• 写一个system.data.entity的simpledatarepo,实现crudq这些功能,不需要引入entityframework,直接可以使用,用到objectset


    note:you can delete reference of entityframework when using this classes.it`s just a simple repohelper.the code below can also include a getpagedlist method when paging.
    have fun,it`s simple,just create edmx file from database.all one sentence.but when using iqueryable or transaction,you need to use context factory and develop your own methods.
    i am using it now.very simple.just like a static modelhelper orm.
    1.simpledaterepo:
    /*
     * author:iGo
     * for-free
     * last-update:2015年7月7日 
     * auth:mit
     * hope it will be useful to you
     * */
    using System;
    using System.Collections.Generic;
    using System.Data;
    using System.Linq;
    using System.Linq.Expressions;
    
    
    
    namespace DBContext {
        /// <summary>
        /// static data repo,you donot need to reference entity framework
        /// </summary>
        public class SimpleDataRepo {
            public static void Add<T>(T model) {
                if (model == null) return;
                using (var context = DataContext.Context) {
                    context.AddObject(typeof(T).Name, model);
                    context.SaveChanges();
                }
            }
    
            public static void Edit<T>(T model) where T : class {
                if (model == null) return;
                using (var context = DataContext.Context) {
                    context.AddObject(model.GetType().Name, model);
                    context.ObjectStateManager.ChangeObjectState(model, EntityState.Modified);
                    context.SaveChanges();
                }
            }
            public static void EditCommand<T>(String setCondition, String whereClause) {
                if (String.IsNullOrEmpty(setCondition)) return;
                using (var context = DataContext.Context) {
                    context.ExecuteStoreCommand(String.Format("update {0} set {1} where {2}", typeof(T).Name, setCondition, whereClause));
                }
            }
    
            public static void Delete<T>(T model) where T : class {
                if (model == null) return;
                using (var context = DataContext.Context) {
                    context.AddObject(model.GetType().Name, model);
                    context.ObjectStateManager.ChangeObjectState(model, EntityState.Deleted);
                    context.SaveChanges();
                }
    
            }
    
    
            [NotUsed("not used due to linq function unsupported!")]
            private static int GetPropertyIdValueFromModel<T>(T model) {
                return (int)model.GetType().GetProperty("id").GetValue(model, null);
            }
    
    
    
            public static IList<T> GetAll<T>(Expression<Func<T, bool>> condition = null) {
                using (var context = DataContext.Context) {
                    var query = context.GetType().GetProperty(typeof(T).Name).GetValue(context, null) as IQueryable<T>;
                    return query != null ? query.ToList() : null;
                }
            }
    
            public static IList<T> GetAllCommand<T>(String whereClause = "") {
                using (var context = DataContext.Context) {
                    return context.ExecuteStoreQuery<T>(String.Format("select * from {0} {1}", typeof(T).Name,
                         String.IsNullOrEmpty(whereClause) ? "" : (" where " + whereClause))).ToList();
                }
            }
    
    
            /// <summary>
            /// Get first model that satisfies the specified condition,GetById can be implied here,ie:a=>a.Id=5
            /// </summary>
            /// <typeparam name="T"></typeparam>
            /// <param name="condition"></param>
            /// <returns></returns>
            public static T QueryFirst<T>(Expression<Func<T, bool>> condition) {
                using (var context = DataContext.Context) {
                    var query = context.GetType().GetProperty(typeof(T).Name).GetValue(context, null) as IQueryable<T>;
                    if (query == null) return default(T);
                    return query.FirstOrDefault(condition);
                }
            }
    
            public static T QueryFirstCommand<T>(String condition = "") {
                using (var context = DataContext.Context) {
                    return
                        context.ExecuteStoreQuery<T>(String.Format("select top 1 * from {0} {1}", typeof(T).Name,
                            String.IsNullOrEmpty(condition) ? "" : (" where " + condition))).FirstOrDefault();
                }
            }
    
            public static IList<T> QuerySort<T, TS>(Expression<Func<T, bool>> condition, Expression<Func<T, TS>> sortExpression = null, bool isDecending = false) {
                using (var context = DataContext.Context) {
                    var query = context.GetType().GetProperty(typeof(T).Name).GetValue(context, null) as IQueryable<T>;
                    if (query == null) return null;
                    query = query.Where(condition).Where(condition);
                    if (sortExpression != null)
                        query = isDecending ? query.OrderByDescending(sortExpression) : query.OrderBy(sortExpression);
                    return query.ToList();
                }
            }
    
            public static void DeleteByIds<T>(String ids) {
                if (String.IsNullOrEmpty(ids)) throw new ArgumentException("ids cannot be null or empty!");
                using (var context = DataContext.Context) {
                    context.ExecuteStoreCommand(String.Format("delete from {0} where id in ({1})", typeof(T).Name, ids));
                    context.SaveChanges();
                }
            }
    
    
    
            #region web paging field
    
    
            //protected virtual IPagedList<T> GetTPagedList<T, TS>(Expression<Func<T, bool>> filter = null, Expression<Func<T, TS>> orderby = null, bool isDecending = false) where T : new() {
            //    IPagedList<T> list;
            //    using (var context = DataContext.Context) {
            //        var pageIndex = Request["pageNum"] ?? "1";
            //        var pageSize = Request["numPerPage"] ?? "15";
    
            //        Expression<Func<T, bool>> condition = a => true;
            //        if (filter != null) condition = condition.And(filter);
            //        var b = context.GetType().GetProperty(typeof(T).Name).GetValue(context, null) as IQueryable<T>;
            //        if (b == null) return null;
            //        b = b.Where(condition);
            //        if (orderby != null)
            //            b = !isDecending ? b.OrderBy(orderby) : b.OrderByDescending(orderby);
            //        list = b.ToPagedList(int.Parse(pageIndex), int.Parse(pageSize));
            //        //b.Skip(int.Parse(pageSize)*(int.Parse(pageIndex) - 1)).Take(int.Parse(pageSize)).ToList();
            //    }
            //    return list;
            //}
            #endregion
    
    
        }
    }
    
     
     2.context factory:
    using System;
    using System.Collections.Generic;
    using System.Data;
    using System.Data.Entity;
    using System.Linq;
    using System.Text;
    
    namespace DBContext {
        public partial class DataContext  {
            public static GpsDataContext Context {
                get {
                    return new GpsDataContext();
                }
            }
        }
    }
    
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  • 原文地址:https://www.cnblogs.com/hualiu0/p/4627726.html
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