Dapper

CREATE TABLE `t_schools` (
`Id`  int(11) NOT NULL AUTO_INCREMENT ,
`Name`  varchar(20)  NOT NULL ,
`Address`  varchar(50)  NOT NULL ,
PRIMARY KEY (`Id`)
)

CREATE TABLE `t_students` (
`Id`  int(11) NOT NULL AUTO_INCREMENT ,
`Name`  varchar(15) NOT NULL ,
`Number`  varchar(15)  NOT NULL ,
`SchoolId`  int(11) NOT NULL ,
`Gender`  enum(‘男‘,‘女‘,‘保密‘) NOT NULL ,
PRIMARY KEY (`Id`)
)

class School
{
    /*
      若属性名和数据库字段不一致则查询不出数据，如果使用EF则可以通过Column特性
      建立属性和数据表字段之间的映射关系，Dapper则不行
    */
    //[Column("Name")]
    public string Title { set; get; }
    public string Address { set; get; }
}

class Student
{
    public string Name { set; get; }
    public string Number { set; get; }
    public int SchoolId { set; get; }
}

const string _connectionString = "Database=Dapper;Data Source=127.0.0.1;User Id=root;Password=root;pooling=false;CharSet=utf8;port=3306;";
using (IDbConnection dbConnection = new MySqlConnection(_connectionString))
{
    dbConnection.Open();
    //通过匿名类型插入单条数据
    dbConnection.Execute("insert into t_schools(Name,Address) values(@Name,@Address)", new { Name = "西南大学", Address = "重庆市北碚区天生路2号" });
    //批量插入数据
    List<School> schools = new List<School>()
    {
      new School() {Address="China·BeiJing",Title="清华大学" },
      new School() {Address="杭州",Title="浙江大学" },
      new School() {Address="不知道，US?",Title="哈弗大学" }
    };
    //在执行参数化的SQL时，SQL中的参数（如@title可以和数据表中的字段不一致，但要和实体类型的属性Title相对应）
    dbConnection.Execute("insert into t_schools(Address,Name) values(@address,@title);", schools);
    //通过匿名类型批量插入数据
    dbConnection.Execute("insert into t_schools(Address,Name) values(@address,@name)", 
    new[] {
      new {Address="杨浦区四平路1239号",Name="同济大学"},
      new {Address="英国",Name="剑桥"},
      new {Address="美国·硅谷",Name="斯坦福大学"}
    });
}

var schools = dbConnection.Query<School>("select * from t_schools where Name=@name", new { Name = "西南大学" });
foreach (var school in schools)
{
    Console.WriteLine(school.Address);
}

//查询结果result是匿名类型
var result = dbConnection.Query("select * from t_schools limit 0,3");
var resultList = result.AsList();
foreach (var l in resultList)
{
    Console.WriteLine(l.Name);
}

var result = dbConnection.Query<Student>("select * from t_students where SchoolId in @schoolId", new { schoolId = new int[] { 2, 3 } });
foreach (var r in result)
{
    var ps = r.GetType().GetProperties();
    foreach (var p in ps)
    {
        Console.Write(p.Name + "=" + p.GetValue(r) + " ");
    }
    Console.WriteLine();
}

var result = dbConnection.Query<School>("select Name,Address from t_schools where Id between @start and @end", new { start = 2, end = 4 });
foreach (var r in result)
{
    var ps = r.GetType().GetProperties();
    foreach (var p in ps)
    {
        Console.Write(p.Name + "=" + p.GetValue(r) + " ");
    }
    Console.WriteLine();
}

var result = dbConnection.Query<Student, School, string>("select s.Name,sc.Address from t_students s,t_schools sc where s.SchoolId=sc.Id and binary sc.Address like ‘%BeiJing%‘",
    (s, sc) =>
    {
        return s.Name + " " + sc.Address;
    }, 
    /*
    还有一点需要特别注意，泛型参数的顺序必须和SQL语句查询数据表的顺序一致，
    即Student对应t_students表的查询结果s.Name，否则Query方法的查询结果
    可能为null（这点也是困扰小编很久......）
    */
    splitOn: "Address"
    );
foreach (var r in result)
{
    Console.WriteLine(r);
}

string sql = "select Address from t_schools;select SchoolId from t_students;select Name from t_students";
using (var multipleReader = dbConnection.QueryMultiple(sql))
{
    //一次执行N条SQL语句则最多只能调用N次Read方法，否则抛异常:the reader has been disposed.
    //Dapper读取查询结果数据的顺序必须要和查询语句中的查询顺序一致，否则可能读取不到数据
    var schoolList = multipleReader.Read<School>();
    foreach (var s in schoolList)
    {
        Console.Write(s.Address + " ");
    }
    Console.WriteLine();
    var studentSchools = multipleReader.Read<Student>();
    foreach (var s in studentSchools)
    {
        Console.Write(s.SchoolId + " ");
    }
    Console.WriteLine();
    var studentNames = multipleReader.Read<Student>();
    foreach (var s in studentNames)
    {
        Console.Write(s.Name + " ");
    }
}

using (IDbTransaction tran = dbConnection.BeginTransaction())
{
    try
    {
        dbConnection.Execute("delete from t_schools where Id=3");
        throw new Exception();
        tran.Commit();
    }
    catch
    {
        tran.Rollback();
    }
}

DROP PROCEDURE IF EXISTS `GetSchoolName`;
CREATE PROCEDURE `GetSchoolName`(in schoolId int,out scname varchar(20))
BEGIN
select `Name` into scname from t_schools where Id=schoolId;
select scname; 
END;

//在程序中调用存储过程时，存储过程名要小写，传递的参数名要和存储过程中的参数名一致（不区分大小写）
//连接字符串中的数据库名也要小写，否则抛异常：在数据库***中找不到存储过程×××
var parameters = new DynamicParameters();
parameters.Add("@scname", dbType: DbType.String, direction: ParameterDirection.Output);
parameters.Add("schoolid", 6, direction: ParameterDirection.Input);
var result = dbConnection.Query("getschoolname", parameters, commandType: CommandType.StoredProcedure);