OData V4 Service modules - TYPEORM Connector
Service OData v4 requests from a TYPEORM.
Synopsis
The OData V4 TYPEORM Connector provides functionality to convert the various types of OData segments into SQL query statements, that you can execute over a TYPEORM.
Potential usage scenarios
- Create high speed, standard compliant data sharing APIs
Usage as server - TypeScript
example request: GET /api/users?$filter=id eq 42&$select=id,name
NestJS middleware
- middleware
import { Inject, Injectable, NestMiddleware } from '@nestjs/common';
import { Request, Response } from 'express';
import { odataQuery } from 'odata-v4-typeorm';
import { Repository } from 'typeorm';
import { UserEntity } from '../entities/user.entity';
@Injectable()
export class OdataUsersMiddleware implements NestMiddleware {
constructor(
@Inject('USERS_REPOSITORY') private readonly usersRepository: Repository<UserEntity>
) {}
use(req: Request, res: Response, next: Function) {
odataQuery(this.usersRepository)(req, res, next);
}
}users repository provider
import { Connection } from 'typeorm';
import { UserEntity } from '../user.entity';
export const userProviders = [
{
provide: 'USERS_REPOSITORY',
useFactory: (connection: Connection) => connection.getRepository(UserEntity),
inject: ['DATABASE_CONNECTION'],
}
];database provider
import { createConnection } from 'typeorm';
import { UserEntity } from '../entities/user.entity';
export const databaseProviders = [
{
provide: 'DATABASE_CONNECTION',
useFactory: async () => await createConnection({
type: 'postgres',
host: 'localhost',
port: 3306,
username: 'postgres',
password: 'root',
database: 'test',
synchronize: true,
entities: [UserEntity]
}),
},
];app module
import { MiddlewareConsumer, Module, NestModule } from '@nestjs/common';
import { databaseProviders } from './db/database.providers';
import { userProviders } from './providers/user.providers';
import { OdataUsersMiddleware } from './middlewares/odataUsers.middleware';
@Module({
providers: [
...databaseProviders,
...userProviders,
],
})
export class AppModule implements NestModule {
configure(consumer: MiddlewareConsumer) {
consumer
.apply(OdataUsersMiddleware)
.forRoutes('api/v1/odata/users');
}
}odataQuery
import express from 'express';
import { odataQuery } from 'odata-v4-typeorm';
import { getRepository } from 'typeorm';
import { User } from '../entities/user';
const app = express();
const usersRepository = getRepository(User);
app.get('/api/users', odataQuery(usersRepository));
const port = 3001;
app.listen(port, () => console.log(`Example app listening on port ${port}!`));executeQuery by repository
import express from 'express';
import { executeQuery } from 'odata-v4-typeorm';
import { getRepository } from 'typeorm';
import { User } from '../entities/user';
const app = express();
app.get('/api/users', async (req, res) => {
try {
const usersRepository = getRepository(User);
const data = await executeQuery(usersRepository, req.query);
return res.status(200).json(data);
} catch (e) {
return res.status(500).json({message: 'Internal server error.'});
}
});
const port = 3001;
app.listen(port, () => console.log(`Example app listening on port ${port}!`));executeQuery by queryBuilder
import express from 'express';
import { executeQuery } from 'odata-v4-typeorm';
import { getRepository } from 'typeorm';
import { User } from '../entities/user';
const app = express();
app.get('/api/users', async (req, res) => {
try {
const queryBuilder = getRepository(User)
.createQueryBuilder("user")
.where("user.roleName = :roleName", { roleName: 'admin' });
const data = await executeQuery(queryBuilder, req.query);
return res.status(200).json(data);
} catch (e) {
return res.status(500).json({message: 'Internal server error.'});
}
});
const port = 3001;
app.listen(port, () => console.log(`Example app listening on port ${port}!`));createFilter
import { createFilter } from 'odata-v4-typeorm'
//example request: GET /api/Users?$filter=Id eq 42
app.get("/api/Users", (req: Request, res: Response) => {
const filter = createFilter(req.query.$filter);
// connection instance from pg module
connection.query(`SELECT * FROM Users WHERE ${filter.where}`, filter.parameters, function(err, result){
res.json({
'@odata.context': req.protocol + '://' + req.get('host') + '/api/$metadata#Users',
value: result.rows
});
});
});Advanced TypeScript example available here.
Usage ES5
var createFilter = require('odata-v4-typeorm').createFilter;
app.get("/api/Users", function(req, res) {
var filter = createFilter(req.query.$filter);
// connection instance from pg module
connection.query(filter.from("Users"), filter.parameters, function(err, result){
res.json({
'@odata.context': req.protocol + '://' + req.get('host') + '/api/$metadata#Users',
value: result.rows
});
});
})Supported OData segments
- $filter
- $select
- $skip
- $top
- $orderby
- $expand
- $count
If you have any questions, please don’t hesitate to contact me.
- skype: andryuha49.
- https://www.linkedin.com/in/andriy-zherdiy/
