.net core下配置訪問數據庫操作

配置讀取

.net core下讀取配置還是有點麻煩的,本身沒有System.Configuration.dll,所以在進行配置前需要自行引用Microsoft.Extensions.Configuration,截圖如下:

這樣的話我們就可以配置讀取的相關編碼了,比如我們數據庫的鏈接字符串,在appsettings.json添加對應的數據庫配置:

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"ConnectionStrings": {

"TestDb": "server=localhost;port=3306;database=mytest;user=test;password=123456;charset=utf8;"

}

"ConnectionStrings": { "TestDb": "server=localhost;port=3306;database=mytest;user=test;password=123456;charset=utf8;" }

讀取配置相關代碼如下:

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public class AppSetting

{

 private static readonly object objLock = new object();

 private static AppSetting instance = null;

 

 private IConfigurationRoot Config { get; }

 

 private AppSetting()

 {

 var builder = new ConfigurationBuilder()

  .SetBasePath(Directory.GetCurrentDirectory())

  .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true);

 Config = builder.Build();

 }

 

 public static AppSetting GetInstance()

 {

 if (instance == null)

 {

  lock (objLock)

  {

  if (instance == null)

  {

   instance = new AppSetting();

  }

  }

 }

 

 return instance;

 }

 

 public static string GetConfig(string name)

 {

 return GetInstance().Config.GetSection(name).Value;

 }

}

public class AppSetting { private static readonly object objLock = new object(); private static AppSetting instance = null; private IConfigurationRoot Config { get; } private AppSetting() { var builder = new ConfigurationBuilder() .SetBasePath(Directory.GetCurrentDirectory()) .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true); Config = builder.Build(); } public static AppSetting GetInstance() { if (instance == null) { lock (objLock) { if (instance == null) { instance = new AppSetting(); } } } return instance; } public static string GetConfig(string name) { return GetInstance().Config.GetSection(name).Value; } }

這樣就可以直接讀取對應的配置信息啦:

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string CONNECTION_STRING = AppSetting.GetConfig("ConnectionStrings:TestDb");

string CONNECTION_STRING = AppSetting.GetConfig("ConnectionStrings:TestDb");

數據庫操作

數據庫相關操作還是建議使用Dapper以及Dapper.Contrib,比較輕量,也比較方便。

Dapper相信大家還是比較熟悉的,這裏簡單說下Dapper.Contrib,基於Dapper的擴展方法,封裝瞭如下方法:

  • T Get<T>(id);
  • IEnumerable<T> GetAll<T>();
  • int Insert<T>(T obj);
  • int Insert<T>(Enumerable<T> list);
  • bool Update<T>(T obj);
  • bool Update<T>(Enumerable<T> list);
  • bool Delete<T>(T obj);
  • bool Delete<T>(Enumerable<T> list);
  • bool DeleteAll<T>();

這樣對應你應用的簡單的CRUD方法可以很輕鬆的搞定的。比如下面幾個例子:

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//根據主鍵Id查詢

using (var conn = DatabaseManager.GetConnection(DatabaseManager.DBName))

{

 await conn.OpenAsync();

 return await conn.GetAsync<UserModel>(id);

}

//根據主鍵Id查詢 using (var conn = DatabaseManager.GetConnection(DatabaseManager.DBName)) { await conn.OpenAsync(); return await conn.GetAsync<UserModel>(id); }

新增數據:

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//新增

using (var conn = DatabaseManager.GetConnection(DatabaseManager.DBName))

{

 await conn.OpenAsync();

 await conn.InsertAsync(entity);

}

//新增 using (var conn = DatabaseManager.GetConnection(DatabaseManager.DBName)) { await conn.OpenAsync(); await conn.InsertAsync(entity); }

修改數據:

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//修改

using (var conn = DatabaseManager.GetConnection(DatabaseManager.DBName))

{

 await conn.OpenAsync();

 await conn.UpdateAsync(entity);

}

//修改 using (var conn = DatabaseManager.GetConnection(DatabaseManager.DBName)) { await conn.OpenAsync(); await conn.UpdateAsync(entity); }

需要注意的是,需要給對應的實體加上特性:

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[Table("User")]

public class UserModel

{

 [Key]

 public int Id { get; set; }

 public string UserName { get; set; }

 public string Remark { get; set; }

}

[Table("User")] public class UserModel { [Key] public int Id { get; set; } public string UserName { get; set; } public string Remark { get; set; } }

  • [Table("Tablename")] 標識對應的表名
  • [Key] 對應的主鍵
  • [ExplicitKey] 如果主鍵不是自增長的,用此標識
  • [Write(true/false)] 該字段是否可被寫入
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