DQL: Tips and Tricks

Get Sample Data

Use the has function to get some sample nodes.

Query

{
  result(func: has(director.film), first: 10) {
    uid
    expand(_all_)
  }
}

Go

package main

import (
    "context"
    "encoding/json"
    "fmt"
    "log"

    "google.golang.org/grpc"
    "github.com/dgraph-io/dgo/v230"
    "github.com/dgraph-io/dgo/v230/protos/api"
)

func main() {
    conn, err := grpc.Dial("localhost:9080", grpc.WithInsecure())
    if err != nil {
        log.Fatal(err)
    }
    defer conn.Close()

    dgraphClient := dgo.NewDgraphClient(api.NewDgraphClient(conn))
    ctx := context.Background()

    txn := dgraphClient.NewTxn()
    defer txn.Discard(ctx)

    query := `{
  result(func: has(director.film), first: 10) {
    uid
    expand(_all_)
  }
}`
    
    resp, err := txn.Query(ctx, query)
    if err != nil {
        log.Fatal(err)
    }

    var result map[string]interface{}
    json.Unmarshal(resp.Json, &result)
    fmt.Printf("%+v\n", result)
}

Java

import io.dgraph.DgraphClient;
import io.dgraph.DgraphGrpc;
import io.dgraph.DgraphProto;
import io.dgraph.Transaction;

import java.util.Map;

public class App {
    public static void main(String[] args) {
        ManagedChannel channel = ManagedChannelBuilder
            .forAddress("localhost", 9080)
            .usePlaintext()
            .build();
        
        DgraphGrpc.DgraphStub stub = DgraphGrpc.newStub(channel);
        DgraphClient dgraphClient = new DgraphClient(stub);
        
        String query = "{
  result(func: has(director.film), first: 10) {
    uid
    expand(_all_)
  }
}";
        
        Transaction txn = dgraphClient.newTransaction();
        try {
            DgraphProto.Response response = txn.query(query);
            System.out.println(response.getJson().toStringUtf8());
        } finally {
            txn.discard();
        }
    }
}

Python

import grpc
from dgraph import DgraphClient, Txn

def main():
    client_stub = DgraphClient("localhost:9080")
    client = DgraphClient(client_stub)
    
    query = """{
  result(func: has(director.film), first: 10) {
    uid
    expand(_all_)
  }
}"""
    
    txn = client.txn()
    try:
        response = txn.query(query)
        print(response.json)
    finally:
        txn.discard()

if __name__ == "__main__":
    main()

JavaScript (gRPC)

const dgraph = require("dgraph-js");
const grpc = require("grpc");

async function main() {
    const clientStub = new dgraph.DgraphClientStub(
        "localhost:9080",
        grpc.credentials.createInsecure()
    );
    const dgraphClient = new dgraph.DgraphClient(clientStub);
    
    const query = `{
  result(func: has(director.film), first: 10) {
    uid
    expand(_all_)
  }
}`;
    
    const txn = dgraphClient.newTxn();
    try {
        const res = await txn.query(query);
        const json = res.getJson();
        console.log(JSON.stringify(JSON.parse(json), null, 2));
    } finally {
        await txn.discard();
    }
}

main().catch((e) => {
    console.error(e);
});

JavaScript (HTTP)

const fetch = require("node-fetch");

async function main() {
    const query = `{
  result(func: has(director.film), first: 10) {
    uid
    expand(_all_)
  }
}`;
    
    const response = await fetch("http://localhost:8080/query", {
        method: "POST",
        headers: {
            "Content-Type": "application/dql"
        },
        body: query
    });
    
    const result = await response.json();
    console.log(JSON.stringify(result, null, 2));
}

main().catch((e) => {
    console.error(e);
});

Curl

curl -X POST http://localhost:8080/query \
  -H "Content-Type: application/dql" \
  -d '{
  result(func: has(director.film), first: 10) {
    uid
    expand(_all_)
  }
}'

Count number of connecting nodes

Use expand(_all_) to expand the nodes' edges, then assign them to a variable. The variable can now be used to iterate over the unique neighboring nodes. Then use count(uid) to count the number of nodes in a block.

Query

{
  uids(func: has(director.film), first: 1) {
    uid
    expand(_all_) { u as uid }
  }

  result(func: uid(u)) {
    count(uid)
  }
}

Go

package main

import (
    "context"
    "encoding/json"
    "fmt"
    "log"

    "google.golang.org/grpc"
    "github.com/dgraph-io/dgo/v230"
    "github.com/dgraph-io/dgo/v230/protos/api"
)

func main() {
    conn, err := grpc.Dial("localhost:9080", grpc.WithInsecure())
    if err != nil {
        log.Fatal(err)
    }
    defer conn.Close()

    dgraphClient := dgo.NewDgraphClient(api.NewDgraphClient(conn))
    ctx := context.Background()

    txn := dgraphClient.NewTxn()
    defer txn.Discard(ctx)

    query := `{
  uids(func: has(director.film), first: 1) {
    uid
    expand(_all_) { u as uid }
  }

  result(func: uid(u)) {
    count(uid)
  }
}`
    
    resp, err := txn.Query(ctx, query)
    if err != nil {
        log.Fatal(err)
    }

    var result map[string]interface{}
    json.Unmarshal(resp.Json, &result)
    fmt.Printf("%+v\n", result)
}

Java

import io.dgraph.DgraphClient;
import io.dgraph.DgraphGrpc;
import io.dgraph.DgraphProto;
import io.dgraph.Transaction;

import java.util.Map;

public class App {
    public static void main(String[] args) {
        ManagedChannel channel = ManagedChannelBuilder
            .forAddress("localhost", 9080)
            .usePlaintext()
            .build();
        
        DgraphGrpc.DgraphStub stub = DgraphGrpc.newStub(channel);
        DgraphClient dgraphClient = new DgraphClient(stub);
        
        String query = "{
  uids(func: has(director.film), first: 1) {
    uid
    expand(_all_) { u as uid }
  }

  result(func: uid(u)) {
    count(uid)
  }
}";
        
        Transaction txn = dgraphClient.newTransaction();
        try {
            DgraphProto.Response response = txn.query(query);
            System.out.println(response.getJson().toStringUtf8());
        } finally {
            txn.discard();
        }
    }
}

Python

import grpc
from dgraph import DgraphClient, Txn

def main():
    client_stub = DgraphClient("localhost:9080")
    client = DgraphClient(client_stub)
    
    query = """{
  uids(func: has(director.film), first: 1) {
    uid
    expand(_all_) { u as uid }
  }

  result(func: uid(u)) {
    count(uid)
  }
}"""
    
    txn = client.txn()
    try:
        response = txn.query(query)
        print(response.json)
    finally:
        txn.discard()

if __name__ == "__main__":
    main()

JavaScript (gRPC)

const dgraph = require("dgraph-js");
const grpc = require("grpc");

async function main() {
    const clientStub = new dgraph.DgraphClientStub(
        "localhost:9080",
        grpc.credentials.createInsecure()
    );
    const dgraphClient = new dgraph.DgraphClient(clientStub);
    
    const query = `{
  uids(func: has(director.film), first: 1) {
    uid
    expand(_all_) { u as uid }
  }

  result(func: uid(u)) {
    count(uid)
  }
}`;
    
    const txn = dgraphClient.newTxn();
    try {
        const res = await txn.query(query);
        const json = res.getJson();
        console.log(JSON.stringify(JSON.parse(json), null, 2));
    } finally {
        await txn.discard();
    }
}

main().catch((e) => {
    console.error(e);
});

JavaScript (HTTP)

const fetch = require("node-fetch");

async function main() {
    const query = `{
  uids(func: has(director.film), first: 1) {
    uid
    expand(_all_) { u as uid }
  }

  result(func: uid(u)) {
    count(uid)
  }
}`;
    
    const response = await fetch("http://localhost:8080/query", {
        method: "POST",
        headers: {
            "Content-Type": "application/dql"
        },
        body: query
    });
    
    const result = await response.json();
    console.log(JSON.stringify(result, null, 2));
}

main().catch((e) => {
    console.error(e);
});

Curl

curl -X POST http://localhost:8080/query \
  -H "Content-Type: application/dql" \
  -d '{
  uids(func: has(director.film), first: 1) {
    uid
    expand(_all_) { u as uid }
  }

  result(func: uid(u)) {
    count(uid)
  }
}'

Search on non-indexed predicates

Use the has function among the value variables to search on non-indexed predicates.

Query

{
  var(func: has(festival.date_founded)) {
    p as festival.date_founded
  }
  query(func: eq(val(p), "1961-01-01T00:00:00Z")) {
      uid
      name@en
      name@ru
      name@pl
      festival.date_founded
      festival.focus { name@en }
      festival.individual_festivals { total : count(uid) }
  }
}

Go

package main

import (
    "context"
    "encoding/json"
    "fmt"
    "log"

    "google.golang.org/grpc"
    "github.com/dgraph-io/dgo/v230"
    "github.com/dgraph-io/dgo/v230/protos/api"
)

func main() {
    conn, err := grpc.Dial("localhost:9080", grpc.WithInsecure())
    if err != nil {
        log.Fatal(err)
    }
    defer conn.Close()

    dgraphClient := dgo.NewDgraphClient(api.NewDgraphClient(conn))
    ctx := context.Background()

    txn := dgraphClient.NewTxn()
    defer txn.Discard(ctx)

    query := `{
  var(func: has(festival.date_founded)) {
    p as festival.date_founded
  }
  query(func: eq(val(p), "1961-01-01T00:00:00Z")) {
      uid
      name@en
      name@ru
      name@pl
      festival.date_founded
      festival.focus { name@en }
      festival.individual_festivals { total : count(uid) }
  }
}`
    
    resp, err := txn.Query(ctx, query)
    if err != nil {
        log.Fatal(err)
    }

    var result map[string]interface{}
    json.Unmarshal(resp.Json, &result)
    fmt.Printf("%+v\n", result)
}

Java

import io.dgraph.DgraphClient;
import io.dgraph.DgraphGrpc;
import io.dgraph.DgraphProto;
import io.dgraph.Transaction;

import java.util.Map;

public class App {
    public static void main(String[] args) {
        ManagedChannel channel = ManagedChannelBuilder
            .forAddress("localhost", 9080)
            .usePlaintext()
            .build();
        
        DgraphGrpc.DgraphStub stub = DgraphGrpc.newStub(channel);
        DgraphClient dgraphClient = new DgraphClient(stub);
        
        String query = "{
  var(func: has(festival.date_founded)) {
    p as festival.date_founded
  }
  query(func: eq(val(p), \"1961-01-01T00:00:00Z\")) {
      uid
      name@en
      name@ru
      name@pl
      festival.date_founded
      festival.focus { name@en }
      festival.individual_festivals { total : count(uid) }
  }
}";
        
        Transaction txn = dgraphClient.newTransaction();
        try {
            DgraphProto.Response response = txn.query(query);
            System.out.println(response.getJson().toStringUtf8());
        } finally {
            txn.discard();
        }
    }
}

Python

import grpc
from dgraph import DgraphClient, Txn

def main():
    client_stub = DgraphClient("localhost:9080")
    client = DgraphClient(client_stub)
    
    query = """{
  var(func: has(festival.date_founded)) {
    p as festival.date_founded
  }
  query(func: eq(val(p), "1961-01-01T00:00:00Z")) {
      uid
      name@en
      name@ru
      name@pl
      festival.date_founded
      festival.focus { name@en }
      festival.individual_festivals { total : count(uid) }
  }
}"""
    
    txn = client.txn()
    try:
        response = txn.query(query)
        print(response.json)
    finally:
        txn.discard()

if __name__ == "__main__":
    main()

JavaScript (gRPC)

const dgraph = require("dgraph-js");
const grpc = require("grpc");

async function main() {
    const clientStub = new dgraph.DgraphClientStub(
        "localhost:9080",
        grpc.credentials.createInsecure()
    );
    const dgraphClient = new dgraph.DgraphClient(clientStub);
    
    const query = `{
  var(func: has(festival.date_founded)) {
    p as festival.date_founded
  }
  query(func: eq(val(p), "1961-01-01T00:00:00Z")) {
      uid
      name@en
      name@ru
      name@pl
      festival.date_founded
      festival.focus { name@en }
      festival.individual_festivals { total : count(uid) }
  }
}`;
    
    const txn = dgraphClient.newTxn();
    try {
        const res = await txn.query(query);
        const json = res.getJson();
        console.log(JSON.stringify(JSON.parse(json), null, 2));
    } finally {
        await txn.discard();
    }
}

main().catch((e) => {
    console.error(e);
});

JavaScript (HTTP)

const fetch = require("node-fetch");

async function main() {
    const query = `{
  var(func: has(festival.date_founded)) {
    p as festival.date_founded
  }
  query(func: eq(val(p), "1961-01-01T00:00:00Z")) {
      uid
      name@en
      name@ru
      name@pl
      festival.date_founded
      festival.focus { name@en }
      festival.individual_festivals { total : count(uid) }
  }
}`;
    
    const response = await fetch("http://localhost:8080/query", {
        method: "POST",
        headers: {
            "Content-Type": "application/dql"
        },
        body: query
    });
    
    const result = await response.json();
    console.log(JSON.stringify(result, null, 2));
}

main().catch((e) => {
    console.error(e);
});

Curl

curl -X POST http://localhost:8080/query \
  -H "Content-Type: application/dql" \
  -d '{
  var(func: has(festival.date_founded)) {
    p as festival.date_founded
  }
  query(func: eq(val(p), "1961-01-01T00:00:00Z")) {
      uid
      name@en
      name@ru
      name@pl
      festival.date_founded
      festival.focus { name@en }
      festival.individual_festivals { total : count(uid) }
  }
}'

Sort edge by nested node values

Dgraph sorting is based on a single level of the subgraph. To sort a level by the values of a deeper level, use query variables to bring nested values up to the level of the edge to be sorted.

Example: Get all actors from a Steven Spielberg movie sorted alphabetically. The actor's name is not accessed from a single traversal from the starring edge; the name is accessible via performance.actor.

Query

{
  spielbergMovies as var(func: allofterms(name@en, "steven spielberg")) {
    name@en
    director.film (orderasc: name@en, first: 1) {
      starring {
        performance.actor {
          ActorName as name@en
        }
        # Stars is a uid-to-value map mapping
        # starring edges to performance.actor names
        Stars as min(val(ActorName))
      }
    }
  }

  movies(func: uid(spielbergMovies)) @cascade {
    name@en
    director.film (orderasc: name@en, first: 1) {
      name@en
      starring (orderasc: val(Stars)) {
        performance.actor {
          name@en
        }
      }
    }
  }
}

Go

package main

import (
    "context"
    "encoding/json"
    "fmt"
    "log"

    "google.golang.org/grpc"
    "github.com/dgraph-io/dgo/v230"
    "github.com/dgraph-io/dgo/v230/protos/api"
)

func main() {
    conn, err := grpc.Dial("localhost:9080", grpc.WithInsecure())
    if err != nil {
        log.Fatal(err)
    }
    defer conn.Close()

    dgraphClient := dgo.NewDgraphClient(api.NewDgraphClient(conn))
    ctx := context.Background()

    txn := dgraphClient.NewTxn()
    defer txn.Discard(ctx)

    query := `{
  spielbergMovies as var(func: allofterms(name@en, "steven spielberg")) {
    name@en
    director.film (orderasc: name@en, first: 1) {
      starring {
        performance.actor {
          ActorName as name@en
        }
        # Stars is a uid-to-value map mapping
        # starring edges to performance.actor names
        Stars as min(val(ActorName))
      }
    }
  }

  movies(func: uid(spielbergMovies)) @cascade {
    name@en
    director.film (orderasc: name@en, first: 1) {
      name@en
      starring (orderasc: val(Stars)) {
        performance.actor {
          name@en
        }
      }
    }
  }
}`
    
    resp, err := txn.Query(ctx, query)
    if err != nil {
        log.Fatal(err)
    }

    var result map[string]interface{}
    json.Unmarshal(resp.Json, &result)
    fmt.Printf("%+v\n", result)
}

Java

import io.dgraph.DgraphClient;
import io.dgraph.DgraphGrpc;
import io.dgraph.DgraphProto;
import io.dgraph.Transaction;

import java.util.Map;

public class App {
    public static void main(String[] args) {
        ManagedChannel channel = ManagedChannelBuilder
            .forAddress("localhost", 9080)
            .usePlaintext()
            .build();
        
        DgraphGrpc.DgraphStub stub = DgraphGrpc.newStub(channel);
        DgraphClient dgraphClient = new DgraphClient(stub);
        
        String query = "{
  spielbergMovies as var(func: allofterms(name@en, \"steven spielberg\")) {
    name@en
    director.film (orderasc: name@en, first: 1) {
      starring {
        performance.actor {
          ActorName as name@en
        }
        # Stars is a uid-to-value map mapping
        # starring edges to performance.actor names
        Stars as min(val(ActorName))
      }
    }
  }

  movies(func: uid(spielbergMovies)) @cascade {
    name@en
    director.film (orderasc: name@en, first: 1) {
      name@en
      starring (orderasc: val(Stars)) {
        performance.actor {
          name@en
        }
      }
    }
  }
}";
        
        Transaction txn = dgraphClient.newTransaction();
        try {
            DgraphProto.Response response = txn.query(query);
            System.out.println(response.getJson().toStringUtf8());
        } finally {
            txn.discard();
        }
    }
}

Python

import grpc
from dgraph import DgraphClient, Txn

def main():
    client_stub = DgraphClient("localhost:9080")
    client = DgraphClient(client_stub)
    
    query = """{
  spielbergMovies as var(func: allofterms(name@en, "steven spielberg")) {
    name@en
    director.film (orderasc: name@en, first: 1) {
      starring {
        performance.actor {
          ActorName as name@en
        }
        # Stars is a uid-to-value map mapping
        # starring edges to performance.actor names
        Stars as min(val(ActorName))
      }
    }
  }

  movies(func: uid(spielbergMovies)) @cascade {
    name@en
    director.film (orderasc: name@en, first: 1) {
      name@en
      starring (orderasc: val(Stars)) {
        performance.actor {
          name@en
        }
      }
    }
  }
}"""
    
    txn = client.txn()
    try:
        response = txn.query(query)
        print(response.json)
    finally:
        txn.discard()

if __name__ == "__main__":
    main()

JavaScript (gRPC)

const dgraph = require("dgraph-js");
const grpc = require("grpc");

async function main() {
    const clientStub = new dgraph.DgraphClientStub(
        "localhost:9080",
        grpc.credentials.createInsecure()
    );
    const dgraphClient = new dgraph.DgraphClient(clientStub);
    
    const query = `{
  spielbergMovies as var(func: allofterms(name@en, "steven spielberg")) {
    name@en
    director.film (orderasc: name@en, first: 1) {
      starring {
        performance.actor {
          ActorName as name@en
        }
        # Stars is a uid-to-value map mapping
        # starring edges to performance.actor names
        Stars as min(val(ActorName))
      }
    }
  }

  movies(func: uid(spielbergMovies)) @cascade {
    name@en
    director.film (orderasc: name@en, first: 1) {
      name@en
      starring (orderasc: val(Stars)) {
        performance.actor {
          name@en
        }
      }
    }
  }
}`;
    
    const txn = dgraphClient.newTxn();
    try {
        const res = await txn.query(query);
        const json = res.getJson();
        console.log(JSON.stringify(JSON.parse(json), null, 2));
    } finally {
        await txn.discard();
    }
}

main().catch((e) => {
    console.error(e);
});

JavaScript (HTTP)

const fetch = require("node-fetch");

async function main() {
    const query = `{
  spielbergMovies as var(func: allofterms(name@en, "steven spielberg")) {
    name@en
    director.film (orderasc: name@en, first: 1) {
      starring {
        performance.actor {
          ActorName as name@en
        }
        # Stars is a uid-to-value map mapping
        # starring edges to performance.actor names
        Stars as min(val(ActorName))
      }
    }
  }

  movies(func: uid(spielbergMovies)) @cascade {
    name@en
    director.film (orderasc: name@en, first: 1) {
      name@en
      starring (orderasc: val(Stars)) {
        performance.actor {
          name@en
        }
      }
    }
  }
}`;
    
    const response = await fetch("http://localhost:8080/query", {
        method: "POST",
        headers: {
            "Content-Type": "application/dql"
        },
        body: query
    });
    
    const result = await response.json();
    console.log(JSON.stringify(result, null, 2));
}

main().catch((e) => {
    console.error(e);
});

Curl

curl -X POST http://localhost:8080/query \
  -H "Content-Type: application/dql" \
  -d '{
  spielbergMovies as var(func: allofterms(name@en, "steven spielberg")) {
    name@en
    director.film (orderasc: name@en, first: 1) {
      starring {
        performance.actor {
          ActorName as name@en
        }
        # Stars is a uid-to-value map mapping
        # starring edges to performance.actor names
        Stars as min(val(ActorName))
      }
    }
  }

  movies(func: uid(spielbergMovies)) @cascade {
    name@en
    director.film (orderasc: name@en, first: 1) {
      name@en
      starring (orderasc: val(Stars)) {
        performance.actor {
          name@en
        }
      }
    }
  }
}'

Obtain unique results by using variables

To obtain unique results, assign the node's edge to a variable. The variable can now be used to iterate over the unique nodes.

Example: Get all unique genres from all of the movies directed by Steven Spielberg.

Query

{
  var(func: eq(name@en, "Steven Spielberg")) {
    director.film {
      genres as genre
    }
  }

  q(func: uid(genres)) {
    name@.
  }
}

Go

package main

import (
    "context"
    "encoding/json"
    "fmt"
    "log"

    "google.golang.org/grpc"
    "github.com/dgraph-io/dgo/v230"
    "github.com/dgraph-io/dgo/v230/protos/api"
)

func main() {
    conn, err := grpc.Dial("localhost:9080", grpc.WithInsecure())
    if err != nil {
        log.Fatal(err)
    }
    defer conn.Close()

    dgraphClient := dgo.NewDgraphClient(api.NewDgraphClient(conn))
    ctx := context.Background()

    txn := dgraphClient.NewTxn()
    defer txn.Discard(ctx)

    query := `{
  var(func: eq(name@en, "Steven Spielberg")) {
    director.film {
      genres as genre
    }
  }

  q(func: uid(genres)) {
    name@.
  }
}`
    
    resp, err := txn.Query(ctx, query)
    if err != nil {
        log.Fatal(err)
    }

    var result map[string]interface{}
    json.Unmarshal(resp.Json, &result)
    fmt.Printf("%+v\n", result)
}

Java

import io.dgraph.DgraphClient;
import io.dgraph.DgraphGrpc;
import io.dgraph.DgraphProto;
import io.dgraph.Transaction;

import java.util.Map;

public class App {
    public static void main(String[] args) {
        ManagedChannel channel = ManagedChannelBuilder
            .forAddress("localhost", 9080)
            .usePlaintext()
            .build();
        
        DgraphGrpc.DgraphStub stub = DgraphGrpc.newStub(channel);
        DgraphClient dgraphClient = new DgraphClient(stub);
        
        String query = "{
  var(func: eq(name@en, \"Steven Spielberg\")) {
    director.film {
      genres as genre
    }
  }

  q(func: uid(genres)) {
    name@.
  }
}";
        
        Transaction txn = dgraphClient.newTransaction();
        try {
            DgraphProto.Response response = txn.query(query);
            System.out.println(response.getJson().toStringUtf8());
        } finally {
            txn.discard();
        }
    }
}

Python

import grpc
from dgraph import DgraphClient, Txn

def main():
    client_stub = DgraphClient("localhost:9080")
    client = DgraphClient(client_stub)
    
    query = """{
  var(func: eq(name@en, "Steven Spielberg")) {
    director.film {
      genres as genre
    }
  }

  q(func: uid(genres)) {
    name@.
  }
}"""
    
    txn = client.txn()
    try:
        response = txn.query(query)
        print(response.json)
    finally:
        txn.discard()

if __name__ == "__main__":
    main()

JavaScript (gRPC)

const dgraph = require("dgraph-js");
const grpc = require("grpc");

async function main() {
    const clientStub = new dgraph.DgraphClientStub(
        "localhost:9080",
        grpc.credentials.createInsecure()
    );
    const dgraphClient = new dgraph.DgraphClient(clientStub);
    
    const query = `{
  var(func: eq(name@en, "Steven Spielberg")) {
    director.film {
      genres as genre
    }
  }

  q(func: uid(genres)) {
    name@.
  }
}`;
    
    const txn = dgraphClient.newTxn();
    try {
        const res = await txn.query(query);
        const json = res.getJson();
        console.log(JSON.stringify(JSON.parse(json), null, 2));
    } finally {
        await txn.discard();
    }
}

main().catch((e) => {
    console.error(e);
});

JavaScript (HTTP)

const fetch = require("node-fetch");

async function main() {
    const query = `{
  var(func: eq(name@en, "Steven Spielberg")) {
    director.film {
      genres as genre
    }
  }

  q(func: uid(genres)) {
    name@.
  }
}`;
    
    const response = await fetch("http://localhost:8080/query", {
        method: "POST",
        headers: {
            "Content-Type": "application/dql"
        },
        body: query
    });
    
    const result = await response.json();
    console.log(JSON.stringify(result, null, 2));
}

main().catch((e) => {
    console.error(e);
});

Curl

curl -X POST http://localhost:8080/query \
  -H "Content-Type: application/dql" \
  -d '{
  var(func: eq(name@en, "Steven Spielberg")) {
    director.film {
      genres as genre
    }
  }

  q(func: uid(genres)) {
    name@.
  }
}'

Usage of checkpwd boolean

Store the result of checkpwd in a query variable and then match it against 1 (checkpwd is true) or 0 (checkpwd is false).

Query

{  
  exampleData(func: has(email)) {
    uid
    email
    check as checkpwd(pass, "1bdfhJHb!fd")
  }
  userMatched(func: eq(val(check), 1)) {
    uid
    email
  }
  userIncorrect(func: eq(val(check), 0)) {
    uid
    email
  }
}

Go

package main

import (
    "context"
    "encoding/json"
    "fmt"
    "log"

    "google.golang.org/grpc"
    "github.com/dgraph-io/dgo/v230"
    "github.com/dgraph-io/dgo/v230/protos/api"
)

func main() {
    conn, err := grpc.Dial("localhost:9080", grpc.WithInsecure())
    if err != nil {
        log.Fatal(err)
    }
    defer conn.Close()

    dgraphClient := dgo.NewDgraphClient(api.NewDgraphClient(conn))
    ctx := context.Background()

    txn := dgraphClient.NewTxn()
    defer txn.Discard(ctx)

    query := `{  
  exampleData(func: has(email)) {
    uid
    email
    check as checkpwd(pass, "1bdfhJHb!fd")
  }
  userMatched(func: eq(val(check), 1)) {
    uid
    email
  }
  userIncorrect(func: eq(val(check), 0)) {
    uid
    email
  }
}`
    
    resp, err := txn.Query(ctx, query)
    if err != nil {
        log.Fatal(err)
    }

    var result map[string]interface{}
    json.Unmarshal(resp.Json, &result)
    fmt.Printf("%+v\n", result)
}

Java

import io.dgraph.DgraphClient;
import io.dgraph.DgraphGrpc;
import io.dgraph.DgraphProto;
import io.dgraph.Transaction;

import java.util.Map;

public class App {
    public static void main(String[] args) {
        ManagedChannel channel = ManagedChannelBuilder
            .forAddress("localhost", 9080)
            .usePlaintext()
            .build();
        
        DgraphGrpc.DgraphStub stub = DgraphGrpc.newStub(channel);
        DgraphClient dgraphClient = new DgraphClient(stub);
        
        String query = "{  
  exampleData(func: has(email)) {
    uid
    email
    check as checkpwd(pass, \"1bdfhJHb!fd\")
  }
  userMatched(func: eq(val(check), 1)) {
    uid
    email
  }
  userIncorrect(func: eq(val(check), 0)) {
    uid
    email
  }
}";
        
        Transaction txn = dgraphClient.newTransaction();
        try {
            DgraphProto.Response response = txn.query(query);
            System.out.println(response.getJson().toStringUtf8());
        } finally {
            txn.discard();
        }
    }
}

Python

import grpc
from dgraph import DgraphClient, Txn

def main():
    client_stub = DgraphClient("localhost:9080")
    client = DgraphClient(client_stub)
    
    query = """{  
  exampleData(func: has(email)) {
    uid
    email
    check as checkpwd(pass, "1bdfhJHb!fd")
  }
  userMatched(func: eq(val(check), 1)) {
    uid
    email
  }
  userIncorrect(func: eq(val(check), 0)) {
    uid
    email
  }
}"""
    
    txn = client.txn()
    try:
        response = txn.query(query)
        print(response.json)
    finally:
        txn.discard()

if __name__ == "__main__":
    main()

JavaScript (gRPC)

const dgraph = require("dgraph-js");
const grpc = require("grpc");

async function main() {
    const clientStub = new dgraph.DgraphClientStub(
        "localhost:9080",
        grpc.credentials.createInsecure()
    );
    const dgraphClient = new dgraph.DgraphClient(clientStub);
    
    const query = `{  
  exampleData(func: has(email)) {
    uid
    email
    check as checkpwd(pass, "1bdfhJHb!fd")
  }
  userMatched(func: eq(val(check), 1)) {
    uid
    email
  }
  userIncorrect(func: eq(val(check), 0)) {
    uid
    email
  }
}`;
    
    const txn = dgraphClient.newTxn();
    try {
        const res = await txn.query(query);
        const json = res.getJson();
        console.log(JSON.stringify(JSON.parse(json), null, 2));
    } finally {
        await txn.discard();
    }
}

main().catch((e) => {
    console.error(e);
});

JavaScript (HTTP)

const fetch = require("node-fetch");

async function main() {
    const query = `{  
  exampleData(func: has(email)) {
    uid
    email
    check as checkpwd(pass, "1bdfhJHb!fd")
  }
  userMatched(func: eq(val(check), 1)) {
    uid
    email
  }
  userIncorrect(func: eq(val(check), 0)) {
    uid
    email
  }
}`;
    
    const response = await fetch("http://localhost:8080/query", {
        method: "POST",
        headers: {
            "Content-Type": "application/dql"
        },
        body: query
    });
    
    const result = await response.json();
    console.log(JSON.stringify(result, null, 2));
}

main().catch((e) => {
    console.error(e);
});

Curl

curl -X POST http://localhost:8080/query \
  -H "Content-Type: application/dql" \
  -d '{  
  exampleData(func: has(email)) {
    uid
    email
    check as checkpwd(pass, "1bdfhJHb!fd")
  }
  userMatched(func: eq(val(check), 1)) {
    uid
    email
  }
  userIncorrect(func: eq(val(check), 0)) {
    uid
    email
  }
}'