dapper mysql 拓展_.net下开源轻量级ORM框架Dapper扩展系列1

轻量级ORM框架Dapper相信很多人了解，也用过，可能也有很多人可能还不知道

Dapper官网： https://code.google.com/p/dapper-dot-net/

我在网上复制一下别人对Dapper的描述：

Dapper是一个轻型的ORM类。代码就一个SqlMapper.cs文件。文件见下。编译后就40K的一个很小的Dll.

Dapper很快，有多快。实验下就知道了。官方给了点测试包，想玩的时候就去测试下。Dapper的速度接近与IDataReader，取列表的数据超过了DataTable。

Dapper支持什么数据库。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.

Dapper的r支持多表并联的对象。支持一对多 多对多的关系。并且没侵入性，想用就用，不想用就不用。无XML无属性。代码以前怎么写现在还怎么写。

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。

Dapper支持net2.0,3.0,3.5,4.0。

Dapper的语法是这样的。语法十分简单。并且无须迁就数据库的设计。

为什么要扩展Dapper：

了解Dapper都知道，在书写代码时，我们还是会手动写SQL，扩展的目的就是在完全不改变dapper源代码和使用基础上，进行一次封闭，达到零SQL，实现完全对象操作。

接下来，我们开始Dapper的扩展之旅第一章。。。

下载Dapper后，我们新建类库项目：DapperEx ,并把Dapper项目加载到项目中：

1.在DapperEx 中添加Dapper引用 ，如下：

2.为了存储数据库类型，以及根据数据库类型，使用不同的参数化操作数据库，添加一个DbBase类：

using System;

using System.Collections.Generic;

using System.Configuration;

using System.Data;

using System.Data.Common;

using System.Linq;

using System.Text;

namespace Dapper

{

public class DbBase : IDisposable

{

private string paramPrefix = "@";

private string providerName = "System.Data.SqlClient";

private IDbConnection dbConnecttion;

private DbProviderFactory dbFactory;

private DBType _dbType = DBType.SqlServer;

public IDbConnection DbConnecttion

{

get

{

return dbConnecttion;

}

}

public string ParamPrefix

{

get

{

return paramPrefix;

}

}

public string ProviderName

{

get

{

return providerName;

}

}

public DBType DbType

{

get

{

return _dbType;

}

}

public DbBase(string connectionStringName)

{

var connStr = ConfigurationManager.ConnectionStrings[connectionStringName].ConnectionString;

if (!string.IsNullOrEmpty(ConfigurationManager.ConnectionStrings[connectionStringName].ProviderName))

providerName = ConfigurationManager.ConnectionStrings[connectionStringName].ProviderName;

else

throw new Exception("ConnectionStrings中没有配置提供程序ProviderName！");

dbFactory = DbProviderFactories.GetFactory(providerName);

dbConnecttion = dbFactory.CreateConnection();

dbConnecttion.ConnectionString = connStr;

dbConnecttion.Open();

SetParamPrefix();

}

private void SetParamPrefix()

{

string dbtype = (dbFactory == null ? dbConnecttion.GetType() : dbFactory.GetType()).Name;

//使用类型名判断

if (dbtype.StartsWith("MySql")) _dbType = DBType.MySql;

else if (dbtype.StartsWith("SqlCe")) _dbType = DBType.SqlServerCE;

else if (dbtype.StartsWith("Npgsql")) _dbType = DBType.PostgreSQL;

else if (dbtype.StartsWith("Oracle")) _dbType = DBType.Oracle;

else if (dbtype.StartsWith("SQLite")) _dbType = DBType.SQLite;

else if (dbtype.StartsWith("System.Data.SqlClient.")) _dbType = DBType.SqlServer;

//else try with provider name

else if (providerName.IndexOf("MySql", StringComparison.InvariantCultureIgnoreCase) >= 0) _dbType = DBType.MySql;

else if (providerName.IndexOf("SqlServerCe", StringComparison.InvariantCultureIgnoreCase) >= 0) _dbType = DBType.SqlServerCE;

else if (providerName.IndexOf("Npgsql", StringComparison.InvariantCultureIgnoreCase) >= 0) _dbType = DBType.PostgreSQL;

else if (providerName.IndexOf("Oracle", StringComparison.InvariantCultureIgnoreCase) >= 0) _dbType = DBType.Oracle;

else if (providerName.IndexOf("SQLite", StringComparison.InvariantCultureIgnoreCase) >= 0) _dbType = DBType.SQLite;

if (_dbType == DBType.MySql && dbConnecttion != null && dbConnecttion.ConnectionString != null && dbConnecttion.ConnectionString.IndexOf("Allow User Variables=true") >= 0)

paramPrefix = "?";

if (_dbType == DBType.Oracle)

paramPrefix = ":";

}

public void Dispose()

{

if (dbConnecttion != null)

{

try

{

dbConnecttion.Dispose();

}

catch { }

}

}

}

public enum DBType

{

SqlServer,

SqlServerCE,

MySql,

PostgreSQL,

Oracle,

SQLite

}

}

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此类功能利用DbProviderFactories实现数据源连接接口IDbConnection，通过数据库判断设置参数前缀为@、？、：的一种。

3.和大多数实体映射一样，为了更方便的操作数据库，我们添加几个特性，来实现实体与数据库表的映射关系：

BaseAttribute：特性基类

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace Dapper

{

public class BaseAttribute:Attribute

{

///

///别名，对应数据里面的名字///

public string Name { get; set; }

}

}

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ColumnAttribute:字段列特性

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace Dapper

{

///

///列字段///

[AttributeUsage(AttributeTargets.Field | AttributeTargets.Property)]

public class ColumnAttribute : BaseAttribute

{

///

///自增长///

public bool AutoIncrement { get; set; }

public ColumnAttribute()

{

AutoIncrement = false;

}

///

///是否是自增长///

///

public ColumnAttribute(bool autoIncrement)

{

AutoIncrement = autoIncrement;

}

}

}

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IdAttribute:主键列特性

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace Dapper

{

///

///主键///

[AttributeUsage(AttributeTargets.Field | AttributeTargets.Property)]

public class IdAttribute : BaseAttribute

{

///

///是否为自动主键///

public bool CheckAutoId { get; set; }

public IdAttribute()

{

this.CheckAutoId = false;

}

///

///

///

/// 是否为自动主键

public IdAttribute(bool checkAutoId)

{

this.CheckAutoId = checkAutoId;

}

}

}

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IgnoreAttribute：忽略列特性

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace Dapper

{

///

///忽略字段///

[AttributeUsage(AttributeTargets.Field | AttributeTargets.Property)]

public class IgnoreAttribute:BaseAttribute

{

}

}

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TableAttribute：数据库表特性

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace Dapper

{

///

///数据库表///

[AttributeUsage(AttributeTargets.Field | AttributeTargets.Property)]

public class TableAttribute : BaseAttribute

{

}

}

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4.接下来建立一个生成SQL时参数里面的列名和对应值名称的对应类：ParamColumnModel

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace Dapper

{

///

///生成SQL时参数里面的列名和对应值名称///

public class ParamColumnModel

{

///

///数据库列名///

public string ColumnName { get; set; }

///

///对应类属性名///

public string FieldName { get; set; }

}

}

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5.建立一个公共类，方便对特性、属性进行操作和取值等操作Common

using Dapper;

using System;

using System.Collections.Generic;

using System.Linq;

using System.Linq.Expressions;

using System.Text;

using System.Text.RegularExpressions;

namespace DapperEx

{

public class Common

{

///

///获取对象对应数据库表名///

///

///

public static string GetTableName()

{

var ty = typeof(T);

var arri = ty.GetCustomAttributes(typeof(BaseAttribute), true).FirstOrDefault();

if (arri is TableAttribute && (!string.IsNullOrEmpty((arri as BaseAttribute).Name)))

{

return (arri as BaseAttribute).Name;

}

return ty.Name;

}

///

///在没有指定排序时，获取一个默认的排序列///

///

///

public static string GetDefaultOrderField()

{

var name = "";

foreach (var propertyInfo in typeof(T).GetProperties())

{

var arri = propertyInfo.GetCustomAttributes(typeof(BaseAttribute), true).FirstOrDefault();

if (arri is IgnoreAttribute)

{

arri = null;

continue;

}

name = (arri == null || string.IsNullOrEmpty((arri as BaseAttribute).Name)) ? propertyInfo.Name : (arri as BaseAttribute).Name;

break;

}

return name;

}

///

///获取要执行SQL时的列,添加和修改数据时///

///

///

public static IList GetExecColumns() where T : class

{

var columns = new List();

foreach (var propertyInfo in typeof(T).GetProperties())

{

var arri = propertyInfo.GetCustomAttributes(typeof(BaseAttribute), true).FirstOrDefault();

if (arri is IgnoreAttribute)

{

arri = null;

continue;

}

else if (arri is IdAttribute)

{

if ((arri as IdAttribute).CheckAutoId)

{

arri = null;

continue;

}

}

else if (arri is ColumnAttribute)

{

if ((arri as ColumnAttribute).AutoIncrement)

{

arri = null;

continue;

}

}

string name = (arri == null || string.IsNullOrEmpty((arri as BaseAttribute).Name)) ? propertyInfo.Name : (arri as BaseAttribute).Name;

columns.Add(new ParamColumnModel() { ColumnName = name, FieldName = propertyInfo.Name });

}

return columns;

}

///

///获取对象的主键标识列///

///

/// 对应实体属性名

///

public static string GetPrimaryKey(out string PropertyName) where T : class

{

string name = "";

PropertyName = "";

foreach (var propertyInfo in typeof(T).GetProperties())

{

var arri = propertyInfo.GetCustomAttributes(typeof(BaseAttribute), true).FirstOrDefault();

if (arri is IdAttribute)

{

name = (arri == null || string.IsNullOrEmpty((arri as BaseAttribute).Name)) ? propertyInfo.Name : (arri as BaseAttribute).Name;

PropertyName = propertyInfo.Name;

break;

}

}

if (string.IsNullOrEmpty(PropertyName))

{

throw new Exception("没有任何列标记为主键特性");

}

return name;

}

///

///通过属性名获取对应的数据列名///

///

///

///

public static string GetExecCloumName(string propertyName) where T : class

{

var propertyInfo = typeof(T).GetProperty(propertyName);

var arri = propertyInfo.GetCustomAttributes(typeof(BaseAttribute), true).FirstOrDefault();

if (arri is IgnoreAttribute)

{

arri = null;

}

string name = (arri == null || string.IsNullOrEmpty((arri as BaseAttribute).Name)) ? propertyInfo.Name : (arri as BaseAttribute).Name;

return name;

}

///

///通过表达示树获取属性名对应列名///

///

///

///

public static string GetNameByExpress(Expression> expr) where T : class

{

var pname = "";

if (expr.Body is UnaryExpression)

{

var uy = expr.Body as UnaryExpression;

pname = (uy.Operand as MemberExpression).Member.Name;

}

else

{

pname = (expr.Body as MemberExpression).Member.Name;

}

var propertyInfo = typeof(T).GetProperty(pname);

var arri = propertyInfo.GetCustomAttributes(typeof(BaseAttribute), true).FirstOrDefault();

if (arri is IgnoreAttribute)

{

throw new Exception(string.Format("{0}不能进行SQL处理", pname));

}

string name = (arri == null || string.IsNullOrEmpty((arri as BaseAttribute).Name)) ? propertyInfo.Name : (arri as BaseAttribute).Name;

return name;

}

///

///字符串中连续多个空格合并成一个空格///

///

///

public static string UnitMoreSpan(string str)

{

Regex replaceSpace = new Regex(@"\s{1,}", RegexOptions.IgnoreCase);

return replaceSpace.Replace(str, " ").Trim();

}

}

}

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6.有了以上基础，现在开始进行扩展操作，新建DapperEx类：

本系列，我们先扩展两个方法：添加一个实体 和 批量添加

代码比较简单：

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using Dapper;

using System.Data;

using DapperEx;

namespace Dapper

{

public static class DapperEx

{

///

///扩展插入数据///

///

///

///

///

///

///

///

public static bool Insert(this DbBase dbs, T t, bool useTransaction = false, int? commandTimeout = null) where T : class,new()

{

var db = dbs.DbConnecttion;

IDbTransaction tran = null;

if (useTransaction)

tran = db.BeginTransaction();

var result = false;

var tbName = Common.GetTableName();

var columns = Common.GetExecColumns();

var flag = db.Execute(CreateInertSql(tbName, columns, dbs.ParamPrefix), t, tran, commandTimeout);

if (tran != null)

{

try

{

tran.Commit();

result = true;

}

catch

{

tran.Rollback();

}

}

else

{

return flag == 1;

}

return result;

}

///

///批量插入///

///

///

///

///

///

///

public static bool InsertBatch(this DbBase dbs, IList lt, bool useTransaction = false, int? commandTimeout = null) where T : class,new()

{

var db = dbs.DbConnecttion;

IDbTransaction tran = null;

if (useTransaction)

tran = db.BeginTransaction();

var result = false;

var tbName = Common.GetTableName();

var columns = Common.GetExecColumns();

var flag = db.Execute(CreateInertSql(tbName, columns, dbs.ParamPrefix), lt, tran, commandTimeout);

if (tran != null)

{

try

{

tran.Commit();

result = true;

}

catch

{

tran.Rollback();

}

}

else

{

return flag == lt.Count;

}

return result;

}

///

///组装插入语句///

///

///

///

private static string CreateInertSql(string tbName, IList colums, string ParamPrefix)

{

StringBuilder sql = new StringBuilder();

sql.Append(string.Format("INSERT INTO {0}(", tbName));

for (int i = 0; i < colums.Count; i++)

{

if (i == 0) sql.Append(colums[i].ColumnName);

else sql.Append(string.Format(",{0}", colums[i].ColumnName));

}

sql.Append(")");

sql.Append("VALUES(");

for (int i = 0; i < colums.Count; i++)

{

if (i == 0) sql.Append(string.Format("{0}{1}", ParamPrefix, colums[i].FieldName));

else sql.Append(string.Format(",{0}{1}", ParamPrefix, colums[i].FieldName));

}

sql.Append(")");

return sql.ToString();

}

}

}

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今天要讲的都已经完成，接下来，我们进行使用测试：

在解决方案中添加一个测试库:DapperExTest,并在测试库中添加一个本地数据库：dbSqlCeEx.sdf，并在数据库中中添加一个表：Account

注意最后个一字段。Flag是一个字增长列.

在测试库中添加一个应用程序配置文件：App.config，并修改成自己相应的连接数据库字符串

在测试库中添加一个相应的实体类：Account

namespace DapperExTest

{

public class Account

{

[Id]

public virtual string Id { get; set; }

public virtual string Name { get; set; }

public virtual string Password { get; set; }

public virtual string Email { get; set; }

public virtual DateTime CreateTime { get; set; }

public virtual int Age { get; set; }

[Column(true)]

public virtual int Flag { get; set; }

[Ignore]

public virtual string AgeStr

{

get

{

return "年龄：" + Age;

}

}

}

}

上述工作完成后，在测试类UnitTest1中添加如下代码：

public string connectionName = "strSqlCe";

public DbBase CreateDbBase()

{

return new DbBase(connectionName);

}

现在我们对添加功能，进行测试，添加方法：

[TestMethod]

public void Insert()//插入一条数据

{

var model = new Account()

{

Id = "1",

Name = "张三1",

Password = "123456",

Email = "[email protected]",

CreateTime = DateTime.Now,

Age = 15

};

using (var db = CreateDbBase())

{

var result = db.Insert(model);

if (result)

Console.WriteLine("添加成功");

else

Console.WriteLine("添加失败");

}

}

右键运行测试，测试成功，成功添加一条数据：

现在测试批量添加：

[TestMethod]

public void InsertBatch()//插入多条数据

{

var list = new List();

for (int i = 2; i < 21; i++)

{

var model = new Account()

{

Id = i.ToString(),

Name = "张三" + i.ToString(),

Password = "123456",

Email = "[email protected]",

CreateTime = DateTime.Now,

Age = 15

};

list.Add(model);

}

using (var db = CreateDbBase())

{

var result = db.InsertBatch(list, true);

if (result)

Console.WriteLine("添加成功");

else

Console.WriteLine("添加失败");

}

}

运行完成后，查看数据库：

成功！！！

OK，

今天的扩展到此结束，后续系列将会对修改、批量修改、删除、批量删除、查询、分页进行扩展

希望大家多多关注，觉得对自己有所帮助或有意见的，欢迎留言，觉得不错的，不要吝啬你的鼠标，点点支持，点点推荐，谢谢啦！！！

本系列源码：http://pan.baidu.com/s/1dDh4T7F