软件简介

easy4net是一个轻量级orm框架，灵活在于可以自己编写复杂的SQL语句查询，简单在于几分钟内便能上手使用，并支持mysql, mssql,
oracle, access数据库.

详细文档地址：http://git.oschina.net/wangwei123/easy4net/wikis/easy4net

代码生成器：http://www.oschina.net/p/entitycodebuilder

分页查询：

1. 命名参数， ParamMap传参方式：
2. 支持多层嵌套查询自动分页功能。

int pageIndex = 1; 
int pageSize = 3; 
string sql = "SELECT * FROM (select * from student where age < @age 
or address= @address) as v"; 
ParamMap param = ParamMap.newMap(); 
param.setParameter("age",24); 
param.setParameter("address", "上海市"); param.setPageIndex(pageIndex); 
param.setPageSize(pageSize); 
List<Student> student = DB.FindBySql<Student>(sql, param);

分页查询：

int pageIndex = 1; 
int pageSize = 3; 
string sql = "SELECT * FROM student WHERE age < 28"; 
List<Student> list1 = DB.FindBySql<Student>(sql , pageIndex, pageSize);

更多查询方式：

**//查询所有 
List list = DB.FindAll(); 
//通过ID主键查询 
Student student = DB.FindById <Student>(5); 
//通过SQL语句查询 
List<Student> list1 = DB.FindBySql<Student>("SELECT * FROM U_Student WHERE U_Age < 28"); 
//查询某个字段 
List<Student> list2 = DB.FindByProperty<Student>("U_Name", "Lily Mary"); 
// 通过自定义条件查询
// SELECT xxx FROM U_Student WHERE U_Name LIKE '%Lily%' OR U_Age < 28 DbCondition cond1 = new DbCondition().Where().Like("U_Name", "Lily").OrLessThan( "U_Age", 28); 
List<Student> list3 = DB.Find<Student>(cond1); 
// 多表关联查询 
DbCondition cond2 = new DbCondition("SELECT s.*,c.teacher,c.className FROM U_Student s " "INNER JOIN U_Class c ON s.classID = c.ID").Where().RightLike("U_Name","Lil"); List<Student> list4 = DB.Find<Student>(cond2); 
//通过条件查询数量
//SELECT count(0) FROM U_Student WHERE U_Name = 'Lily Mary' AND U_Age = 28 
DbCondition cond3 = new DbCondition().Where("U_Name", "Andy").And("U_Age", 28); int count = DB.FindCount<Student>(cond3); **

**

新增：

1. 新增后返回新增记录的主键id值
2. 主键id值已经自动填充到新增的对象entity中

DBHelper db = DBHelper.getInstance(); 
Student entity = new Student(); 
entity.Name = "Lily"; 
entity.Gender = "女"; 
entity.Age = 23; 
entity.Address = "上海市徐汇区中山南二路918弄"; 
int id = db.Save(entity);

**

修改：

**Student entity = new Student(); 
entity.UserID = 1; 
entity.Name = "Andy"; 
entity.Age = 22; db.Update(entity);**

删除：
1. 按对象方式删除数据
2. 按主键id方式删除数据

Student student = m_stuList[i]; 
//remove a object 
db.Remove(student); 
//remove by id 
db.Remove(student.UserID);

数据库与C#对象映射关系配置：

**[Serializable] 
[Table(Name = "U_Student")] 
public class Student { 
    //主键自增长  
    [Id(Name = "UserID", Strategy = GenerationType.INDENTITY)] 
    public int UserID { get; set; }

    //数据库字段U_Name  
    [Column(Name = "U_Name")] 
    public string Name { get; set; }

    [Column(Name = "U_Age")] 
    // int? 允许int类型为空  
    public int? Age { get; set; }

    [Column(Name = "U_Gender")] 
    public string Gender { get; set; }

    [Column(Name = "U_Address")] 
    public string Address { get; set; }

    [Column(Name = "U_CreateTime")] 
    public DateTime? CreateTime { get; set; }

    [Column(Name = "ClassID")] 
    public int? ClassID { get; set; }

    // 不保存该属性值到数据库库，忽略新增和修改  
    [Column(Name = "ClassName",IsInsert=false,IsUpdate=false)] 
    public string ClassName { get; set; }

    // 不保存该属性值到数据库库，忽略新增和修改  
    [Column(Name = "Teacher", IsInsert = false, IsUpdate = false)]                        public string Teacher { get; set; } 
} 
}**

数据库连接配置 web.config中：

dbType中配置sqlserver, mysql, oracle来支持不同的数据库

**< configuration> 
    <appSettings> 
        <add key="DbType" value="sqlserver"/> 
        <add key="connectionString" value="Data Source=127.0.0.1;Initial Catalog=test;User ID=test;Password=test123;Trusted_Connection=no;Min Pool Size=10;Max Pool Size=100;"/> 
    <!--<add key="DbType" value="mysql"/>
        <add key="connectionString" value="Data Source=127.0.0.1;port=8001;User ID=test;Password=123456;DataBase=test;Min Pool Size=10;Max Pool Size=100;"/>--> 
    </appSettings> 
</configuration> **