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一、ORM入口封装
结合上一篇文章与这里的DbProvider().Init()方法,就很明显的知道了是创建一个mssql的实例。那么在DbService的泛型方法中显示提供了单表操作与多表linq查询的入口,其实还存在获取数据库扩展操作的入口。
public class DbService { /// <summary> /// 默认业务数据库的Provider /// </summary> public static IDbProvider DefaultProvider { get { return new DbProvider().Init(new DbConnInfo() { CommandTimeout = 60, ConnectionString = "Data Source = 127.0.0.1;Initial Catalog =DapperData;uid=sa;pwd=sa123456;", Provider = ProviderInfo.SqlServer, DbKey = "DapperData" }); } } } public class DbService<T> where T : class,new() { /// <summary> /// 默认数据库的DAL /// </summary> public static IReqository<T> Reqository { get { return DbService.DefaultProvider.GetReqository<T>(); } } /// <summary> /// 主库指定类型的查询接口,是Linq的入口 /// </summary> public static IQuery<T> Query { get { return DbService.DefaultProvider.GetQuery<T>(); } } }
二、单表、多表、扩展示例
A、单表
DbService<UserEntity>.Reqository.Single(w => w.Email.Contains("@")); DbService<UserEntity>.Reqository.Insert(new UserEntity(){}); DbService<UserEntity>.Reqository.Update(up => new UserEntity{Email = "taibai@xingguangju.com"}, wh => wh.UserId == 4); DbService<UserRoleEntity>.Reqository.Delete(w => w.Id == 4);
B、多表连个查询
var resultList = (from u in DbService<UserEntity>.Query join ur in DbService<UserRoleEntity>.Query on new {u = u.UserId, a = u.IsActive} equals new {u = ur.UserId, a = ur.IsActive} join r in DbService<RoleEntity>.Query on ur.RoleId equals r.RoleId where u.UserId == 1 orderby u.UserId select new UUR { UserId = u.UserId, Username = u.Username, PhoneNumber = u.PhoneNumber, RoleName = r.RoleName }).SetJoinMode(JoinMode.Inner, JoinMode.Inner).Page(1,1); var result = resultList.ToList().FirstOrDefault();
C、分组查询
//select CICUser.UserId, // MAX([CICUserScore].[score]) //from [CICUser] Join [CICUserScore] on [CICUser].[UserId] = [CICUserScore].[UserId] //group by CICUser.UserId having (SUM(CICUserScore.score) > 200) var resultList = (from a in DbService<UserEntity>.Query join b in DbService<UserScoreEntity>.Query on a.UserId equals b.UserId group new {a, b} by new {a.UserId} into g where g.Sum(m=>m.b.score)>200 select new { userId= g.Key.UserId, TotalScore = g.Max(b => b.b.score) }).ToList();
D、存储过程
var dbParameters = new DbParameterCollection(); dbParameters.Add(new DbParameter { DbType = DbType.Int32, Name = "UserId", Value =1, Direction = ParameterDirection.Input }); var resultList = DbService.DbExtension.ExcuteProcReader<UserEntity>("GetUserData", dbParameters);
E、事务
using (var dbprovider = DbService.DefaultProvider) { try { dbprovider.Begin(); dbprovider.GetReqository<UserScoreEntity>().Insert(new UserScoreEntity { Id = Guid.NewGuid().ToString(), score = 666, UserId = 4 }); dbprovider.GetReqository<UserRoleEntity>().Insert(new UserRoleEntity { Id = 8, UserId = 4, RoleId = 2, IsActive = false }); dbprovider.Commit(); } catch (Exception) { dbprovider.Rollback(); } }
F、执行Sql语句
var ds = DbService.DbExtension.ExcuteQuery("select * from dbo.CICUser"); foreach (DataRow row in ds.Tables[0].Rows) { Console.WriteLine(row[0]); }
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原文地址:http://www.cnblogs.com/wucj/p/4999386.html