Asp.Net Core 3.0 開發之旅之.net core 3.0 鏈接數據庫

數據庫鏈接字符串放入配置文件中

打開appsettings.json

添加ConnectionStrings

例子以下:

{
  "Logging": {
    "IncludeScopes": false,
    "LogLevel": {
      "Default": "Warning"
    }
  },
  "ConnectionStrings": {
    "BaseDb": "Server=********;Initial Catalog=******;User ID=**;Password=*********;MultipleActiveResultSets=true"
  }
}

 

配置上下文

using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.EntityFrameworkCore;
using Dw.Models.FindLove;
using Dw.Util;

namespace Dw.Models
{
    /// <summary>
    /// 數據訪問(SqlServer) 上下文
    /// </summary>
    public class MsSqlDbContext : DbContext
    {
        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            optionsBuilder.UseSqlServer(Config.GetValue("ConnectionStrings:BaseDb"));
            base.OnConfiguring(optionsBuilder);
        }

        public DbSet<FL_User> FL_User { get; set; }
    }
}

 注意引用安裝包：

Microsoft.EntityFrameworkCore 和 Microsoft.EntityFrameworkCore.SqlServer

讀取json配置文件輔助類Config

using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using Microsoft.Extensions.Configuration;

namespace Dw.Util
{
    /// <summary>
    /// 配置文件
    /// </summary>
    public class Config
    {
        #region 根據Key取Value值
        /// <summary>
        /// 根據Key取Value值
        /// </summary>
        /// <param name="key"></param>
        public static string GetValue(string key)
        {
            var configJson = GetJsonConfig();
            return configJson[key];
        }
        #endregion

        #region json配置文件讀取
        /// <summary>
        /// json配置文件讀取
        /// </summary>
        /// <param name="configFileName"></param>
        /// <param name="basePath"></param>
        /// <returns></returns>
        public static IConfigurationRoot GetJsonConfig(string configFileName = "appsettings.json", string basePath = "")
        {
            basePath = string.IsNullOrWhiteSpace(basePath) ? Directory.GetCurrentDirectory() : basePath;
            var builder = new ConfigurationBuilder().SetBasePath(basePath).AddJsonFile(configFileName);
            return builder.Build();
        }
        #endregion
    }
}