轻量级ORM框架—Dapper
Dapper是.NET下一个Micro的ORM，它和Entity Framework或NHibnate不同，属于轻量级的，并且是半自动的。也就是说实体类都要自己写。它没有复杂的配置文件，一个单文件就可以了。Dapper相当于Java里的Mybatis。
个人觉得他非常好用，现在已经取代了原来的SqlHelper。优点：
- 使用Dapper可以自动进行对象映射！
- 轻量级，单文件。
代码就一个SqlMapper.cs文件，编译后就40K的一个很小的Dll. - 支持多数据库。
Dapper支持Mysql,SqlLite,Mssql2000,Mssql2005,Oracle等一系列的数据库，当然如果你知道原理也可以让它支持Mongo db，支持多数据库的本质是因为Dapper是对IDBConnection接口进行了方法扩展，
比如你看到的SqlMapper.cs，一旦你这样做了，
我们也知道，SqlConnection,MysqlConnection,OracleConnection都是继承于DBConnection，
而DBConnection又是实现了IDBConnection的接口，对吧。。。 - Dapper原理通过Emit反射IDataReader的序列队列，来快速的得到和产生对象。性能实在高高高。
- Dapper语法简单，如果你喜欢写原始的sql，你一定喜欢Dapper。同时团队人员也很容易上手；
- Dapper 速度快，速度接近ADO.NET访问数据库的效率；
基本的增删改查操作
Insert
Update
public int UpdateScanOmr(TB_SCAN_OMR1 model)
{
string sqlstr = "UPDATE TB_SCAN_OMR1 " +
"SET FINALOMR = :FINALOMR," +
" SCORE = :SCORE, " +
" SCOREDETAIL = :SCOREDETAIL" +
" WHERE EXAMID = :EXAMID" +
" AND PAPERID = :PAPERID";
using (ExamConn)
{
return ExamConn.Execute(sqlstr, model);
}
}
Delete
Query
- 无参数查询，返回列表
public List GetAllExam()
{
var sqlstr = "SELECT * FROM TB_EXAM ORDER BY SDATE DESC";
using (EmsConn)
{
return EmsConn.Query(sqlstr).ToList();
}
}
var entityList1 = new OmrRepository().GetAllExam();
foreach (var item in entityList1)
{
Console.WriteLine(new Guid((byte[])item.EXAMGUID).ToString() + " " + item.EXAMNUM + " " + item.EXAMNAME);
}
- 带参数查询
public List GetScanPageListByPaperId(string paperId)
{
var sqlstr = "SELECT * FROM TB_SCAN_PAGE T WHERE T.PAPERID = :paperId";
using (ExamConn)
{
return ExamConn.Query(sqlstr, new { paperId }).ToList();
}
}
- 单条信息
public TB_AREA GetAreaDeail(string examId,string areaId)
{
var sqlstr = @"SELECT * FROM TB_AREA WHERE EXAMID = :examId AND AREAID = :areaId";
using (ExamConn)
{
return ExamConn.Query(sqlstr, new { examId, areaId }).Single();
}
}
事务操作
Dapper Extensions
Dapper-Extensions也是一个开源库，他在Dapper的基础上封装了基本的CRUD操作，使得一些简单的数据库操作可以不用自己写sql语句。使用起来更方面。
Dapper Extensions是github上的一个开源库是对StackOVerflow开发的Dapper ORM的一个扩展。它增加了基础的CRUD操作（(Get, Insert, Update, Delete)），对更高级的查询场景，该类库还提供了一套谓词系统。它的目标是保持POCOs的纯净，不需要额外的attributes和类的继承。
Features
- 零配置
- 自动映射POCOs的CRUD操作
- GetList, Count等方法可以用于更高级的场景。
- GetPage for returning paged result sets.支持分页
- 自动支持Guid和Integer类型的主键，（也可以手动指定其他键类型）
- 通过使用ClassMapper可以使保证POCOs纯净。 (Attribute Free!)
- 可以通过使用ClassMapper来自定义entity-table映射
- 支持联合主键
- POCO类名默认与数据表名相匹配，也可以自定义
- 易于使用的 Predicate System适用于高级场合
- 在生成SQL语句时正确转义表名和类名 (Ex: SELECT FirstName FROM Users WHERE Users.UserId = @ UserId_0）
- 覆盖单元测试（覆盖了150+个单元测试）
Tdf.Dapper
more extensions for dapper
The full list of extension methods in Tdf.Dapper right now are:
Task ExecuteScalarAsync(string sql, object param = null, IDbTransaction transaction = null, int? commandTimeout = default(int?), CommandType? commandType = default(CommandType?));
Task> QueryAsync(string sql, object param = null, IDbTransaction transaction = null, int? commandTimeout = default(int?), CommandType? commandType = default(CommandType?));
Task> QueryAsyncDynamic(string sql, object param = null, IDbTransaction transaction = null, int? commandTimeout = default(int?), CommandType? commandType = default(CommandType?));
Task ExecuteAsync(string sql, object param = null, IDbTransaction transaction = null, int? commandTimeout = default(int?), CommandType? commandType = default(CommandType?));
Task GetAsync(int id, IDbTransaction transaction = null, int? commandTimeout = null);
Task GetAsync(long id, IDbTransaction transaction = null, int? commandTimeout = null);
Task GetAsync(System.Guid id, IDbTransaction transaction = null, int? commandTimeout = null);
Task GetAsync(string id, IDbTransaction transaction = null, int? commandTimeout = null);
Task InsertAsync(T model, IDbTransaction transaction = null, int? commandTimeout = null);
Task DeleteAsync(T model, IDbTransaction transaction = null, int? commandTimeout = null);
Task UpdateAsync(T model, IDbTransaction transaction = null, int? commandTimeout = null);
Task GetPageAsync(string sql, object p = null, string sqlTotal = "", object p2 = null);
Task GetPageAsync(PageInput model, string tableName, string sqlWhere, dynamic pms1, dynamic pms2);
Features
For these extensions to work, the entity in question MUST have a key-property, a property named "id" or decorated with a [Key] attribute.
[Table("TB_COURSE")]
public class Course
{
[Key]
public int COURSEID { get; set; }
public string COURSECODE { get; set; }
public string COURSENAME { get; set; }
public string DESCRIPTION { get; set; }
public int DIS_ORDER { get; set; }
}
[Table("Act_Action")]
public class Action
{
[Key]
public Guid ActionId { get; set; }
public string ActionName { get; set; }
public int ActionValue { get; set; }
}
Get methods
or a list of all entities in the table.
var entity = await new DapperRepositoryBase().GetAllAsync();
foreach (var item in entity)
{
Console.WriteLine(item.ActionId + " " + item.ActionName + " " + item.ActionValue);
}
var course = await new DapperRepositoryBase().GetAllAsync();
foreach (var item in course)
{
Console.WriteLine(item.COURSEID + " " + item.COURSENAME);
}
Get one specific entity based on id
var actionId = new Guid("3F4DB83E-4D24-4875-8AC6-D4DA2F5F21B3");
var entity = await new DapperRepositoryBase().GetAsync(actionId);
if (entity != null)
{
Console.WriteLine(entity.ActionId + " " + entity.ActionName + " " + entity.ActionValue);
}
var list = await new DapperRepositoryBase().QueryAsync("select top 1 ActionId,ActionName,ActionValue from Act_Action where ActionId=@ActionId and ActionValue=8", new { ActionId = "66307CAB-3394-4675-8FB3-5A8C90F6CD70" });
if (list != null && list.Count() > 0)
{
Console.WriteLine("Ok");
}
// 强类型查询
var courseId = 4;
var course = await new DapperRepositoryBase().QueryAsync("SELECT * FROM TB_COURSE T WHERE COURSEID = :courseId", new { courseId });
foreach (var item in course)
{
Console.WriteLine(item.COURSEID + " " + item.COURSENAME);
}
Console.Read();
```
**分页查询**
分页采用的Sql
```
SELECT *
FROM ( SELECT row_number() OVER ( ORDER BY ActionValue ) Id ,
*
FROM ( SELECT *
FROM Act_Action
) TempA
) AS TempInfo
WHERE Id <= 1 * 2
AND Id > ( 1 - 1 ) * 2
```
```
var model = new PageInput();
model.OrderStr = "ActionValue";
model.PageIndex = 0; // 当前索引，第一页
model.PageSize = 2; // 每页多少条
model.Offset = model.PageIndex * model.PageSize;
var sqlWhere = new System.Text.StringBuilder();
dynamic pms1 = new System.Dynamic.ExpandoObject();
dynamic pms2 = new System.Dynamic.ExpandoObject();
//sqlWhere.Append(" where ActionValue=@ActionValue");
//pms1.ActionValue = 8;
//sqlWhere.Append(" and ActionName like @ActionName");
//pms1.ActionName = string.Format("%{0}%", "查询");
pms2 = pms1;
pms2.OrderStr = model.OrderStr;
var pageOutput = await new DapperRepositoryBase().GetPageAsync(model, "Act_Action", sqlWhere.ToString(), pms1, pms2) as PageOutput;
var list = new List();
foreach (dynamic item in pageOutput.Records)
{
list.Add(new Action
{
ActionId = item.ActionId,
ActionName = item.ActionName,
ActionValue = item.ActionValue
});
}
foreach (var item in list)
{
Console.WriteLine(item.ActionId + " " + item.ActionName + " " + item.ActionValue);
}
```
## Insert methods
```
var action = new Action();
action.ActionName = "删除";
action.ActionValue = 4;
var result = await new DapperRepositoryBase().InsertAsync(action);
if (result == 0)
{
Console.WriteLine("添加成功");
}
```
```
var list = new List();
list.Add(new Action()
{
ActionName = "编辑",
ActionValue = 2
});
var count = await new DapperRepositoryBase().ExecuteAsync("insert into Act_Action(ActionName,ActionValue) values(@ActionName,@ActionValue)", list);
if (count > 0)
{
Console.WriteLine("成功添加了 {0} 个记录 ", count);
}
else
{
Console.WriteLine("操作失败，请重试");
}
```
## Delete methods
**a list of entities**
```
var action = new Action();
action.ActionId = new Guid("7ACDAFAF-E3B0-4458-A4F3-6D378F063C52");
var result = await new DapperRepositoryBase().DeleteAsync(action);
if (result)
{
Console.WriteLine("删除成功");
}
else
{
Console.WriteLine("删除失败");
}
```
## Update methods
update a list of entities.
```
// F77F6678-3A7C-4848-94AF-B737A2BC7DD7 编辑 2
// F77F6678-3A7C-4848-94AF-B737A2BC7DD7 导入 64
var action = new Action();
action.ActionId = new Guid("F77F6678-3A7C-4848-94AF-B737A2BC7DD7");
action.ActionName = "导入";
action.ActionValue = 64;
var result = await new DapperRepositoryBase().UpdateAsync(action);
if (result != null)
{
Console.WriteLine("更新成功");
}
else
{
Console.WriteLine("更新失败");
}
```
```
int i = await new DapperRepositoryBase().ExecuteAsync("update Act_Action set ActionName=@ActionName,ActionValue=@ActionValue where ActionId = @ActionId", new
{
ActionName = "查询",
ActionValue = 8,
ActionId = "66307CAB-3394-4675-8FB3-5A8C90F6CD70"
});
Console.WriteLine("更新了 {0} 条数据", i);
```
## SqlServer连接配置
```
```
## Oracle连接配置
```
```