扯淡
这是一款高质量的.NET C#数据库访问框架(ORM)。查询接口借鉴 Linq。借助 lambda 表达式，可以完全用面向对象的方式就能轻松执行多表连接查询、分组查询、聚合查询、插入数据、批量删除和更新等操作。
其实，早在两个月前，Chloe 就已经支持 Oracle 数据库了，只是LZ个人平时用 Oracle 不多，Oracle 较其他数据库稍微特别，因此，并没有及时发布，生怕 bug 连连。经过好几个月的沉淀，除了支持 Oracle 外，对框架内部代码结构也做了不少的调整，现在，实体也支持继承父类或接口，更加可喜可贺的是也支持了存储过程，包括 output 参数以及 Oracle 的 RefCurcor 返回结果集。与此同时，方便对 Chloe 的感兴趣的同学学习框架，官网也正式上线了。
导航
Chloe.ORM
事前准备
实体：
public enum Gender
{
Man = 1,
Woman
}
[Table("Users")]
public class User
{
[Sequence("USERS_AUTOID")]
public int Id { get; set; }
public string Name { get; set; }
public Gender? Gender { get; set; }
public int? Age { get; set; }
public int? CityId { get; set; }
public DateTime? OpTime { get; set; }
}
public class City
{
[Column(IsPrimaryKey = true)]
public int Id { get; set; }
public string Name { get; set; }
public int ProvinceId { get; set; }
}
public class Province
{
[Column(IsPrimaryKey = true)]
public int Id { get; set; }
public string Name { get; set; }
}
因为框架本身需要与具体的数据库驱动解耦，所以 OracleContext 构造函数需要一个 IDbConnectionFactory 的参数，IDbConnectionFactory 接口只有一个 CreateConnection() 方法，必须先建个类，实现 CreateConnection 方法：
public class OracleConnectionFactory : IDbConnectionFactory
{
string _connString = null;
public OracleConnectionFactory(string connString)
{
this._connString = connString;
}
public IDbConnection CreateConnection()
{
OracleConnection oracleConnection = new OracleConnection(this._connString);
OracleConnectionDecorator conn = new OracleConnectionDecorator(oracleConnection);
return conn;
}
}
由于我用的是 Oracle.ManagedDataAccess 数据库驱动，OracleConnection 创建的 DbCommand 默认是以顺序方式绑定参数，所以，上述例子使用了装饰者模式对 OracleConnection 封装了一遍，主要就是修改 DbCommand 参数绑定方式。OracleConnectionDecorator 的定义在官网API文档和 Github 上的 demo 中都有，在这就不贴了，不然太占篇幅。
创建一个 DbContext：
string connString = "Your connection string"; OracleContext context = new OracleContext(new OracleConnectionFactory(connString));
再创建一个 IQuery<T>：
IQuery<User> q = context.Query<User>();
查询数据
基本查询
IQuery<User> q = context.Query<User>();
q.Where(a => a.Id == 1).FirstOrDefault();
/*
* SELECT "USERS"."ID" AS "ID","USERS"."NAME" AS "NAME","USERS"."GENDER" AS "GENDER","USERS"."AGE" AS "AGE","USERS"."CITYID" AS "CITYID","USERS"."OPTIME" AS "OPTIME" FROM "USERS" "USERS" WHERE ("USERS"."ID" = 1 AND ROWNUM < 2)
*/
//可以选取指定的字段，支持返回匿名类型，也可以返回自定义类型
q.Where(a => a.Id == 1).Select(a => new { a.Id, a.Name }).FirstOrDefault();
/*
* SELECT "USERS"."ID" AS "ID","USERS"."NAME" AS "NAME" FROM "USERS" "USERS" WHERE ("USERS"."ID" = 1 AND ROWNUM < 2)
*/
//分页
q.Where(a => a.Id > 0).OrderBy(a => a.Age).TakePage(1, 20).ToList();
/*
* SELECT "T"."ID" AS "ID","T"."NAME" AS "NAME","T"."GENDER" AS "GENDER","T"."AGE" AS "AGE","T"."CITYID" AS "CITYID","T"."OPTIME" AS "OPTIME" FROM (SELECT "TTAKE"."ID" AS "ID","TTAKE"."NAME" AS "NAME","TTAKE"."GENDER" AS "GENDER","TTAKE"."AGE" AS "AGE","TTAKE"."CITYID" AS "CITYID","TTAKE"."OPTIME" AS "OPTIME",ROWNUM AS "ROW_NUMBER_0" FROM (SELECT "USERS"."ID" AS "ID","USERS"."NAME" AS "NAME","USERS"."GENDER" AS "GENDER","USERS"."AGE" AS "AGE","USERS"."CITYID" AS "CITYID","USERS"."OPTIME" AS "OPTIME" FROM "USERS" "USERS" WHERE "USERS"."ID" > 0 ORDER BY "USERS"."AGE" ASC) "TTAKE" WHERE ROWNUM < 21) "T" WHERE "T"."ROW_NUMBER_0" > 0
*/
连接查询
IQuery<User> users = context.Query<User>();
IQuery<City> cities = context.Query<City>();
IQuery<Province> provinces = context.Query<Province>();
//建立连接
IJoiningQuery<User, City> user_city = users.InnerJoin(cities, (user, city) => user.CityId == city.Id);
IJoiningQuery<User, City, Province> user_city_province = user_city.InnerJoin(provinces, (user, city, province) => city.ProvinceId == province.Id);
//查出一个用户及其隶属的城市和省份的所有信息，同样支持返回匿名类型，也可以返回自定义类型
var view = user_city_province.Select((user, city, province) => new { User = user, City = city, Province = province }).Where(a => a.User.Id == 1).ToList();
/*
* SELECT "USERS"."ID" AS "ID","USERS"."NAME" AS "NAME","USERS"."GENDER" AS "GENDER","USERS"."AGE" AS "AGE","USERS"."CITYID" AS "CITYID","USERS"."OPTIME" AS "OPTIME","CITY"."ID" AS "ID0","CITY"."NAME" AS "NAME0","CITY"."PROVINCEID" AS "PROVINCEID","PROVINCE"."ID" AS "ID1","PROVINCE"."NAME" AS "NAME1" FROM "USERS" "USERS" INNER JOIN "CITY" "CITY" ON "USERS"."CITYID" = "CITY"."ID" INNER JOIN "PROVINCE" "PROVINCE" ON "CITY"."PROVINCEID" = "PROVINCE"."ID" WHERE "USERS"."ID" = 1
*/
//也可以只获取指定的字段信息：UserId,UserName,CityName,ProvinceName，这时，生成的 sql 只包含指定的字段
user_city_province.Select((user, city, province) => new { UserId = user.Id, UserName = user.Name, CityName = city.Name, ProvinceName = province.Name }).Where(a => a.UserId == 1).ToList();
/*
* SELECT "USERS"."ID" AS "USERID","USERS"."NAME" AS "USERNAME","CITY"."NAME" AS "CITYNAME","PROVINCE"."NAME" AS "PROVINCENAME" FROM "USERS" "USERS" INNER JOIN "CITY" "CITY" ON "USERS"."CITYID" = "CITY"."ID" INNER JOIN "PROVINCE" "PROVINCE" ON "CITY"."PROVINCEID" = "PROVINCE"."ID" WHERE "USERS"."ID" = 1
*/
聚合函数
Chloe 的聚合查询拥有和 linq 差不多的接口，基本是一看就明白。
IQuery<User> q = context.Query<User>();
q.Select(a => AggregateFunctions.Count()).First();
/*
* SELECT COUNT(1) AS "C" FROM "USERS" "USERS" WHERE ROWNUM < 2
*/
q.Select(a => new { Count = AggregateFunctions.Count(), LongCount = AggregateFunctions.LongCount(), Sum = AggregateFunctions.Sum(a.Age), Max = AggregateFunctions.Max(a.Age), Min = AggregateFunctions.Min(a.Age), Average = AggregateFunctions.Average(a.Age) }).First();
/*
* SELECT COUNT(1) AS "COUNT",COUNT(1) AS "LONGCOUNT",SUM("USERS"."AGE") AS "SUM",MAX("USERS"."AGE") AS "MAX",MIN("USERS"."AGE") AS "MIN",AVG("USERS"."AGE") AS "AVERAGE" FROM "USERS" "USERS" WHERE ROWNUM < 2
*/
var count = q.Count();
/*
* SELECT COUNT(1) AS "C" FROM "USERS" "USERS"
*/
var longCount = q.LongCount();
/*
* SELECT COUNT(1) AS "C" FROM "USERS" "USERS"
*/
var sum = q.Sum(a => a.Age);
/*
* SELECT SUM("USERS"."AGE") AS "C" FROM "USERS" "USERS"
*/
var max = q.Max(a => a.Age);
/*
* SELECT MAX("USERS"."AGE") AS "C" FROM "USERS" "USERS"
*/
var min = q.Min(a => a.Age);
/*
* SELECT MIN("USERS"."AGE") AS "C" FROM "USERS" "USERS"
*/
var avg = q.Average(a => a.Age);
/*
* SELECT AVG("USERS"."AGE") AS "C" FROM "USERS" "USERS"
*/
分组查询
Chloe 的分组查询功能，可以像写 sql 一样支持 Having 和 Select。
IQuery<User> q = context.Query<User>();
IGroupingQuery<User> g = q.Where(a => a.Id > 0).GroupBy(a => a.Age);
g = g.Having(a => a.Age > 1 && AggregateFunctions.Count() > 0);
g.Select(a => new { a.Age, Count = AggregateFunctions.Count(), Sum = AggregateFunctions.Sum(a.Age), Max = AggregateFunctions.Max(a.Age), Min = AggregateFunctions.Min(a.Age), Avg = AggregateFunctions.Average(a.Age) }).ToList();
/*
* SELECT "USERS"."AGE" AS "AGE",COUNT(1) AS "COUNT",SUM("USERS"."AGE") AS "SUM",MAX("USERS"."AGE") AS "MAX",MIN("USERS"."AGE") AS "MIN",AVG("USERS"."AGE") AS "AVG" FROM "USERS" "USERS" WHERE "USERS"."ID" > 0 GROUP BY "USERS"."AGE" HAVING ("USERS"."AGE" > 1 AND COUNT(1) > 0)
*/
插入数据
方式1
以 lambda 表达式树的方式插入：
此种方式插入的好处是，可以指定列插入，就像写 sql 一样简单。
同时，该方式插入返回表主键值。如果实体主键是自增列（序列），返回值就会是自增值。
/* User 实体打了序列标签，会自动获取序列值。返回主键 Id */
int id = (int)context.Insert<User>(() => new User() { Name = "lu", Age = 18, Gender = Gender.Man, CityId = 1, OpTime = DateTime.Now });
/*
* SELECT "USERS_AUTOID"."NEXTVAL" FROM "DUAL"
* Int32 :P_0 = 14;
INSERT INTO "USERS"("NAME","AGE","GENDER","CITYID","OPTIME","ID") VALUES(N'lu',18,1,1,SYSTIMESTAMP,:P_0)
*/
方式2
以实体的方式插入：
该方式插入，如果一个实体存在自增列，会自动将自增列设置到相应的属性上。
User user = new User();
user.Name = "lu";
user.Age = 18;
user.Gender = Gender.Man;
user.CityId = 1;
user.OpTime = DateTime.Now;
//会自动将自增 Id 设置到 user 的 Id 属性上
user = context.Insert(user);
/*
* SELECT "USERS_AUTOID"."NEXTVAL" FROM "DUAL"
* Int32 :P_0 = 15;
String :P_1 = 'lu';
Int32 :P_2 = 1;
Int32 :P_3 = 18;
DateTime :P_4 = '2016/9/5 9:16:59';
INSERT INTO "USERS"("ID","NAME","GENDER","AGE","CITYID","OPTIME") VALUES(:P_0,:P_1,:P_2,:P_3,:P_2,:P_4)
*/
更新数据
方式1
以 lambda 表达式树的方式更新：
该方式解决的问题是：1.指定列更新；2.批量更新；3.支持类似 Age=Age + 100 这样更新字段。
context.Update<User>(a => a.Id == 1, a => new User() { Name = a.Name, Age = a.Age + 100, Gender = Gender.Man, OpTime = DateTime.Now });
/*
* UPDATE "USERS" SET "NAME"="USERS"."NAME","AGE"=("USERS"."AGE" + 100),"GENDER"=1,"OPTIME"=SYSTIMESTAMP WHERE "USERS"."ID" = 1
*/
//批量更新
//给所有女性年轻 10 岁
context.Update<User>(a => a.Gender == Gender.Woman, a => new User() { Age = a.Age - 10, OpTime = DateTime.Now });
/*
* UPDATE "USERS" SET "AGE"=("USERS"."AGE" - 10),"OPTIME"=SYSTIMESTAMP WHERE "USERS"."GENDER" = 2
*/
方式2
以实体的方式更新：
User user = new User(); user.Id = 1; user.Name = "lu"; user.Age = 28; user.Gender = Gender.Man; user.OpTime = DateTime.Now; context.Update(user); //会更新所有映射的字段 /* * String :P_0 = 'lu'; Int32 :P_1 = 1; Int32 :P_2 = 28; Nullable<Int32> :P_3 = NULL; DateTime :P_4 = '2016/9/5 9:20:07'; UPDATE "USERS" SET "NAME"=:P_0,"GENDER"=:P_1,"AGE"=:P_2,"CITYID"=:P_3,"OPTIME"=:P_4 WHERE "USERS"."ID" = :P_1 */ /* * 支持只更新属性值已变的属性 */ context.TrackEntity(user);//在上下文中跟踪实体 user.Name = user.Name + "1"; context.Update(user);//这时只会更新被修改的字段 /* * String :P_0 = 'lu1'; Int32 :P_1 = 1; UPDATE "USERS" SET "NAME"=:P_0 WHERE "USERS"."ID" = :P_1 */
删除数据
方式1
以 lambda 表达式树的方式删除：
context.Delete<User>(a => a.Id == 1); /* * DELETE FROM "USERS" WHERE "USERS"."ID" = 1 */ //批量删除 //删除所有不男不女的用户 context.Delete<User>(a => a.Gender == null); /* * DELETE FROM "USERS" WHERE "USERS"."GENDER" IS NULL */
方式2
以实体的方式删除：
User user = new User(); user.Id = 1; context.Delete(user); /* * Int32 :P_0 = 1; DELETE FROM "USERS" WHERE "USERS"."ID" = :P_0 */
存储过程
通过存储过程获取一个 User 信息：
Oracle 数据库中，如果一个存储过程需要返回结果集，需要借助 RefCursor output 参数特性。用法如下：
/* 必须先自定义 RefCursor 参数 */
OracleParameter p_cur = new OracleParameter();
p_cur.ParameterName = "p_cur";
p_cur.OracleDbType = OracleDbType.RefCursor;
p_cur.Direction = ParameterDirection.Output;
DbParam refCursorParam = new DbParam();
/* 将自定义 RefCursor 参数设置到 DbParam 的 ExplicitParameter 属性 */
refCursorParam.ExplicitParameter = p_cur;
DbParam id = new DbParam("id", 1);
User user = context.SqlQuery<User>("Proc_GetUser", CommandType.StoredProcedure, id，refCursorParam).FirstOrDefault();
通过存储过程的 output 参数获取一个用户的 name：
DbParam id = new DbParam("id", 1);
DbParam outputName = new DbParam("name", null, typeof(string)) { Direction = ParamDirection.Output };
context.Session.ExecuteNonQuery("Proc_GetUserName", CommandType.StoredProcedure, id, outputName);
支持函数
IQuery<User> q = context.Query<User>();
var space = new char[] { ' ' };
DateTime startTime = DateTime.Now;
DateTime endTime = startTime.AddDays(1);
var ret = q.Select(a => new
{
Id = a.Id,
String_Length = (int?)a.Name.Length,//LENGTH("USERS"."NAME")
Substring = a.Name.Substring(0),//SUBSTR("USERS"."NAME",0 + 1,LENGTH("USERS"."NAME"))
Substring1 = a.Name.Substring(1),//SUBSTR("USERS"."NAME",1 + 1,LENGTH("USERS"."NAME"))
Substring1_2 = a.Name.Substring(1, 2),//SUBSTR("USERS"."NAME",1 + 1,2)
ToLower = a.Name.ToLower(),//LOWER("USERS"."NAME")
ToUpper = a.Name.ToUpper(),//UPPER("USERS"."NAME")
IsNullOrEmpty = string.IsNullOrEmpty(a.Name),//too long
Contains = (bool?)a.Name.Contains("s"),//
Trim = a.Name.Trim(),//TRIM("USERS"."NAME")
TrimStart = a.Name.TrimStart(space),//LTRIM("USERS"."NAME")
TrimEnd = a.Name.TrimEnd(space),//RTRIM("USERS"."NAME")
StartsWith = (bool?)a.Name.StartsWith("s"),//
EndsWith = (bool?)a.Name.EndsWith("s"),//
/* oracle is not supported DbFunctions.Diffxx. */
//DiffYears = DbFunctions.DiffYears(startTime, endTime),//
//DiffMonths = DbFunctions.DiffMonths(startTime, endTime),//
//DiffDays = DbFunctions.DiffDays(startTime, endTime),//
//DiffHours = DbFunctions.DiffHours(startTime, endTime),//
//DiffMinutes = DbFunctions.DiffMinutes(startTime, endTime),//
//DiffSeconds = DbFunctions.DiffSeconds(startTime, endTime),//
//DiffMilliseconds = DbFunctions.DiffMilliseconds(startTime, endTime),//
//DiffMicroseconds = DbFunctions.DiffMicroseconds(startTime, endTime),//
/* ((CAST(:P_0 AS DATE)-CAST(:P_1 AS DATE)) * 86400000 + CAST(TO_CHAR(CAST(:P_0 AS TIMESTAMP),'ff3') AS NUMBER) - CAST(TO_CHAR(CAST(:P_1 AS TIMESTAMP),'ff3') AS NUMBER)) / 86400000 */
SubtractTotalDays = endTime.Subtract(startTime).TotalDays,//
SubtractTotalHours = endTime.Subtract(startTime).TotalHours,//...
SubtractTotalMinutes = endTime.Subtract(startTime).TotalMinutes,//...
SubtractTotalSeconds = endTime.Subtract(startTime).TotalSeconds,//...
SubtractTotalMilliseconds = endTime.Subtract(startTime).TotalMilliseconds,//...
AddYears = startTime.AddYears(1),//ADD_MONTHS(:P_0,12 * 1)
AddMonths = startTime.AddMonths(1),//ADD_MONTHS(:P_0,1)
AddDays = startTime.AddDays(1),//(:P_0 + 1)
AddHours = startTime.AddHours(1),//(:P_0 + NUMTODSINTERVAL(1,'HOUR'))
AddMinutes = startTime.AddMinutes(2),//(:P_0 + NUMTODSINTERVAL(2,'MINUTE'))
AddSeconds = startTime.AddSeconds(120),//(:P_0 + NUMTODSINTERVAL(120,'SECOND'))
//AddMilliseconds = startTime.AddMilliseconds(20000),//不支持
Now = DateTime.Now,//SYSTIMESTAMP
UtcNow = DateTime.UtcNow,//SYS_EXTRACT_UTC(SYSTIMESTAMP)
Today = DateTime.Today,//TRUNC(SYSDATE,'DD')
Date = DateTime.Now.Date,//TRUNC(SYSTIMESTAMP,'DD')
Year = DateTime.Now.Year,//CAST(TO_CHAR(SYSTIMESTAMP,'yyyy') AS NUMBER)
Month = DateTime.Now.Month,//CAST(TO_CHAR(SYSTIMESTAMP,'mm') AS NUMBER)
Day = DateTime.Now.Day,//CAST(TO_CHAR(SYSTIMESTAMP,'dd') AS NUMBER)
Hour = DateTime.Now.Hour,//CAST(TO_CHAR(SYSTIMESTAMP,'hh24') AS NUMBER)
Minute = DateTime.Now.Minute,//CAST(TO_CHAR(SYSTIMESTAMP,'mi') AS NUMBER)
Second = DateTime.Now.Second,//CAST(TO_CHAR(SYSTIMESTAMP,'ss') AS NUMBER)
Millisecond = DateTime.Now.Millisecond,//CAST(TO_CHAR(SYSTIMESTAMP,'ff3') AS NUMBER)
DayOfWeek = DateTime.Now.DayOfWeek,//(CAST(TO_CHAR(SYSTIMESTAMP,'D') AS NUMBER) - 1)
Int_Parse = int.Parse("1"),//CAST(N'1' AS NUMBER)
Int16_Parse = Int16.Parse("11"),//CAST(N'11' AS NUMBER)
Long_Parse = long.Parse("2"),//CAST(N'2' AS NUMBER)
Double_Parse = double.Parse("3"),//CAST(N'3' AS BINARY_DOUBLE)
Float_Parse = float.Parse("4"),//CAST(N'4' AS BINARY_FLOAT)
Decimal_Parse = decimal.Parse("5"),//CAST(N'5' AS NUMBER)
//Guid_Parse = Guid.Parse("D544BC4C-739E-4CD3-A3D3-7BF803FCE179"),//不支持
Bool_Parse = bool.Parse("1"),//
DateTime_Parse = DateTime.Parse("1992-1-16"),//TO_TIMESTAMP(N'1992-1-16','yyyy-mm-dd hh24:mi:ssxff')
B = a.Age == null ? false : a.Age > 1,
}).ToList();
坎坎坷坷
支持 Oracle，一开始我是拒(畏)绝(惧)的，这货太奇葩了- -。后来想想，反正迟早都得要支持，干脆把它给干了吧，免得“夜长梦多”！不过 Oracle 是真奇葩，烦！比如，Oracle 不能直接在存储过程里直接执行 Select sql 返回结果集，必须得依赖它那个神马 RefCurcor 参数，这个我真的万万没想到，后来一位园友提醒了才留意这个特性！ 再一个，Oracle 不支持 bool 类型，Oracle.ManagedDataAccess 这个驱动的 DataReader 也不支持 GetBoolean 方法，同时 Oracle.ManagedDataAccess 创建的 DbCommand 默认是是以顺序方式绑定参数，因此，又不得不对 DataReader 和 DbCommand 包装一遍才能用。如果真的要细数起来，Oracle 的糟点连起来估计能绕地球一圈！
结语
把 Oracle 给支持了，心中的石头也终于落下，生活轻松了许多。作为众多 ORM 中为数不多能支持 Oracle 的一枚成员，感兴趣的可以关注一波。或许，Chloe 真能给你带来不一样的感觉！更多详细用法敬请参照官网API文档。
技术教程或心得我倒不是很擅长写，我只想把日常开发的一些干货分享给大家，您的推荐是我分享的最大动力。如果觉得 Chloe 这个开源项目不错，望大家给个赞，也可以上 Github 关注或收藏(star)一下，以便能及时收到更新通知。同时，Chloe 官网以及基于 NFine 改造的后台后续也会放出，有期待的同学可以点个关注，也欢迎广大C#同胞入群交流，畅谈.NET复兴大计。最后，感谢大家阅读至此！
Chloe.ORM 完全开源，遵循 Apache2.0 协议，托管于 GitHub，地址：https://github.com/shuxinqin/Chloe。