Dapper学习笔记

连接数据库

var connection = new SqlConnection("Data Source=1.1.1.1;Initial Catalog=Test;User ID=sa;Password=123;MultipleActiveResultSets=True");

多表关联

 1 　　　　　　 var sql = @"select top 10 mj.MajorID,mj.MajorName,ms.MinScore,sc.SchoolID,sc.SchoolName,sc.Address from Major mj 
 2                         join MajorScore ms on mj.MajorID = ms.MajorID 
 3                         join School sc on ms.SchoolID = sc.SchoolID
 4                         where sc.SchoolID = @SchoolID and  ms.Year = @Year";
 5 
 6             var sss = connection.Query<Major, MajorScore, School, ResultInfo>(sql, (mj, ms, sc) =>
 7              {
 8                  var result = new ResultInfo
 9                  {
10                      MajorID = mj.MajorID,
11                      MajorName = mj.MajorName,
12                      Score = ms.MinScore,
13                      SchoolID = sc.SchoolID,
14                      SchoolName = sc.SchoolName,
15                      Address = sc.Address
16                  };
17                  return result;
18              }, splitOn: "MinScore,SchoolID", param: new { SchoolID = "10226", Year = "2016" });

splitOn：用于标识关联表的首个字段名，多个关联表时用“，”分割。

查询多个表

1 　　　　　　　sql = @"select * from CityInfo;select * from Major;";
2 
3             var multiReader = connection.QueryMultiple(sql);
4 
5             var cityList = multiReader.Read<CityInfo>();
6 
7             var majorList = multiReader.Read<Major>();

 

In操作

1             sql = @"select * from CityInfo where ProvinceID in @ProvinceID ;";
2 
3             var info = connection.Query<CityInfo>(sql, new { ProvinceID = new List<string> { "110000", "120000" } });

Insert操作

1             var sql = @"insert into Test values (@Name,@Pwd);";
2             var insert = connection.Execute(sql, new { Name = "test", Pwd = "123" });

批量插入

 1             sql = @"insert into Test values (@Name,@Pwd);";
 2 
 3             var list = new List<Test>
 4             {
 5                 new Test{Name="1",Pwd="1"},
 6                 new Test{Name="2",Pwd="2"},
 7                 new Test{Name="3",Pwd="3"},
 8             };
 9 
10             var insert = connection.Execute(sql, list);

Update操作

1             sql = @"update Test set Name = @Name where ID = @ID ;";
2 
3             var update = connection.Execute(sql, new { Name = "hello", ID = 2 });