Kueri OData yang diketik dalam TypeScript

Secara tradisional, pertanyaan OData pada data dinyatakan sebagai string sederhana tanpa pengecekan tipe saat kompilasi atau tanpa dukungan IntelliSense, di samping itu, pengembang harus mempelajari sintaks dari bahasa query. Artikel ini menjelaskan pustaka TsToOdata, yang mengubah kueri menjadi konstruksi bahasa yang nyaman dan diterapkan dengan cara yang mirip dengan kelas dan metode. Anda membuat kueri yang diketik menggunakan kata kunci TypeScript dan operator yang dikenal.

TsToOdata adalah perpustakaan untuk TypeScript. Ini mirip dengan LINQ untuk C #, tetapi, tidak seperti yang terakhir, itu hanya ditujukan untuk permintaan OData. Untuk pengembang yang membuat kueri, bagian paling jelas dari TsToOdata adalah ekspresi kueri. Ekspresi kueri menggunakan sintaksis deklaratif, sehingga pengembang menulis apa yang perlu dilakukan, tanpa menentukan cara melakukannya. Dengan menggunakan sintaks kueri, Anda bisa memfilter, mengatur, dan mengelompokkan data dari sumber data, menggunakan jumlah minimum kode program.

Instal TsToOdata

npm install ts2odata

Membuat model data

Pertama-tama, kita perlu mendapatkan pemetaan skema OData ke kelas-kelas TypeScript.
Langkah pertama adalah pertama mendapatkan skema dari EDMX Json. Anda dapat menggunakan pustaka OdataToEntity untuk ini .

IEdmModel edmModel;
using (var reader = XmlReader.Create("edmx_schema.xml"))
    edmModel = CsdlReader.Parse(reader);

var generator = new OeJsonSchemaGenerator(edmModel);
using (var utf8Json = new MemoryStream())
{
    generator.Generate(utf8Json);
    utf8Json.Position = 0;
    File.WriteAllBytes("json_schema.json", utf8Json.ToArray());
}

Json TypeScript. quicktype.
.

import { EntitySet, OdataContext } from 'ts2odata';
import * as oe from './order';

export class OrderContext extends OdataContext<OrderContext> {
    Categories = EntitySet.default<oe.Category>();
    Customers = EntitySet.default<oe.Customer>();
    OrderItems = EntitySet.default<oe.OrderItem>();
    OrderItemsView = EntitySet.default<oe.OrderItemsView>();
    Orders = EntitySet.default<oe.Order>();
}

let context: OrderContext = OdataContext.create(OrderContext, 'http://localhost:5000/api');

context.Orders;
//http://localhost:5000/api/Orders

context.Orders.select(o => { return { p: o.Name } });
//http://localhost:5000/api/Orders?$select=Name

context.Orders.orderby(i => i.Id);
//http://localhost:5000/api/Orders?$orderby=Id

context.Orders.orderbyDescending(i => i.Id);
//http://localhost:5000/api/Orders?$orderby=Id desc

context.Orders.filter(o => o.Date.getFullYear() == 2016);
//http://localhost:5000/api/Orders?$filter=year(Date) eq 2016

context.Orders.expand(o => o.Items);
//http://localhost:5000/api/Orders?$expand=Items

context.Customers.expand(c => c.Orders).thenExpand(o => o.Items);
//http://localhost:5000/api/Customers?$expand=Orders($expand=Items)

context.Orders.orderby(i => i.Id).skip(2);
//http://localhost:5000/api/Orders?$orderby=Id&$skip=2

context.Orders.orderby(i => i.Id).top(3);
//http://localhost:5000/api/Orders?$orderby=Id&$top=3

context.OrderItems.groupby(i => { return { Product: i.Product } });
//localhost:5000/api/OrderItems?$apply=groupby((Product))

context.OrderItems.groupby(i => { return { OrderId: i.OrderId, Status: i.Order.Status } })
    .select(g => {
        return {
            orderId: g.key.OrderId,
            avg: g.average(i => i.Price),
            dcnt: g.countdistinct(i => i.Product),
            max: g.max(i => i.Price),
            max_status: g.max(_ => g.key.Status),
            min: g.min(i => i.Price),
            sum: g.sum(i => i.Price),
            cnt: g.count()
        }});
//http://localhost:5000/api/OrderItems?$apply=groupby((OrderId,Order/Status),aggregate(Price with average as avg,Product with countdistinct as dcnt,Price with max as max,Order/Status with max as max_status,Price with min as min,Price with sum as sum,$count as cnt))

context.Customers.key({ Country: 'RU', Id: 1 });
//http://localhost:5000/api/Customers(Country='RU',Id=1)

context.OrderItems.key(1, i => i.Order.Customer);
//http://localhost:5000/api/OrderItems(1)/Order/Customer

context.OrderItems
    .select(i => {
        return {
            product: i.Product,
            Total: i.Count * i.Price,
            SumId: i.Id + i.OrderId
        }
    });
//http://localhost:5000/api/OrderItems?$select=Product&$compute=Count mul Price as Total,Id add OrderId as SumId

context.Orders.filter(o => o.Items.every(i => i.Price >= 2.1));
//http://localhost:5000/api/Orders?$filter=Items/all(d:d/Price ge 2.1)

context.Orders.filter(o => o.Items.some(i => i.Count > 2));
//http://localhost:5000/api/Orders?$filter=Items/any(d:d/Count gt 2)

IN

let items = [1.1, 1.2, 1.3];
context.OrderItems.filter(i => items.includes(i.Price), { items: items });
//http://localhost:5000/api/OrderItems?$filter=Price in (1.1,1.2,1.3)

context.Orders.count();
//http://localhost:5000/api/Orders/$count

asEntitySet

context.Orders(o => o.AltCustomer).thenSelect(o => {{
    p1: o.Address,
    : o.Country,
    : o.Id,
    : o.Name,
    : o.Sex
}}).asEntitySet().orderby(o => o.Id)
//http://localhost:5000/api/Orders?$expand=AltCustomer($select=Address,Country,Id,Name,Sex)&$orderby=Id

GitHub.

, select, expand, groupby — — , , then: thenFilter, thenExpand, thenOrderby, thenOrderbyDescending, thenSkip, thenTop. select thenSelect , , , asEntitySet.

— filter/thenFilter, — select/thenSelect, — groupby , .

let count: number | null = null;
context.OrderItems.filter(i => i.Count == count, { count: count }); //http://localhost:5000/api/OrderItems?$filter=Count eq null

let s = {
    altCustomerId: 3,
    customerId: 4,
    dateYear: 2016,
    dateMonth: 11,
    dateDay: 20,
    date: null,
    name: 'unknown',
    status: "OdataToEntity.Test.Model.OrderStatus'Unknown'",
    count1: 0,
    count2: null,
    price1: 0,
    price2: null,
    product1: 'unknown',
    product2: 'null',
    orderId: -1,
    id: 1
};
context.Orders.filter(o => o.AltCustomerId == s.altCustomerId &&
    o.CustomerId == s.customerId &&
    (o.Date.getFullYear() == s.dateYear &&
        o.Date.getMonth() > s.dateMonth &&
        o.Date.getDay() < s.dateDay ||
        o.Date == s.date) &&
    o.Name.includes(s.name) &&
    o.Status == s.status, s)
    .expand(o => o.Items)
        .thenFilter(i => (i.Count == s.count1 ||
                i.Count == s.count2) &&
            (i.Price == s.price1 ||
                i.Price == s.price2) &&
            (i.Product.includes(s.product1) ||
                i.Product.includes(s.product2)) &&
            i.OrderId > s.orderId &&
            i.Id != s.id, s);
/*http://localhost:5000/api/Orders?$filter=AltCustomerId eq 3 and
    CustomerId eq 4 and
    (year(Date) eq 2016 and
        month(Date) gt 11 and
        day(Date) lt 20 or
        Date eq null) and
    contains(Name,'unknown') and
    Status eq OdataToEntity.Test.Model.OrderStatus'Unknown'&
    $expand=Items(
        $filter=(Count eq 0 or
            Count eq null) and
        (Price eq 0 or
            Price eq null) and
        (contains(Product,'unknown') or
            contains(Product,'null')) and
        OrderId gt -1 and
        Id ne 1)*/

OdataFunctions.stringLength

context.Customers.filter(c => OdataFunctions.stringLength(c.Name) == 5); //http://localhost:5000/api/Customers?$filter=length(Name) eq 5

OdataFunctions.arrayLength

context.Orders.filter(o => OdataFunctions.arrayLength(o.Items) > 2); //http://localhost:5000/api/Customers?$filter=Items/$count gt 2

select, filter getQueryUrl toArrayAsync.
getQueryUrl URL . TypeScript:

let url: URL = context.Customers
    .expand(c => c.AltOrders).thenExpand(o => o.Items).thenOrderby(i => i.Price)
    .expand(c => c.AltOrders).thenExpand(o => o.ShippingAddresses).thenOrderby(s => s.Id)
    .expand(c => c.Orders).thenExpand(o => o.Items).thenOrderby(i => i.Price)
    .expand(c => c.Orders).thenExpand(o => o.ShippingAddresses).thenOrderby(s => s.Id)
    .orderby(c => c.Country).orderby(c => c.Id).getQueryUrl();

OData :

http://localhost:5000/api/Customers?$expand=
AltOrders($expand=Items($orderby=Price),ShippingAddresses($orderby=Id)),
Orders($expand=Items($orderby=Price),ShippingAddresses($orderby=Id))
&$orderby=Country,Id

toArrayAsync Json. TypeScript:

context.Customers
    .expand(c => c.Orders).thenSelect(o => { return { Date: o.Date } }).orderby(o => o.Date)
    .asEntitySet().select(c => { return { Name: c.Name } }).orderby(c => c.Name).toArrayAsync();

Json:

[{
        "Name": "Ivan",
        "Orders": [{
                "Date": "2016-07-04T19:10:10.8237573+03:00"
            }, {
                "Date": "2020-02-20T20:20:20.000002+03:00"
            }
        ]
    }, {
        "Name": "Natasha",
        "Orders": [{
                "Date": "2016-07-04T19:10:11+03:00"
            }
        ]
    }, {
        "Name": "Sasha",
        "Orders": []
    }, {
        "Name": "Unknown",
        "Orders": [{
                "Date": null
            }
        ]
    }
]

, , toArrayAsync OdataParser:

import { OdataParser } from 'ts2odata';
import schema from './schema.json';

let odataParser = new OdataParser(schema);
context.Orders.toArrayAsync(odataParser);

(enum)

OData (Namespace), :

let context: OrderContext = OdataContext.create(OrderContext, 'http://localhost:5000/api', 'OdataToEntity.Test.Model');

Dalam beberapa kasus, terjemahan enumerasi mungkin memerlukan pembuatan objek OdataParser .

import { OdataParser } from 'ts2odata';
import schema from './schema.json';

let odataParser = new OdataParser(schema);
let context: OrderContext = OdataContext.create(OrderContext, 'http://localhost:5000/api', 'OdataToEntity.Test.Model', odataParser);

Sumber

Kode sumber ada di GitHub .
Di folder sumber - kode Node paket, di folder tes - tes.

Saya harap proyek TsToOdata saya akan berguna bagi Anda dan menyelamatkan Anda dari rutinitas menulis kode monoton.