Docker Compose for Multicontainer应用程序未连接到数据库

Question

我正在尝试创建docker-compose文件来为我的ASP.NET Core应用协调多个容器。但是，由于出现错误“建立与SQL Server的连接时发生与网络相关或特定于实例的错误。找不到服务器或无法访问该服务器”，我无法连接到SQL Linux服务器。错误代码为139-数据库连接出现问题。

docker-compose.yml

version: '3.5'

services:
  tag1:
    image: repousername/reponame:tag1
    environment:
     - ASPNETCORE_ENVIRONMENT=Docker
    deploy:
      replicas: 1
      resources: 
        limits:
          cpus: "0.3"
          memory: 500M
      restart_policy:
        condition: on-failure    
    ports:
      - "44444"
    depends_on:
      - db
  tag2:
    image: repousername/reponame:tag2
    environment:
     - ASPNETCORE_ENVIRONMENT=Docker
    deploy:
      replicas: 1
      resources: 
        limits:
          cpus: "0.3"
          memory: 500M
      restart_policy:
        condition: on-failure
    ports:
      - "55555"
    depends_on:
      - db
      - tag1
  db:
    image: "mcr.microsoft.com/mssql/server"
    environment:
        SA_PASSWORD: "<strong_password>"
        ACCEPT_EULA: "Y"

这是我用来连接数据库的连接字符串：

Server=db; Initial Catalog = somecatalog;User Id=SA; Password=<strong_password>; MultipleActiveResultSets=True

请问问题是否与连接字符串或docker-compose.yml文件有关？