Queries

A GSQL query is a sequence of data retrieval-and-computation statements executed as a single operation. Users can write queries to explore a data graph however they like, to read and make computations on the graph data along the way, to update the graph, and to deliver resulting data. A query is analogous to a user-defined procedure or function: it can have one or more input parameters, and it can produce output in two ways: by returning a value or by printing.

EBNF for CREATE QUERY
createQuery := CREATE [OR REPLACE] [DISTRIBUTED] QUERY queryName
               "(" [parameterList] ")"
               [FOR GRAPH graphName]
               [RETURNS "("  baseType | accumType ")"]
               [API "(" stringLiteral ")"]
               [SYNTAX syntaxName]
               "{" queryBody "}"

interpretQuery := INTERPRET QUERY "(" ")"
               [FOR GRAPH graphName]
               [SYNTAX syntaxName]
               "{" queryBody "}"

parameterValueList := parameterValue ["," parameterValue]*
parameterValue := parameterConstant
                | "[" parameterValue ["," parameterValue]* "]"  // BAG or SET
                | "(" stringLiteral "," stringLiteral ")"        // generic VERTEX value
parameterConstant := numeric | stringLiteral | TRUE | FALSE
parameterList := parameterType paramName ["=" constant]
                 ["," parameterType paramName ["=" constant]]*

syntaxName := name

queryBody := [typedefs] [declStmts] [declExceptStmts] queryBodyStmts
typedefs := (typedef ";")+
declStmts := (declStmt ";")+
declStmt := baseDeclStmt | accumDeclStmt | fileDeclStmt
declExceptStmts := (declExceptStmt ";")+
queryBodyStmts := (queryBodyStmt ";")+

installQuery := INSTALL QUERY [installOptions] ( "*" | ALL |queryName ["," queryName]* )
runQuery := RUN QUERY [runOptions] queryName "(" parameterValueList ")"

showQuery := SHOW QUERY queryName
dropQuery := DROP QUERY ( "*" | ALL | queryName ["," queryName]* )

A query can be run in one of three ways:

  1. Define and run an unnamed query immediately:

    1. INTERPRET QUERY: execute the query’s statements

      Alternately, there is also a built-in REST++ endpoint to interpret a query string:
      POST /gsqlserver/interpreted_query
      See the RESTPP API User Guide for details.

  2. Define a named query and then run it.

    1. CREATE QUERY: define the functionality of the query

    2. INTERPRET QUERY: execute the query with input values

  3. Define a named query, compile it to optimize performance, and then run it.

    1. CREATE QUERY: define the functionality of the query

    2. INSTALL QUERY: compile the query

    3. RUN QUERY: execute the query with input values

There are some limitations to Interpreted Mode. See the section on Interpret a created query and the appendix section Interpreted GSQL Limitations.

CREATE QUERY

createQuery := CREATE [OR REPLACE] [DISTRIBUTED] QUERY queryName
               "(" [parameterList] ")"
               [FOR GRAPH graphName]
               [RETURNS "("  baseType | accumType ")"]
               [API ( v2 )]
               [SYNTAX syntaxName]
               "{" queryBody "}"

queryBody := [typedefs] [declExceptStmts] queryBodyStmts

CREATE QUERY defines the functionality of a query on a given graph schema.

A query has a name, a parameter list, the name of the graph being queried, an optional RETURNS type (see Section "RETURN Statement" for more details), optional specifiers for the output API and the language syntax version, and a body. The body consists of an optional sequence of typedefs, followed by an optional sequence of declarations, then followed by one or more statements. The body defines the behavior of the query.

Parameters

OR REPLACE

If the optional keywords OR REPLACE are included, then this query definition, if error-free, replaces a previous definition with the same query name. If the original query was installed, you’ll need to reinstall the new query.

However, if there are any errors in this query definition, then the previous query definition is maintained. If the OR REPLACE option is not used, GSQL rejects a CREATE QUERY command that uses an existing name.

Only the query owner is allowed to run CREATE OR REPLACE on a query. However, if you have the WRITE_QUERY RBAC privilege on the corresponding graph, you can execute DROP QUERY to drop the query and create a new one with the same name.

The difference between CREATE OR REPLACE and dropped the query and recreating a query are the following:

  • Only the query owner is allowed to run CREATE OR REPLACE on a query directly, while anyone with the WRITE_QUERY privilege on the corresponding graph and drop and recreate the query.

  • The ACLs on the original query are dropped when you drop the query. CREATE OR REPLACE keeps the original ACLs intact.
DISTRIBUTED

The DISTRIBUTED option applies only to installations where the graph has been distributed across a cluster. If specified, the query will run with a different execution model which may give better performance for queries that traverse a large portion of the cluster.For details, see Distributed Query Mode.

queryName

Name of the query.

parameterList

A list of parameters for the query. The parameter list for a query follows the following form:

parameterType paramName ["=" constant] ["," parameterType paramName  ["=" constant]]*

For a list of allowed data types for query parameters, see Query parameter types.

FOR GRAPH graphName

Specifies the graph that the query is created on. This clause is optional if you have already specified a working graph either when entering GSQL or through the USE GRAPH command.

RETURNS clause

The optional RETURNS clause makes the query a subquery and specifies the data type to be returned in the RETRUN statement of the subquery. For more information, see Subqueries.

API v2

Specifies the JSON output format. The only option is v2.

SYNTAX syntaxName

Specifies the GSQL syntax version to be used by the query. See the Query Language Syntax Versions for an outline of the differences. See Pattern Matching tutorial for details on v2.

queryBody

The query body contains a sequence of data retrieval-and-computation statements.

Typedefs allow the definition of custom types for use within the body. The declarations support the definition of accumulators (see Chapter "Accumulators" for more details) and global/local variables. All accumulators and global variables must be declared before any statements.There are various types of statements that can be used within the body.

Typically, the core statement(s) in the body of a query is one or more SELECT, UPDATE, INSERT, DELETE statements. The language supports conditional statements such as an IF statement as well as looping constructs such as WHILE and FOREACH. It also supports calling functions, assigning variables, printing, and modifying the graph data.

The query body may include calls to other queries. That is, the other queries are treated as subquery functions. See the subsection on "subqueries".

Examples

Example of a CREATE QUERY statement
CREATE QUERY create_query_ex (STRING uid) FOR GRAPH Social_Net RETURNS (int) SYNTAX v2 {
    // declaration statements
    users = {Person.*};
    // body statements
    posts = SELECT p
        FROM users:u-(Posted>)-:p
        WHERE u.id == uid;
    PRINT posts;
    RETURN posts.size();
}

Default query parameter values

You can specify default values for parameters of primitive types when creating a query. Primitive types include:

  • INT

  • UINT

  • FLOAT

  • DOUBLE

  • STRING

  • BOOL

  • STRING

  • DATETIME

To specify the default value for a parameter, use the assignment operator (=) after the parameter name and specify the default value:

Example of a CREATE QUERY command with a default parameter value
CREATE QUERY create_query_ex (STRING uid = "Tom") FOR GRAPH Social_Net RETURNS (int) SYNTAX v2 {
    // declaration statements
    users = {Person.*};
    // body statements
    posts = SELECT p
        FROM users:u-(Posted>)-:p
        WHERE u.id == uid;
    PRINT posts;
    RETURN posts.size();
}

Dynamic querying

TigerGraph 3.0+ supports Dynamic Querying. This means the query can be written and installed as a saved procedure without referencing a particular graph.Schema details — the name of the graph, vertex types, edge types, and attributes — can all be parameterized and only need to be specified at run time.

Here are the ingredients for a dynamic query:

  • Graph name: When creating a query, FOR GRAPH graphName is optional, as long as the graph has been specified already, either when entering gsql: GSQL -g graphName [<gsql_command>] or once inside the GSQL shell, by using the USE GRAPH graphName command.

  • Vertex type and edge type in SELECT statements. Typically, the FROM clause mentions the name of specific vertex types and edge types. String or string set parameters can be used for edge and target types instead.

  • Attribute names. The getAttr and setAttr functions, which take attribute name and data type as string parameters, can be used to parameterize attribute access.

  • INSERT statements: If you are using INSERT to add data to your graph, you need to specify what type of vertex or edge you want to add.This can also be parameterized.

The following example demonstrates Dynamic GSQL Query techniques using the PageRank algorithm from our Graph Data Science library. The query is written with schema information embedded statically in it:

  • graph name = social

  • vertex type = Page

  • edge type = Link

  • vertex attribute = Score

  • Embedded schema

  • Dynamic querying

CREATE QUERY page_rank (FLOAT max_change=0.00, INT max_iter=25,
    FLOAT damping=0.85)  // parameters
    FOR GRAPH Gsql_Demo
    {
    MaxAccum<float> @@max_diff = 9999;
    SumAccum<float> @rcvd_score = 0;
    SumAccum<float> @score = 1;

    Start = {Page.*};
    WHILE @@maxDiff > max_change LIMIT max_iter DO
        @@maxDiff = 0;
        V = SELECT s
            FROM Start:s -(Linkto:e)- Page:t       // hardcoded types
            ACCUM t.@rcvd_score += s.@score/(s.outdegree("Linkto")) // Param
            POST-ACCUM s.@score = (1.0-damping) + damping * s.@rcvd_score, s.@rcvd_score = 0, @@max_diff += abs(s.@score - s.@score');
    END;

    V = SELECT s FROM Start:s
      POST-ACCUM s.Score = s.@score;    // hardcoded attribute
}
CREATE QUERY pagerank_dyn (FLOAT max_change=0.00, INT max_iter=25,
  FLOAT damping=0.85, STRING v_type, STRING e_type, STRING attr)
{
    MaxAccum<FLOAT> @@max_diff = 9999;
    SumAccum<FLOAT> @rcvd_score = 0;
    SumAccum<FLOAT> @score = 1;

    Start = {v_type};
    WHILE @@max_diff > max_change LIMIT max_iter DO
        @@max_diff = 0;
        V = SELECT s
            FROM Start:s -(e_type:e)- v_type:t // Parameterized
            ACCUM t.@rcvd_score += s.@score/(s.outdegree(e_type)) //param
            POST-ACCUM s.@score = (1.0-damping) + damping * s.@rcvd_score,
                s.@rcvd_score = 0,
                @@max_diff += abs(s.@score - s.@score');
    END;

    V = SELECT s FROM Start:s
        POST-ACCUM s.setAttr(attr, s.@score); // Parameterized
}
RUN QUERY pagerank_dyn(_,_,_,"Page", "Link", "Score")

Statement types

A statement is a standalone instruction that expresses an action to be carried out.The most common statements are data manipulation language (DML) statements. DML statements include the SELECT, UPDATE, INSERT INTO, DELETE FROM, and DELETE statements.

A GSQL query has two levels of statements. The upper-level statement type is called query-body-level statement, or *query-body statement* for short. This statement type is part of either the top-level block or a query-body control flow block.For example, each of the statements at the top level directly under CREATE QUERY is a query-body statement. If one of the statements is a CASE statement with several THEN blocks, each of the statements in the THEN blocks is also a query-body statement.Each query-body statement ends with a semicolon.

The lower-level statement type is called DML-sub-level statement or DML-sub statement for short. This statement type is used inside certain query-body DML statements, to define particular data manipulation actions.DML-sub-statements are comma-separated. There is no comma or semicolon after the last DML-sub-statement in a block. For example, one of the top-level statements is a SELECT statement, each of the statements in its ACCUM clause is a DML-sub-statement. If one of those DML-sub-statements is a CASE statement, each of the statement in the THEN blocks is a DML-sub-statement.

There is some overlap in the types. For example, an assignment statement can be used either at the query-body level or the DML-sub-level.

queryBodyStmts := (queryBodyStmt ";")+

queryBodyStmt := assignStmt           // Assignment
               | vSetVarDeclStmt      // Declaration
               | gAccumAssignStmt     // Assignment
               | gAccumAccumStmt      // Assignment
               | lAccumAccumStmt      // Assignment
               | funcCallStmt         // Function Call
               | selectStmt           // Select
               | queryBodyCaseStmt    // Control Flow
               | queryBodyIfStmt      // Control Flow
               | queryBodyWhileStmt   // Control Flow
               | queryBodyForEachStmt // Control Flow
               | BREAK                // Control Flow
               | CONTINUE             // Control Flow
               | updateStmt           // Data Modification
               | insertStmt           // Data Modification
               | queryBodyDeleteStmt  // Data Modification
               | printStmt            // Output
               | printlnStmt          // Output
               | logStmt              // Output
               | returnStmt           // Output
               | raiseStmt            // Exception
               | tryStmt              // Exception

DMLSubStmtList := DMLSubStmt ["," DMLSubStmt]*

DMLSubStmt := assignStmt           // Assignment
            | funcCallStmt         // Function Call
            | gAccumAccumStmt      // Assignment
            | lAccumAccumStmt      // Assignment
            | attrAccumStmt        // Assignment
            | vAccumFuncCall       // Function Call
            | localVarDeclStmt     // Declaration
            | DMLSubCaseStmt       // Control Flow
            | DMLSubIfStmt         // Control Flow
            | DMLSubWhileStmt      // Control Flow
            | DMLSubForEachStmt    // Control Flow
            | BREAK                // Control Flow
            | CONTINUE             // Control Flow
            | insertStmt           // Data Modification
            | DMLSubDeleteStmt     // Data Modification
            | printlnStmt          // Output
            | logStmt              // Output

Guidelines for understanding statement type hierarchy:

  • Top-level statements are Query-Body type (each statement ending with a semicolon).

  • The statements within a DML statement are DML-sub statements (comma-separated list).

  • The blocks within a Control Flow statement have the same type as the entire Control Flow statement itself.

Schematic illustration of relationship between queryBodyStmt and DMLSubStmt
CREATE QUERY stmt_types (parameterList) FOR GRAPH g [
	other queryBodyStmt1;
	ControlFlow queryBodyStmt2   // ControlFlow inside top level.
		other queryBodyStmt2.1;      // subStmts in ControlFlow are queryBody unless inside DML.
		ControlFlow queryBodyStmt2.2 // ControlFlow inside ControlFlow inside top level
			other queryBodyStmt2.2.1;
			other queryBodyStmt2.2.2;
		END;
		DML queryBodyStmt2.3     // DML inside ControlFlow inside top-level
			other DMLSubStmt2.3.1,   // switch to DMLSubStmt
			other DMLSubStmt2.3.2
		;
	END;
	DML queryBodyStmt3           // DML inside top level.
		other DMLSubStmt3.1,      // All subStmts in DML must be DMLSubStmt type
		ControlFlow DMLSubStmt3.2 // ControlFlow inside DML inside top level
			other DMLSubStmt3.2.1,
			other DMLSubStmt3.2.2
		,
		DML DMLsubStmt3.3
			other DMLSubStmt3.3.1,
			other DMLSubStmt3.3.2
	;
	other queryBodyStmt4;

Here is a descriptive list of query-body statements:

EBNF term Common Name Description

assignStmt

Assignment Statement

See "Declaration and Assignment Statements"

vSetVarDeclStmt

Vertex Set Variable Declaration Statement

See "Declaration and Assignment Statements"

gAccumAssignStmt

Global Accumulator Assignment Statement

See "Declaration and Assignment Statements"

gAccumAccumStmt

Global Accumulator Accumulation Statement

See "Declaration and Assignment Statements"

lAccumAccumStmt

Local Accumulator Accumulation Statement

See "Declaration and Assignment Statements"

funcCallStmt

Functional Call or Query Call Statement

See "Declaration and Assignment Statements"

selectStmt

SELECT Statement

See "SELECT Statement"

queryBodyCaseStmt

query-body CASE statement

See "Control Flow Statements"

queryBodyIfStmt

query-body IF statement

See "Control Flow Statements"

queryBodyWhileStmt

query-body WHILE statement

See "Control Flow Statements"

queryBodyForEachStmt

query-body FOREACH statement

See "Control Flow Statements"

updateStmt

UPDATE Statement

See "Data Modification Statements"

insertStmt

INSERT INTO statement

See "Data Modification Statements"

queryBodyDeleteStmt

Query-body DELETE Statement

See "Data Modification Statements"

printStmt

PRINT Statement

See "Output Statements"

logStmt

LOG Statement

See Output Statements"

returnStmt

RETURN Statement

See "Output Statements"

raiseStmt

PRINT Statement

See "Exception Statements"

tryStmt

TRY Statement

See "Exception Statements"

Here is a descriptive list of DML-sub-statements:

EBNF term Common Name Description

assignStmt

Assignment Statement

See "Declaration and Assignment Statements"

funcCallStmt

Functional Call Statement

See "Declaration and Assignment Statements"

gAccumAccumStmt

Global Accumulator Accumulation Statement

See "Declaration and Assignment Statements"

lAccumAccumStmt

Local Accumulator Accumulation Statement

See "Declaration and Assignment Statements"/

attrAccumStmt

Attribute Accumulation Statement

See "Declaration and Assignment Statements"

vAccumFuncCall

Vertex-attached Accumulator Function Call Statement

See "Declaration and Assignment Statements"

localVarDeclStmt

Local Variable Declaration Statement

See "SELECT Statement"

insertStmt

INSERT INTO Statement

See "Control Flow Statements"

DMLSubDeleteStmt

DML-sub DELETE Statement

See "Data Modification Statements"

DMLSubcaseStmt

DML-sub CASE statement

See "Data Modification Statements"

DMLSubIfStmt

DML-sub IF statement

See "Data Modification Statements"

DMLSubForEachStmt

DML-sub FOREACH statement

See "Data Modification Statements"

DMLSubWhileStmt

DML-sub WHILE statement

See "Data Modification Statements"

logStmt

LOG Statement

See "Output Statements"

INTERPRET QUERY

INTERPRET QUERY runs a query by translating it line-by-line. This is in contrast to the 2-step flow to install a query first and then run the query.

INTERPRET QUERY runs a query immediately but may take longer to finish than running an installed query. INTERPRET QUERY also has limitations and does not support all GSQL query language features.

There are two GSQL syntax options for Interpreted GSQL:

Interpret an anonymous query

Syntax for interpreting an anonymous query
interpretQuery := INTERPRET QUERY "(" ")"
               [FOR GRAPH graph_name]
               [SYNTAX syntax_name]
               "{" queryBody "}"

This syntax is similar in concept to SQL queries. Queries are not named, do not accept parameters, and are not saved after being run.

Compare the example below to the example in the Create Query section:

  • No query name, no parameters, no RETURN statement.

  • Because no parameter is allowed, the parameter uid is set within the query.

Example of Immediate Mode for INTERPRET QUERY
INTERPRET QUERY () FOR GRAPH Social_Net {
    // declaration statements
    STRING uid = "Jane.Doe";
    users = {Person.*};
    // body statements
    posts = SELECT p
        FROM users:u-(Posted>)-:p
        WHERE u.id == uid;
    PRINT posts, posts.size();
}

Interpret a created query

Syntax for interpreting a created query
runQuery := (RUN | INTERPRET) QUERY [runOptions] queryName "(" parameterValueList ")"

This syntax is like RUN query, except

  • The keyword RUN is replaced with INTERPRET.

  • Some options may not be supported.

Example of Interpret-Only Mode for INTERPRET QUERY
INTERPRET QUERY createQueryEx ("Jane.Doe")

INSTALL QUERY

installQuery := INSTALL QUERY [installOptions] ( "*" | ALL | queryName ["," queryMame]* )

INSTALL QUERY installs a query or multiple queries on a graph.Installing a query compiles the procedures described by the query as well as generates a REST endpoint for running the query.

Installing a query allows the query to be run through the RUN QUERY command as well as through its REST endpoint, both offering stronger performance as compared to running the query through the INTERPRET QUERY command.The INSTALL QUERY command will install the queries specified, with query names separated by a comma.

If a query calls a subquery, the query can only be installed after one of the following conditions is met:

  • The subquery has already been installed

  • The subquery is being installed in the same INSTALL QUERY command as the query itself

If a subquery that was previously installed is dropped from the graph, all installed queries that call the subquery will be disabled. To re-enable a disabled query, all its subqueries need to be installed with the same parameters and return type.

When a single INSTALL QUERY command installs multiple queries, each query is installed independently. If one query fails to be installed, it will not affect the installation of other queries.

To install a query, the user needs to have the WRITE_QUERY privilege on the graph where the query is to be installed or on the global scope.

Users can also install all uninstalled queries on a graph with INSTALL QUERY, using either of the following commands:

  • INSTALL QUERY *

  • INSTALL QUERY ALL

Installing takes several seconds for each query. The current version does not support concurrent installation and running of queries. Other concurrent graph operations will be delayed until the installation finishes.

Concurrent INSTALL QUERY commands are allowed as long as only one INSTALL QUERY command is running on a single graph. Concurrent INSTALL QUERY commands are not allowed on a single graph.

Options for INSTALL QUERY

The following options are available:

Option Effect

-FORCE

Reinstall the query even if the system indicates the query is already installed. This is useful for overwriting an installation that is corrupted or otherwise outdated, without having to drop and then recreate the query. If this option is not used, the GSQL shell will refuse to re-install a query that is already installed.

-SINGLE

Enables a new internal framework for compiling non-distributed queries. Equivalent to the single_gpr session parameter described on the Session Parameters page.

The loop variable in a FOREACH loop with this option enabled is treated as a copy, while normally, changes to the loop variable will change the value in the set or bag expression.

Optimize installed queries

INSTALL QUERY -OPTIMIZE

This feature is deprecated and support for it will be dropped in a future version.

Users can run INSTALL QUERY -OPTIMIZE to optimize all installed queries. The names of the individual queries are not needed. This operation optimizes all previously installed queries, reducing their run times by about 20%. Optimize a query if query run time is more important to you than query installation time.

RUN QUERY

The RUN QUERY command runs an installed query. To run a query with the RUN QUERY command, specify the query name, followed by the query parameters enclosed in parentheses. Running a query executes all statements in the query body and produces output as specified by the output statements in the query.

You can also run an installed query through REST requests - see Run an installed query.

Syntax

RUN QUERY syntax
runQuery := (RUN | INTERPRET) QUERY [runOptions] queryName
    "(" parameterValueList | parameterValueJSON ")"

runOptions := ( "-av" | "-d" )*
parameterValueList := parameterValue ["," parameterValue]*
parmeterValueJSON ::= '{"'parameterName'":' parameterValue(', "'parameterName'":' parameterValue)* '}'

Query parameters

There are two ways of passing parameters to a query in a RUN QUERY command:

Parameter list

To pass parameters to a query with a list, the parameters must be put in the same order as they were in the query definition. Each value passed in will correspond to the parameter at the same index when the query was created.

To use the default value for a parameter, use the _ character for the value of the parameter. You can also omit parameters to use their default value. However, if you omit one parameter, you also have to omit all parameters that come after that parameter.

For example, if we have the following query definition:

CREATE QUERY greet_person(INT age = 3, STRING name = "John",
  DATETIME birthday = to_datetime("2019-02-19 19:19:19"))
{
  PRINT age, name, birthday;
}

To run the query with default values for the parameter name, use _ in the place of the second parameter value:

GSQL > RUN QUERY greet_person (21, _, "2020-02-02 20:02:20")
{
  "error": false,
  "message": "",
  "version": {
    "schema": 0,
    "edition": "enterprise",
    "api": "v2"
  },
  "results": [{
    "birthday": "2020-02-02 20:02:20",
    "name": "John",
    "age": 21
  }]
}

To use the default values for both the second and the third parameters, you can omit both parameters and only provide a value for the first parameter.

GSQL > RUN QUERY greet_person(21)
{
  "error": false,
  "message": "",
  "version": {
    "schema": 0,
    "edition": "enterprise",
    "api": "v2"
  },
  "results": [{
    "birthday": "2019-02-19 19:19:19",
    "name": "John",
    "age": 21
  }]
}

Parameter JSON object

To pass query parameters by name with a JSON object, map the parameter names to their values in a JSON object enclosed in parentheses. Parameters that are not named in the JSON object will keep their default values for the execution of the query.

For example, if we have the following query:

CREATE QUERY greet_person(INT age = 3, STRING name = "John",
  DATETIME birthday = to_datetime("2019-02-19 19:19:19"))
{
  PRINT age, name, birthday;
}

Supplying the parameters with a JSON object will look like the following. The parameter birthday is not named in the parameter JSON object and therefore takes the default value:

RUN QUERY greet_person( {"name": "Emma", "age": 21} )

Complex type parameter passing

This subsection describes how to format the complex type parameter values when executing a query by RUN QUERY. More details about all parameter types are described in Section "Query Parameter Types".

Parameter list

Parameter type Syntax Example

DATETIME

Use a string formatted as "YYYY-MM-DD HH-MM-SS"

"2019-02-19 19:19:19"

Set or bag of primitives

Use square brackets to enclose the collection of values.

A set of integers: [1,5,10]

VERTEX<type>

If the vertex type is specified in the query definition, then the vertex argument is vertex_id

The vertex type is person and the desired ID is person2. "person2"

VERTEX(type not pre-specified)

If the type is not defined in the query definition, then the argument must provide both the id and type in parentheses:*(vertex_id, vertex_type)*

A vertex with ID "person1" and type="person: ("person1","person")

Set or bag of VERTEX<type>

Same as a SET or BAG of primitives, where the primitive type is vertex_id.

[ "person3", "person4" ]

Set or bag of VERTEX(type not pre-specified)

Same as a SET or BAG of vertices, with vertex type not pre-specified. Square brackets enclose a comma-separated list of vertex (id, type) pairs. Mixed types are permitted.

[ ("person1","person"),("11","post") ]

Parameter JSON object

Parameter type Syntax Example

DATETIME

Use a string formatted as "YYYY-MM-DD HH-MM-SS"

"2019-02-19 19:19:19"

Set or bag of primitives

Use a JSON array containing the primitive values

["a", "list", "of", "args"]

VERTEX<type>

Since the type is already specified in the query, you only need to use a JSON object containing the field "id" for the vertex ID

{"id": "person1"}

VERTEX (type not specified)

Use a JSON object containing a field "id" for the vertex ID and a field "type" for the type of the vertex.

{"id": "person1","type": "person"}

Set or bag of VERTEX<type>

Use a JSON array containing a list of JSON VERTEX<type> object

[{"id": "person1"}, {"id": "person2"}]

Options

All-vertex mode -av option

Some queries run with all or almost all vertices in a SELECT statement s, e.g. PageRank algorithm. In this case, the graph processing engine can run much more efficiently in all-vertex mode. In the all-vertex mode, all vertices are always selected, and the following actions become ineffective:

  • Filtering with selected vertices or vertex types. The source vertex set must be all vertices.

  • Filtering with the WHERE clause.

  • Filtering with the HAVING clause.

  • Assigning designated vertex or designated type of vertexes. E.g. X = { vertex_type .*}

To run the query in all-vertex mode, use the -av option in shell mode or include __GQUERY__USING_ALL_ACTIVE_MODE=true in the query string of an HTTP request.

GSQL > RUN QUERY -av test()

## In a curl URL call.  Note the use of both single and double underscores.
curl -X GET 'http://localhost:9000/query/graphname/queryname?__GQUERY__USING_ALL_ACTIVE_MODE=true'

Detached mode -async option

Typically, the GSQL RUN QUERY command runs in the foreground and does not produce output until the query completes, which is inconvenient in the case of long-running queries. Starting with TigerGraph 3.1, you can run queries in Detached Mode to enable background execution of long-running queries.

Queries executed in Detached mode are still subject to the system timeout limit. The default timeout limit is 16 seconds and can be set using the GSQL-TIMEOUT header.

To run a query in Detached Mode from the command line, use the-asyncoption for theRUN QUERYcommand:

GSQL > RUN QUERY -async <queryName>

You will receive a JSON response immediately containing a query ID (request_id):

{
  "error": false,
  "message": "The query is successfully submitted. Please check query status using the request id.",
  "request_id": "<RequestID>"
}

To run queries in Detached Mode via RESTPP endpoint call, use the GSQL-ASYNC header and set its value to true. If the query takes parameters, put them in the query string:

$ curl -s -H "GSQL-ASYNC:true" GET "http://localhost:9000/query/<graphName>/<queryName>?parameter1=<parameter1>

To check the status and results of the queries executed in Detached Mode, use the /query_status and the /query_result RESTPP endpoints.

GSQL Query output format

The standard output of GSQL queries is in industry-standard JSON format. A JSON object is an unordered set of key-value pairs, enclosed in curly braces. Among the acceptable data types for a JSON value are array and object. A JSON array is an ordered list of values, enclosed in square brackets. Since values can be objects or arrays, JSON supports hierarchical, nested structures. Strings are enclosed in double quotation marks. We also use the term field to refer to a key (or a key-value pair) of a given object.

At the top level of the JSON structure are four required fields ("version", "error", "message", and "results") and one dependent field ("code"). If a query is successful, the value of "error" will be "false", the "message" value will be empty, and the "results" value will be the intended output of the query. If an error or exception occurred during query execution, the "error" value will be "true", the "message" value will be a string message describing the error condition, and the "results" field will be empty. Also, the "code" field will contain an error code.

Beginning with version 2 (v2) of the output specification, an additional top-level field is required: "version". The "version" value is an object with the following fields:

Field Description

api

String specifying the output API version. Values are specified as follows:v1'': Output API used in TigerGraph platform v0.8 through v1.0. NOTE: v1'' support is no longer available as of TigerGraph v3.0.”v2” (default): Output API introduced in TigerGraph platform v1.1 This is the latest API.

edition

String indicating the edition of the product.

schema

Integer representing which version of the user’s graph schema is currently in use. When a CREATE GRAPH statement is executed, the version is initialized to 0. Each time a SCHEMA_CHANGE JOB is run, the schema value is incremented by 1 (e.g., 1, 2, etc.)

Other top-level objects, such as "code" may appear in certain circumstances. Note that the top-level objects are enclosed in curly braces, meaning that they form an unordered set. They may appear in any order.

Below is an example of the output of a successful query:

Top Level JSON of a Valid Query - Example
{
  "version": {"edition": "developer","api": "v2","schema": "1"},
  "error": false,
  "message": "",
  "results": [
    {results_of_PRINT_statement_1},
    ...,
    {results_of_PRINT_statement_N}
  ]
}

The value of the "results" key-value pair is a sequential list of the data objects specified by the PRINT statements of the query. The list order follows the order of PRINT execution. The detailed format of the PRINT statement results is described in Output Statements and FILE Objects.

The following REST response misspells the name of the endpoint

GET echo/ Request and Response
curl -X GET "http://localhost:9000/eco"

and generates the following output:

{
  "version": {"edition":"developer","api":"v2","schema":0},
  "error": true,
  "message": "Endpoint is not found from url = /eco, please use GET /endpoints to list all valid endpoints.",
  "code": "REST-1000"
}

Changing the default output API

The following GSQL statement can be used to set the JSON output API configuration.

SET json_api = <version_string>
The only supported JSON API is "v2".

This statement sets a persistent system parameter. Each version of the TigerGraph platform is pre-configured to what was the latest output API that at the time of release.

SHOW QUERY

showQuery := SHOW QUERY queryName

To show the GSQL text of a query, run SHOW QUERY query_name . The query_name argument can use * or ? wildcards from Linux globbing, or it can be a regular expression when preceded by -r. See SHOW: View Parts of the Catalog

Additionally, the ls GSQL command lists all created queries and identifies which queries have been installed.

DROP QUERY

dropQuery := DROP QUERY ( "*" | ALL | queryName ["," queryName]* )

To drop a query, run DROP QUERY query_name __. The query will be uninstalled (if it has been installed) and removed from the dictionary. The GSQL language will refuse to drop an installed query if another query is installed which calls query Q. That is, all calling queries must be dropped before or at the same time that their called subqueries are dropped.

To drop all queries, either of the following commands can be used:

  • DROP QUERY ALL

  • DROP QUERY *

The scope of the command depends on the user’s current scope. If the user has set a working graph, then DROP ALL removes all the queries for that graph. If a user has set their scope to be global, then DROP ALL removes all queries across all graph spaces.