CREATE VERTEX Stock_Order(PRIMARY_ID order_id STRING, ticker STRING, order_size UINT, price FLOAT)

CREATE UNDIRECTED EDGE make_order(FROM Person, TO Stock_Order, order_time DATETIME)

CREATE GRAPH Investment_Net (*)

The query below reads both the SECRET_INFO tuple and the portfolio MAP. The tuple type does not need to be redefined in the query. To read and save the map, we define a MapAccum with the same types for key and value as the portfolio attribute. In addition, the query creates a new tuple type, ORDER_RECORD.

  • Query

  • Result

CREATE QUERY tuple_ex(VERTEX<Person> p) FOR GRAPH Investment_Net{

    TYPEDEF TUPLE <STRING ticker, FLOAT price, DATETIME order_time> Order_Record; (1)

    SetAccum<Secret_Info> @@info; (2)
    ListAccum<Order_Record> @@order_records;
    MapAccum<STRING, DOUBLE> @@portf;

    INIT = {p};

    // Get person p's secret_info and portfolio
    X = SELECT v FROM INIT:v
        ACCUM @@portf += v.portfolio, @@info += v.secret_info;

    // Search person p's orders to record ticker, price, and order time.
    // Note that the tuple gathers info from both edges and vertices.
    orders = SELECT t
        FROM INIT:s -(Make_Order:e)-Stock_Order:t
        ACCUM @@order_records += Order_Record(t.ticker, t.price, e.order_time);

    PRINT @@portf, @@info;
    PRINT @@order_records;
}
1 This statement defines a new tuple Order_Record at the top of the query.
2 Secret_Info has already been defined in Investment_Net Schema.
GSQL > RUN QUERY tuple_ex("person1")
{
  "error": false,
  "message": "",
  "version": {
    "schema": 0,
    "edition": "enterprise",
    "api": "v2"
  },
  "results": [
    {
      "@@info": [{
        "mothers_name": "JAMES",
        "age": 25
      }],
      "@@portf": {
        "AAPL": 3142.24,
        "MS": 5000,
        "G": 6112.23
      }
    },
    {"@@order_records": [
      {
        "ticker": "B",
        "price": 202.32001,
        "order_time": "2017-03-03 18:42:30"
      },
      {
        "ticker": "AAPL",
        "price": 34.42,
        "order_time": "2017-03-03 18:42:28"
      },
      {
        "ticker": "A",
        "price": 50.55,
        "order_time": "2017-03-03 18:42:29"
      }
    ]}
  ]
}

FILE Object

A FILE object is a sequential data storage object, associated with a text file on the local machine.

When referring to a FILE object, we always capitalize the word FILE to distinguish it from ordinary files.

When a FILE object is declared, associated with a particular text file, any existing content in the text file will be erased. During the execution of the query, content written to the FILE will be appended to the FILE. When the query where the FILE was declared finishes running, the FILE contents are saved to the text file.

A FILE object can be passed as a parameter to another query. When a query receives a FILE object as a parameter, it can append data to that FILE, as can every other query which receives this FILE object as a parameter.

Query parameter types

Input parameters to a query can be base type (except EDGE , JSONARRAY, or JSONOBJECT). A parameter can also be a SET or BAG which uses base type (except EDGE , JSONARRAY, or JSONOBJECT) as the element type. A FILE object can also be a parameter. Within the query, SET and BAG are converted to SetAccum and BagAccum, respectively.

A query parameter is immutable. It cannot be assigned a new value within the query.

The FILE object is a special case. It is passed by reference, meaning that the receiving query gets a link to the original FILE object. The receiving query can write to the FILE object.

EBNF
parameterType := INT
               | UINT
               | FLOAT
               | DOUBLE
               | STRING
               | BOOL
               | VERTEX ["<" vertexType ">"]
               | DATETIME
               | [ SET | BAG ] "<" baseType ">"
               | FILE
Examples of collection type parameters
(SET<VERTEX<person> p1, BAG<INT> ids, FILE f1)