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Querying in React DataManager component

22 Oct 2021 / 10 minutes to read

In this section, you will see in detail about how to build query using Query class and consume the data source.

Specifying resource name using `from`

The from method is used to specify the resource name or table name from where the data should be retrieved.

Source

Preview

App.tsx

rowTemplate.tsx

orders.tsx

import { getValue } from '@syncfusion/ej2-base';
import { DataManager, ODataAdaptor, Query, ReturnOption } from '@syncfusion/ej2-data';
import * as React from 'react';
import { IOrders } from './orders';
import { Row } from './rowTemplate';

const SERVICE_URI: string = 'https://js.syncfusion.com/demos/ejServices/Wcf/Northwind.svc/Orders';

export default class App extends React.Component<{}, {}>{
    constructor(props: object) {
        super(props);
        this.state = { items: [] };
        new DataManager({ url: SERVICE_URI, adaptor: new ODataAdaptor })
            .executeQuery(new Query().take(8))
            .then((e: ReturnOption) => {
                const res = (e.result as IOrders[]).map((row: IOrders) => (<Row {...row}/>));
                this.setState({
                    items: res
                });
            });
     }

    public render() {
        return (<table id='datatable' className='e-table'>
                <thead>
                    <tr><th>Order ID</th><th>Customer ID</th><th>Employee ID</th></tr>
                </thead>
                <tbody>{ getValue('items', this.state) }</tbody>
            </table>)
    }

}

import * as React from 'react';
import { IOrders } from './orders';

export class Row extends React.Component<{}, {}>{
    public render() {
        const item: IOrders = this.props as IOrders; 
        return (<tr>
                 <td>{item.OrderID}</td>
                 <td>{item.CustomerID}</td>
                 <td>{item.EmployeeID}</td>
                </tr>)
    }
}

export interface IOrders {
    OrderID: number; 
    EmployeeID: number; 
    CustomerID: string; 
    Order_Details: object[]; 
}

Projection using select

The select method is used to select particular fields or columns from the data source.

Source

Preview

App.tsx

rowTemplate.tsx

orders.tsx

import { getValue } from '@syncfusion/ej2-base';
import { DataManager, ODataAdaptor, Query, ReturnOption } from '@syncfusion/ej2-data';
import * as React from 'react';
import { IOrders } from './orders';
import { Row } from './rowTemplate';

const SERVICE_URI: string = 'https://js.syncfusion.com/demos/ejServices/Wcf/Northwind.svc/Orders';

export default class App extends React.Component<{}, {}>{
    constructor(props: object) {
        super(props);
        this.state = { items: [] };
        new DataManager({ url: SERVICE_URI, adaptor: new ODataAdaptor })
            .executeQuery(new Query().select(['OrderID', 'CustomerID', 'EmployeeID']).take(8))
            .then((e: ReturnOption) => {
                const res = (e.result as IOrders[]).map((row: IOrders) => (<Row {...row}/>));
                this.setState({
                    items: res
                });
            });
     }

    public render() {
        return (<table id='datatable' className='e-table'>
                <thead>
                    <tr><th>Order ID</th><th>Customer ID</th><th>Employee ID</th></tr>
                </thead>
                <tbody>{ getValue('items', this.state) }</tbody>
            </table>)
    }

}

import * as React from 'react';
import { IOrders } from './orders';

export class Row extends React.Component<{}, {}>{
    public render() {
        const item: IOrders = this.props as IOrders; 
        return (<tr>
                 <td>{item.OrderID}</td>
                 <td>{item.CustomerID}</td>
                 <td>{item.EmployeeID}</td>
                </tr>)
    }
}

export interface IOrders {
    OrderID: number; 
    EmployeeID: number; 
    CustomerID: string; 
    Order_Details: object[]; 
}

You can use the expand method to eagerly load navigation properties. The navigation properties values are accessed using appropriate field names separated by dot(.) sign.

Source

Preview

App.tsx

rowTemplate.tsx

import { getValue } from '@syncfusion/ej2-base';
import { DataManager, ODataAdaptor, Query, ReturnOption } from '@syncfusion/ej2-data';
import * as React from 'react';
import { IOrders } from './orders';
import { Row } from './rowTemplate';

const SERVICE_URI: string = 'https://js.syncfusion.com/demos/ejServices/Wcf/Northwind.svc/Orders';

export default class App extends React.Component<{}, {}>{
    constructor(props: object) {
        super(props);
        this.state = { items: [] };
        new DataManager({ url: SERVICE_URI, adaptor: new ODataAdaptor })
            .executeQuery(new Query()
                .expand('Employee').select(['OrderID', 'CustomerID', 'Employee.FirstName']).take(8))
            .then((e: ReturnOption) => {
                const res = (e.result as IOrders[]).map((row: IOrders) => (<Row {...row}/>));
                this.setState({
                    items: res
                });
            });
     }

    public render() {
        return (<table id='datatable' className='e-table'>
                <thead>
                    <tr><th>Order ID</th><th>Customer ID</th><th>Employee ID</th></tr>
                </thead>
                <tbody>{ getValue('items', this.state) }</tbody>
            </table>)
    }

}

import * as React from 'react';

interface IOrders {OrderID: number, CustomerID: string, Employee: {FirstName: string} };

export class Row extends React.Component<{}, {}>{
    public render() {
        const item: IOrders  = this.props as IOrders; 
        return (<tr>
            <td>{item.OrderID}</td>
            <td>{item.CustomerID}</td>
            <td>{item.Employee.FirstName}</td>
           </tr>)
    }
}

Sorting

You can use the sortBy method to perform sort operation in the data source. Default sorting order is ascending. To change the sort order, either you can specify the second argument of sortBy as descending or use the sortByDesc method.

Source

Preview

App.tsx

rowTemplate.tsx

orders.tsx

import { getValue } from '@syncfusion/ej2-base';
import { DataManager, ODataAdaptor, Query, ReturnOption } from '@syncfusion/ej2-data';
import * as React from 'react';
import { IOrders } from './orders';
import { Row } from './rowTemplate';

const SERVICE_URI: string = 'https://js.syncfusion.com/demos/ejServices/Wcf/Northwind.svc/Orders';

export default class App extends React.Component<{}, {}>{
    constructor(props: object) {
        super(props);
        this.state = { items: [] };
        new DataManager({ url: SERVICE_URI, adaptor: new ODataAdaptor })
            .executeQuery(new Query().sortBy('CustomerID', 'descending').take(8))
            .then((e: ReturnOption) => {
                const res = (e.result as IOrders[]).map((row: IOrders) => (<Row {...row}/>));
                this.setState({
                    items: res
                });
            });
     }

    public render() {
        return (<table id='datatable' className='e-table'>
                <thead>
                    <tr><th>Order ID</th><th>Customer ID</th><th>Employee ID</th></tr>
                </thead>
                <tbody>{ getValue('items', this.state) }</tbody>
            </table>)
    }

}

import * as React from 'react';
import { IOrders } from './orders';

export class Row extends React.Component<{}, {}>{
    public render() {
        const item: IOrders = this.props as IOrders; 
        return (<tr>
                 <td>{item.OrderID}</td>
                 <td>{item.CustomerID}</td>
                 <td>{item.EmployeeID}</td>
                </tr>)
    }
}

export interface IOrders {
    OrderID: number; 
    EmployeeID: number; 
    CustomerID: string; 
    Order_Details: object[]; 
}

Multi sorting can be performed by simply chaining the multiple sortBy methods.

Filtering

You can use the where method to build filter criteria which allows you to get reduced view of records. The where method can also be chained to form multiple filter criteria.

Source

Preview

App.tsx

rowTemplate.tsx

orders.tsx

import { getValue } from '@syncfusion/ej2-base';
import { DataManager, ODataAdaptor, Query, ReturnOption } from '@syncfusion/ej2-data';
import * as React from 'react';
import { IOrders } from './orders';
import { Row } from './rowTemplate';

const SERVICE_URI: string = 'https://js.syncfusion.com/demos/ejServices/Wcf/Northwind.svc/Orders';

export default class App extends React.Component<{}, {}>{
    constructor(props: object) {
        super(props);
        this.state = { items: [] };
        new DataManager({ url: SERVICE_URI, adaptor: new ODataAdaptor })
            .executeQuery(new Query().where('EmployeeID', 'equal', 3).take(8))
            .then((e: ReturnOption) => {
                const res = (e.result as IOrders[]).map((row: IOrders) => (<Row {...row}/>));
                this.setState({
                    items: res
                });
            });
     }

    public render() {
        return (<table id='datatable' className='e-table'>
                <thead>
                    <tr><th>Order ID</th><th>Customer ID</th><th>Employee ID</th></tr>
                </thead>
                <tbody>{ getValue('items', this.state) }</tbody>
            </table>)
    }

}

import * as React from 'react';
import { IOrders } from './orders';

export class Row extends React.Component<{}, {}>{
    public render() {
        const item: IOrders = this.props as IOrders; 
        return (<tr>
                 <td>{item.OrderID}</td>
                 <td>{item.CustomerID}</td>
                 <td>{item.EmployeeID}</td>
                </tr>)
    }
}

export interface IOrders {
    OrderID: number; 
    EmployeeID: number; 
    CustomerID: string; 
    Order_Details: object[]; 
}

Filter Operators

Filter operators are generally used to specify the filter type. The various filter operators supported by DataManager is listed below.

greaterthan
greaterthanorequal
lessthan
lessthanorequal
equal
notequal
startswith
endswith
contains

These filter operators are used for creating filter query using where method and Predicate class.

Build complex filter criteria using `Predicate`

Sometimes chaining where method is not sufficient to create very complex filter criteria, in such cases we can use Predicate class to create composite filter criteria.

Source

Preview

App.tsx

rowTemplate.tsx

orders.tsx

import { getValue } from '@syncfusion/ej2-base';
import { DataManager, ODataAdaptor, Predicate, Query, ReturnOption } from '@syncfusion/ej2-data';
import * as React from 'react';
import { IOrders } from './orders';
import { Row } from './rowTemplate';

const SERVICE_URI: string = 'https://js.syncfusion.com/demos/ejServices/Wcf/Northwind.svc/Orders';

export default class App extends React.Component<{}, {}>{
constructor(props: object) {
    super(props);
    this.state = { items: [] };
    let predicate: Predicate = new Predicate('EmployeeID', 'equal', 3);
    predicate = predicate.or('EmployeeID', 'equal', 2);
    new DataManager({ url: SERVICE_URI, adaptor: new ODataAdaptor })
        .executeQuery(new Query().where(predicate).take(8))
        .then((e: ReturnOption) => {
            const res = (e.result as IOrders[]).map((row: IOrders) => (<Row {...row}/>));
            this.setState({
                items: res
            });
        });
 }

public render() {
    return (<table id='datatable' className='e-table'>
            <thead>
                <tr><th>Order ID</th><th>Customer ID</th><th>Employee ID</th></tr>
            </thead>
            <tbody>{ getValue('items', this.state) }</tbody>
        </table>)
}

}

import * as React from 'react';
import { IOrders } from './orders';

export class Row extends React.Component<{}, {}>{
    public render() {
        const item: IOrders = this.props as IOrders; 
        return (<tr>
                 <td>{item.OrderID}</td>
                 <td>{item.CustomerID}</td>
                 <td>{item.EmployeeID}</td>
                </tr>)
    }
}

export interface IOrders {
    OrderID: number; 
    EmployeeID: number; 
    CustomerID: string; 
    Order_Details: object[]; 
}

Searching

You can use the search method to create search criteria, it differs from the filter in the way that search criteria will applied to all fields in the data source whereas filter criteria will be applied to a particular field.

Source

Preview

App.tsx

rowTemplate.tsx

orders.tsx

import { getValue } from '@syncfusion/ej2-base';
import { DataManager, ODataAdaptor, Predicate, Query, ReturnOption } from '@syncfusion/ej2-data';
import * as React from 'react';
import { IOrders } from './orders';
import { Row } from './rowTemplate';

const SERVICE_URI: string = 'https://js.syncfusion.com/demos/ejServices/Wcf/Northwind.svc/Orders';

export default class App extends React.Component<{}, {}>{
constructor(props: object) {
    super(props);
    this.state = { items: [] };
    let predicate: Predicate = new Predicate('EmployeeID', 'equal', 3);
    predicate = predicate.or('EmployeeID', 'equal', 2);
    new DataManager({ url: SERVICE_URI, adaptor: new ODataAdaptor })
        .executeQuery(new Query().search('VI', ['CustomerID']))
        .then((e: ReturnOption) => {
            const res = (e.result as IOrders[]).map((row: IOrders) => (<Row {...row}/>));
            this.setState({
                items: res
            });
        });
 }

public render() {
    return (<table id='datatable' className='e-table'>
            <thead>
                <tr><th>Order ID</th><th>Customer ID</th><th>Employee ID</th></tr>
            </thead>
            <tbody>{ getValue('items', this.state) }</tbody>
        </table>)
}

}

import * as React from 'react';
import { IOrders } from './orders';

export class Row extends React.Component<{}, {}>{
    public render() {
        const item: IOrders = this.props as IOrders; 
        return (<tr>
                 <td>{item.OrderID}</td>
                 <td>{item.CustomerID}</td>
                 <td>{item.EmployeeID}</td>
                </tr>)
    }
}

export interface IOrders {
    OrderID: number; 
    EmployeeID: number; 
    CustomerID: string; 
    Order_Details: object[]; 
}

You can search particular fields by passing the field name collection in the second argument of search method.

Grouping

DataManager allow you to group records by category. The group method is used to add group query.

Source

Preview

App.tsx

rowTemplate.tsx

groupTemplate.tsx

orders.tsx

import { getValue } from '@syncfusion/ej2-base';
import { DataManager, Group, ODataAdaptor, Query, ReturnOption } from '@syncfusion/ej2-data';
import * as React from 'react';
import { GroupRow } from './groupTemplate';

const SERVICE_URI: string = 'https://js.syncfusion.com/demos/ejServices/Wcf/Northwind.svc/Orders';

export default class App extends React.Component<{}, {}>{
constructor(props: object) {
    super(props);
    this.state = { items: [] };
    new DataManager({ url: SERVICE_URI, adaptor: new ODataAdaptor })
        .executeQuery(new Query().group('CustomerID').take(8))
        .then((e: ReturnOption) => {
            const res = (e.result as Group[]).map((row: Group) => (<GroupRow {...row}/>));
            this.setState({
                items: res
            });
        });
 }

public render() {
    return (<table id='datatable' className='e-table'>
            <thead>
                <tr><th>Order ID</th><th>Customer ID</th><th>Employee ID</th></tr>
            </thead>
            { getValue('items', this.state) }
        </table>)
}

}

import { getValue } from '@syncfusion/ej2-base';
import * as React from 'react';
import { IOrders } from './orders';

export class Row extends React.Component<{}, {}>{
    public render() {
        const item: IOrders = this.props as IOrders; 
        if (getValue('caption', item)) {
            return (<tr>
                <td colSpan={3}>{getValue('caption', item)}</td>
            </tr>)
        }
        return (<tr>
                 <td>{item.OrderID}</td>
                 <td>{item.CustomerID}</td>
                 <td>{item.EmployeeID}</td>
                </tr>)
    }
}

import { Group } from '@syncfusion/ej2-data';
import * as React from 'react';
import { IOrders } from './orders';
import { Row } from './rowTemplate';

export class GroupRow extends React.Component<{}, {}>{
    public getRows(data: object[]) {
        return data.map((row: IOrders) => (<Row {...row}/>));
    }
    public render() {
        const item: Group = this.props as Group; 
        const ag: { caption: string } = { caption: item.field + ' - '
            + (item.items && item.items[0][item.field as string]) };
        return (<tbody> <Row {...ag}/> { this.getRows(item.items as object[]) }</tbody>)
    }
}

export interface IOrders {
    SNO: number,
    OrderID: number; 
    EmployeeID: number; 
    CustomerID: string; 
    Order_Details: object[]; 
}

Multiple grouping can be done by simply chaining the group method.

Paging

You can query paged data using page method. This allow you to query particular set of records based on the page size and index.

Source

Preview

App.tsx

rowTemplate.tsx

orders.tsx

import { getValue } from '@syncfusion/ej2-base';
import { DataManager, ODataAdaptor, Predicate, Query, ReturnOption } from '@syncfusion/ej2-data';
import * as React from 'react';
import { IOrders } from './orders';
import { Row } from './rowTemplate';

const SERVICE_URI: string = 'https://js.syncfusion.com/demos/ejServices/Wcf/Northwind.svc/Orders';

export default class App extends React.Component<{}, {}>{
constructor(props: object) {
    super(props);
    this.state = { items: [] };
    let predicate: Predicate = new Predicate('EmployeeID', 'equal', 3);
    predicate = predicate.or('EmployeeID', 'equal', 2);
    new DataManager({ url: SERVICE_URI, adaptor: new ODataAdaptor })
        .executeQuery(new Query().page(2, 8))
        .then((e: ReturnOption) => {
            const res = (e.result as IOrders[]).map((row: IOrders) => (<Row {...row}/>));
            this.setState({
                items: res
            });
        });
 }

public render() {
    return (<table id='datatable' className='e-table'>
            <thead>
                <tr><th>Order ID</th><th>Customer ID</th><th>Employee ID</th></tr>
            </thead>
            <tbody>{ getValue('items', this.state) }</tbody>
        </table>)
}

}

import * as React from 'react';
import { IOrders } from './orders';

export class Row extends React.Component<{}, {}>{
    public render() {
        const item: IOrders = this.props as IOrders; 
        return (<tr>
                 <td>{item.OrderID}</td>
                 <td>{item.CustomerID}</td>
                 <td>{item.EmployeeID}</td>
                </tr>)
    }
}

export interface IOrders {
    OrderID: number; 
    EmployeeID: number; 
    CustomerID: string; 
    Order_Details: object[]; 
}

Aggregation

The aggregate method allows you to get aggregated value for a field based on the type.

The built-in aggregate types are,

sum
average
min
max
count
truecount
falsecount

Source

Preview

App.tsx

rowTemplate.tsx

aggregateTemplate.tsx

orders.tsx

import { getValue } from '@syncfusion/ej2-base';
import { Aggregates, DataManager, ODataAdaptor, Query, ReturnOption } from '@syncfusion/ej2-data';
import * as React from 'react';
import { AggregateRow } from './aggregateTemplate';
import { IOrders } from './orders';
import { Row } from './rowTemplate';

const SERVICE_URI: string = 'https://js.syncfusion.com/demos/ejServices/Wcf/Northwind.svc/Orders';

export default class App extends React.Component<{}, {}>{
constructor(props: object) {
    super(props);
    this.state = { items: [], aggregates: [] };
    new DataManager({ url: SERVICE_URI, adaptor: new ODataAdaptor })
    .executeQuery(new Query().take(5).requiresCount().aggregate('min', 'EmployeeID'))
        .then((e: ReturnOption) => {
            const agg: { min: object } = { min: (e.aggregates as Aggregates)['EmployeeID - min'] };
            const ret : React.ReactElement = <AggregateRow {...agg}/>;
            const res = (e.result as IOrders[]).map((row: IOrders) => (<Row {...row}/>));
            this.setState({
                aggregates: [ret],
                items: res
            });
        });
 }

public render() {
    return (<table id='datatable' className='e-table'>
            <thead>
                <tr><th>Order ID</th><th>Customer ID</th><th>Employee ID</th></tr>
            </thead>
            <tbody>{getValue('items', this.state)}</tbody>
            <tfoot>{getValue('aggregates', this.state)}</tfoot>
        </table>)
}

}

import * as React from 'react';
import { IOrders } from './orders';

export class Row extends React.Component<{}, {}>{
    public render() {
        const item: IOrders = this.props as IOrders; 
        return (<tr>
                 <td>{item.OrderID}</td>
                 <td>{item.CustomerID}</td>
                 <td>{item.EmployeeID}</td>
                </tr>)
    }
}

import { Aggregates } from '@syncfusion/ej2-data';
import * as React from 'react';

export class AggregateRow extends React.Component<{}, {}>{
    public render() {
        const item: Aggregates = this.props as Aggregates;
        return (<tr>
                 <td/>
                 <td/>
                 <td>Min: {item.min}</td>
                </tr>)
    }
}

export interface IOrders {
    OrderID: number; 
    EmployeeID: number; 
    CustomerID: string; 
    Order_Details: object[]; 
}

Hierarchical query

You can use the hierarchy method to build nested query. The hierarchical queries are commonly required when you use foreign key binding.

The foreignKey method is used to specify the key field of the foreign table and the second argument of the hierarchy method accepts a selector function which selects the records from the foreign table.

Source

Preview

App.tsx

rowTemplate.tsx

childTemplate.tsx

orders.tsx

import { getValue } from '@syncfusion/ej2-base';
import { DataManager, ODataAdaptor, Query, ReturnOption } from '@syncfusion/ej2-data';
import * as React from 'react';
import { IOrders } from './orders';
import { Row } from './rowTemplate';

const SERVICE_URI: string = 'http://mvc.syncfusion.com/Services/Northwnd.svc/';

export default class App extends React.Component<{}, {}>{
constructor(props: object) {
    super(props);
    this.state = { items: [], aggregates: [] };
    new DataManager({ url: SERVICE_URI, adaptor: new ODataAdaptor })
    .executeQuery(new Query().from('Orders').take(3).hierarchy(
        new Query()
            .foreignKey("OrderID")
            .from("Order_Details")
            .sortBy("Quantity"),
        () => [10248, 10249, 10250] // Selective loading of child elements
        ))
        .then((e: ReturnOption) => {
            const res = (e.result as IOrders[]).map((row: IOrders) => (<Row {...row}/>));
            this.setState({
                items: res
            });
        });
 }

public render() {
    return (<table id='datatable' className='e-table'>
            <thead>
                <tr><th>Order ID</th><th>Customer ID</th><th>Employee ID</th></tr>
            </thead>
            {getValue('items', this.state)}
        </table>)
}

}

import * as React from 'react';
import { ChildRow } from './childTemplate';
import { IOrders } from './orders';

export class Row extends React.Component<{}, {}>{
    public getRows(data: object[]) {
        const dat: object[]=data.map((row: object) => (<ChildRow {...row}/>));
        return dat;
    }
    public render() {
        const item: IOrders = this.props as IOrders; 
        return (<tbody><tr>
            <td>{item.OrderID}</td>
            <td>{item.CustomerID}</td>
            <td>{item.EmployeeID}</td>
           </tr>
           <tr><td colSpan={3}>
           <table id='datatable' className='e-table'>
               <thead><tr><th>ID</th><th>Price</th><th>Quantity</th></tr></thead>
               <tbody>{ this.getRows(item.Order_Details)}</tbody>
           </table>
           </td></tr>
           </tbody>)
    }
}

import * as React from 'react';

interface IProducts { ProductID: number; UnitPrice: number; Quantity: number; }


export class ChildRow extends React.Component<{}, {}>{
    public render() {
        const item: IProducts = this.props as IProducts;     
        return (<tr>
            <td>{item.ProductID}</td>
            <td>{item.UnitPrice}</td>
            <td>{item.Quantity}</td>
           </tr>)
    }
}

export interface IOrders {
    OrderID: number; 
    EmployeeID: number; 
    CustomerID: string; 
    Order_Details: object[]; 
}

Contents

Specifying resource name using
Projection using select
Eager loading navigation properties
Sorting
Filtering
Filter Operators
Build complex filter criteria using
Searching
Grouping
Paging
Aggregation
Hierarchical query

Contents

Specifying resource name using
Projection using select
Eager loading navigation properties
Sorting
Filtering
Filter Operators
Build complex filter criteria using
Searching
Grouping
Paging
Aggregation
Hierarchical query

Please provide additional information

Thank you for your feedback and comments.We will rectify this as soon as possible!

Querying in React DataManager component

Specifying resource name using from

Projection using select

Eager loading navigation properties

Sorting

Filtering

Filter Operators

Build complex filter criteria using Predicate

Searching

Grouping

Paging

Aggregation

Hierarchical query

Specifying resource name using `from`

Build complex filter criteria using `Predicate`