Querying with Select and Conditions

The following example shows how to return the name, address.zipCode, age, and phoneNumber fields from documents that have address.zipCode equal to 95196. It uses an OJAI query and condition.

/*
 * Copyright (c) 2018 MapR, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

const { ConnectionManager } = require('node-maprdb');

const connectionString = 'localhost:5678?' +
  'auth=basic;' +
  'user=mapr;' +
  'password=mapr;' +
  'ssl=true;' +
  'sslCA=/opt/mapr/conf/ssl_truststore.pem;' +
  'sslTargetNameOverride=node1.mapr.com';

let connection;

// Create a connection to data access server
ConnectionManager.getConnection(connectionString)
  .then((conn) => {
    connection = conn;
    // Get a store
    return connection.getStore('/demo_table');
  })
  .then((store) => {
    // Create an OJAI query
    const query = {"$select": ["name",
        "adress.zipCode",
        "age",
        "phoneNumbers[0]"],
      "$where": {"$eq": {"address.zipCode": 95196}}};
    // fetch OJAI Documents by query
    return store.find(query);
  })
  .then((queryResult) => {
    queryResult.on('data', (document) => {
      // Print OJAI Documents from document stream
      console.log(document);
    });
    queryResult.on('end', () => {
      // close the OJAI connection
      connection.close();
    });
  });

The following example shows how to return the name, address.zipCode, age, and phoneNumber fields from documents that have address.zipCode equal to 95196. It uses an OJAI query and condition.

from mapr.ojai.storage.ConnectionFactory import ConnectionFactory

# Create a connection to data access server
connection_str = "localhost:5678?auth=basic;user=mapr;password=mapr;" \
          "ssl=true;" \
          "sslCA=/opt/mapr/conf/ssl_truststore.pem;" \
          "sslTargetNameOverride=node1.mapr.com"
connection = ConnectionFactory.get_connection(connection_str=connection_str)

# Get a store and assign it as a DocumentStore object
store = connection.get_store('/demo_table')

# Create an OJAI query
query = {"$select": ["name",
                     "adress.zipCode",
                     "age",
                     "phoneNumbers[0]"],
         "$where": {"$eq": {"address.zipCode": 95196}}}

# options for find request
options = {
    'ojai.mapr.query.result-as-document': True
    }

# fetch OJAI Documents by query
query_result = store.find(query,
                          options=options)

# Print OJAI Documents from document stream
for doc in query_result:
    print(doc.as_dictionary())

# close the OJAI connection
connection.close()

The following two dbshell commands are equivalent to the code examples. See dbshell find or findbyid for more details about the syntax dbshell provides.

find /demo_table --query {
   "$select":["name","address.zipCode","age","phoneNumber[0]"],
   "$where":{"$eq":{"address.zipCode":95196}}
}

find /demo_table 
   --fields name,address.zipCode,age,phoneNumber[0]
   --where {"$eq":{"address.zipCode":95196}}  

The following example shows how to return the name, address.zipCode, age, and phoneNumber fields from documents that have address.zipCode equal to 95196. It uses an OJAI query and condition.

using System;
using MapRDB.Driver;
using MapRDB.Driver.Ojai;

public class FindQueryWithSelectAndCondition
{
	public async void FindQueryWithSelectAndCondition()
	{
        // Create a connection to data access server
        var connectionStr = $"localhost:5678?auth=basic;" +
            $"user=mapr;" +
            $"password=mapr;" +
            $"ssl=true;" +
            $"sslCA=/opt/mapr/conf/ssl_truststore.pem;" +
            $"sslTargetNameOverride=node1.mapr.com";
        var connection = ConnectionFactory.CreateConnection(connectionStr);

        // Get a store and assign it as a DocumentStore object
        var store = connection.GetStore("/demo_table");

        // Create an OJAI condition
        var condition = connection
            .NewQueryCondition()
                .Is("address.zipCode", QueryOp.EQUAL, 95196)
                .Close()
            .Build();

        // Create an OJAI query
        var query = connection
            .NewQuery()
                .Select("name", "adress.zipCode", "age", "phoneNumbers[0]")
                .Where(condition)
            .Build();

        // Fetch OJAI Documents by query
        var queryResult = store.Find(query);

        var documentStream = await queryResult.GetDocumentAsyncStream().GetAllDocuments();
        // Print OJAI Documents from document stream
        foreach (var document in documentStream)
        {
            Console.WriteLine(document.ToJsonString());
        }

        // Close the OJAI connection
        connection.Close();
    }
}

The following example shows how to return the name, address.zipCode, age, and phoneNumber fields from documents that have address.zipCode equal to 95196. It uses an OJAI query and condition.

package main

import (
	"fmt"
	client "github.com/mapr/private-maprdb-go-client"
)

func main() {
	// Create connection string
	connectionString := "192.168.33.11:5678?" +
		"auth=basic;" +
		"user=mapr;" +
		"password=mapr;" +
		"ssl=true;" +
		"sslCA=/opt/mapr/conf/ssl_truststore.pem;" +
		"sslTargetNameOverride=node1.cluster.com"

	storeName := "/demo_table"

	// Create a connection to DAG
	connection, err := client.MakeConnection(connectionString)
	if err != nil {
		panic(err)
	}

	// Get a store and assign it as a DocumentStore struct
	store, err := connection.GetStore(storeName)
	if err != nil {
		panic(err)
	}

	// Options for find request
	options := &client.FindOptions{ResultAsDocument: true}

	// Create an OJAI query
	query := map[string]interface{}{"$select": []interface{}{"firstName", "address.zipCode", "age", "phoneNumbers[0]"},
		"$where": map[string]interface{}{
			"$eq": map[string]interface{}{"address.zipCode": 95196}}}

	// Fetch all OJAI Documents from table
	findResult, err := store.FindQueryMap(query, options)

	// Print OJAI Documents from document stream
	for _, doc := range findResult.DocumentList() {
		fmt.Println(doc)
	}

	// Close connection
	connection.Close()
}