nest 记录（三）

统一返回格式

需要用到管道

import { CallHandler, ExecutionContext, Injectable, NestInterceptor } from '@nestjs/common';import { Observable } from 'rxjs';import { map } from 'rxjs/operators';@Injectable()
export class TransformInterceptor implements NestInterceptor {
    intercept(context: ExecutionContext, next: CallHandler): Observable<any> {
        return next.handle().pipe(
            map((data) => ({
                code: 200,                data,                message: 'success',            })),        );    }
}
// main.tsimport { TransformInterceptor } from './interceptor/transform.interceptor';app.useGlobalInterceptors(new TransformInterceptor());

统一错误捕捉

import { ArgumentsHost, Catch, ExceptionFilter, HttpException } from '@nestjs/common';import { Response } from 'express';@Catch(HttpException) // 这里只捕捉了httpExceptionexport class HttpExceptionFilter implements ExceptionFilter {
    catch(exception: any, host: ArgumentsHost) {
        const context = host.switchToHttp();        const response = context.getResponse<Response>();        const status = exception.getStatus();        const message = exception.message;        response.status(status).json({ // 和上面的返回格式一样            code: status,            data: null,            message: message,        });    }
}
// main.tsimport { HttpExceptionFilter } from './common/filter/httpException.filter';app.useGlobalFilters(new HttpExceptionFilter());

知道这些就可以写一个demo了。像mysql连接这些不需要记录。
连接后定义sql就行