EntityFramework DB操作帮助类

using LSALogger;
using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Data.Entity.Core;
using System.Data.Entity.Core.Metadata.Edm;
using System.Data.Entity.Core.Objects;
using System.Diagnostics;
using System.Linq;
using System.Linq.Expressions;
using System.Reflection;
using System.Text;

namespace LSADataAccess
{
public class DataAccessorHelper
{
private readonly static string formatString = typeof(DataAccessorHelper).FullName;

    #region Select Method    /// <summary>    /// Select Single    /// </summary>    /// <typeparam name="T"></typeparam>    /// <param name="selector"></param>    /// <returns></returns>    public T SelectSingle<T>(Func<T, bool> selector = null) where T : class    {        T result = null;        try        {            using (DataAccessorEntities context = new DataAccessorEntities())            {                if (selector == null)                {                    result = context.Set<T>().FirstOrDefault();                }                else                {                    result = context.Set<T>().FirstOrDefault(selector);                }            }        }        catch (Exception ex)        {            PrintExceptionLog(ex);        }        return result;    }    /// <summary>    /// Select Single Join Table    /// </summary>    /// <typeparam name="T"></typeparam>    /// <param name="selector"></param>    /// <param name="includePath"></param>    /// <returns></returns>    public T SelectSingle<T>(Func<T, bool> selector, string includePath) where T : class    {        T result = null;        try        {            using (DataAccessorObjectEntities context = new DataAccessorObjectEntities())            {                result = context.CreateObjectSet<T>()                    .Include(includePath)                    .Where(selector)                    .FirstOrDefault();            }        }        catch (Exception ex)        {            PrintExceptionLog(ex);        }        return result;    }    /// <summary>    /// Select Single Join Tables    /// </summary>    /// <typeparam name="T"></typeparam>    /// <param name="selector"></param>    /// <param name="includePaths"></param>    /// <returns></returns>    public T SelectSingle<T>(Func<T, bool> selector, string[] includePaths) where T : class    {        T result = null;        try        {            using (DataAccessorObjectEntities context = new DataAccessorObjectEntities())            {                ObjectQuery<T> query = context.CreateObjectSet<T>().Where("1==1");                if (includePaths != null && includePaths.Count() > 0)                {                    foreach (string path in includePaths)                    {                        query = query.Include(path);                    }                }                result = query.FirstOrDefault(selector);            }        }        catch (Exception ex)        {            PrintExceptionLog(ex);        }        return result;    }    /// <summary>    /// Select All    /// </summary>    /// <typeparam name="T"></typeparam>    /// <returns></returns>    public IEnumerable<T> Select<T>() where T : class    {        try        {            using (DataAccessorObjectEntities context = new DataAccessorObjectEntities())            {                return context.CreateObjectSet<T>().ToList();            }        }        catch (Exception ex)        {            PrintExceptionLog(ex);            return null;        }    }    /// <summary>    /// Select Collection    /// </summary>    /// <typeparam name="T"></typeparam>    /// <param name="selector"></param>    /// <returns></returns>    public IEnumerable<T> Select<T>(Func<T, bool> selector) where T : class    {        IEnumerable<T> result = null;        try        {            using (DataAccessorEntities context = new DataAccessorEntities())            {                result = context.Set<T>().Where(selector).ToList();            }        }        catch (Exception ex)        {            PrintExceptionLog(ex);        }        return result;    }    /// <summary>    /// Select Collection Join Table    /// </summary>    /// <typeparam name="T"></typeparam>    /// <param name="selector"></param>    /// <param name="include"></param>    /// <returns></returns>    public IEnumerable<T> Select<T>(Func<T, bool> selector, string include) where T : class    {        IEnumerable<T> result = null;        try        {            using (DataAccessorObjectEntities context = new DataAccessorObjectEntities())            {                ObjectQuery<T> query = context.CreateObjectSet<T>().Where("1==1");                var data = context.CreateObjectSet<T>()                    .Include(include)                    .Where(selector);                result = data.ToList();            }        }        catch (Exception ex)        {            PrintExceptionLog(ex);        }        return result;    }    /// <summary>    /// Select Collection Join Tables    /// </summary>    /// <typeparam name="T"></typeparam>    /// <param name="selector"></param>    /// <param name="includes"></param>    /// <returns></returns>    public IEnumerable<T> Select<T>(Func<T, bool> selector, string[] includes) where T : class    {        IEnumerable<T> result = null;        try        {            using (DataAccessorObjectEntities context = new DataAccessorObjectEntities())            {                ObjectQuery<T> query = context.CreateObjectSet<T>().Where("1==1");                if (includes != null && includes.Count() > 0)                {                    foreach (string path in includes)                    {                        query = query.Include(path);                    }                }                result = query.Where(selector).ToList();            }        }        catch (Exception ex)        {            PrintExceptionLog(ex);        }        return result;    }    #endregion    #region Insert Method    /// <summary>    /// Insert Single    /// </summary>    /// <typeparam name="T"></typeparam>    /// <param name="entity"></param>    /// <returns></returns>    public int Insert<T>(T entity) where T : class    {        try        {            using (DataAccessorObjectEntities context = new DataAccessorObjectEntities())            {                context.CreateObjectSet<T>().AddObject(entity);                return context.SaveChanges(SaveOptions.AcceptAllChangesAfterSave);            }            #region other way            //using (DataAccessorEntities context = new DataAccessorEntities())            //{            //    context.Set<T>().Add(entity);            //    return context.SaveChanges();            //}            #endregion        }        catch (Exception ex)        {            PrintExceptionLog(ex);            return -1;        }    }    /// <summary>    /// Insert Collection    /// </summary>    /// <typeparam name="T"></typeparam>    /// <param name="entities"></param>    /// <returns></returns>    public int Insert<T>(IEnumerable<T> entities) where T : class    {        try        {            using (DataAccessorEntities context = new DataAccessorEntities())            {                context.Set<T>().AddRange(entities);                return context.SaveChanges();            }        }        catch (Exception ex)        {            PrintExceptionLog(ex);            return -1;        }    }    #endregion    #region Update Method    /// <summary>    /// Update Single    /// </summary>    /// <typeparam name="T"></typeparam>    /// <param name="entity"></param>    /// <returns></returns>    public int Update<T>(T entity) where T : class    {        try        {            using (DataAccessorObjectEntities context = new DataAccessorObjectEntities())            {                ObjectSet<T> objectSet = context.CreateObjectSet<T>();                objectSet.Attach(entity);                context.ObjectStateManager.ChangeObjectState(entity, System.Data.Entity.EntityState.Modified);                return context.SaveChanges(SaveOptions.AcceptAllChangesAfterSave);            }            #region other way            //using (DataAccessorEntities context = new DataAccessorEntities())            //{            //    context.Entry<T>(entity).State = System.Data.Entity.EntityState.Modified;            //    return context.SaveChanges();            //}            #endregion        }        catch (Exception ex)        {            PrintExceptionLog(ex);            return -1;        }    }    /// <summary>    /// Update Collection    /// See better way: https://github.com/loresoft/EntityFramework.Extended    /// NuGet: https://www.nuget.org/packages/EntityFramework.Extended    /// </summary>    /// <typeparam name="T"></typeparam>    /// <param name="entities"></param>    /// <returns></returns>    public int Update<T>(IEnumerable<T> entities) where T : class    {        try        {            using (DataAccessorEntities context = new DataAccessorEntities())            {                foreach (var item in entities)                {                    context.Entry<T>(item).State = EntityState.Modified;                }                return context.SaveChanges();            }        }        catch (Exception ex)        {            PrintExceptionLog(ex);            return -1;        }    }    #endregion    #region Delete Method    public int Delete<T>(T entity) where T : class    {        try        {            using (DataAccessorEntities context = new DataAccessorEntities())            {                context.Entry<T>(entity).State = EntityState.Deleted;                return context.SaveChanges();            }        }        catch (Exception ex)        {            PrintExceptionLog(ex);            return -1;        }    }    /// <summary>    /// Delete Collection    /// </summary>    /// <typeparam name="T"></typeparam>    /// <param name="entities"></param>    /// <returns></returns>    public int Delete<T>(IEnumerable<T> entities) where T : class    {        try        {            using (DataAccessorEntities context = new DataAccessorEntities())            {                DbSet<T> dbSet = context.Set<T>();                foreach (var item in entities)                {                    dbSet.Attach(item);                }                dbSet.RemoveRange(entities);                return context.SaveChanges();            }        }        catch (Exception ex)        {            PrintExceptionLog(ex);            return -1;        }    }    public int Delete<T>(Func<T, bool> selector) where T : class    {        try        {            using (DataAccessorEntities context = new DataAccessorEntities())            {                IEnumerable<T> deleteData = context.Set<T>().Where(selector);                foreach (var item in deleteData)                {                    context.Set<T>().Attach(item);                }                context.Set<T>().RemoveRange(deleteData);                return context.SaveChanges();            }        }        catch (Exception ex)        {            PrintExceptionLog(ex);            return -1;        }    }    #endregion    #region Other Method    /// <summary>    /// Whether the specified object exists    /// </summary>    /// <typeparam name="T"></typeparam>    /// <param name="selector"></param>    /// <returns>-1:Exception, 1: Existed, 0: Not Exist</returns>    public int IsExists<T>(Func<T, bool> selector) where T : class    {        try        {            using (DataAccessorEntities context = new DataAccessorEntities())            {                return context.Set<T>().Where(selector).Count() > 0 ? 1 : 0;            }        }        catch (Exception ex)        {            PrintExceptionLog(ex);            return -1;        }    }    /// <summary>    /// Whether the specified object exists    /// </summary>    /// <typeparam name="T"></typeparam>    /// <param name="entity"></param>    /// <returns>-1:Exception, 1: Existed, 0: Not Exist</returns>    public int IsExists<T>(T entity) where T : class    {        try        {            using (DataAccessorObjectEntities context = new DataAccessorObjectEntities())            {                object value;                var entityKeyValues = new List<KeyValuePair<string, object>>();                EntitySet entitySet = context.CreateObjectSet<T>().EntitySet;                foreach (var member in entitySet.ElementType.KeyMembers)                {                    var info = entity.GetType().GetProperty(member.Name);                    var tempValue = info.GetValue(entity, null);                    var pair = new KeyValuePair<string, object>(member.Name, tempValue);                    entityKeyValues.Add(pair);                }                var key = new EntityKey(entitySet.EntityContainer.Name + "." + entitySet.Name, entityKeyValues);                if (context.TryGetObjectByKey(key, out value))                {                    return value != null ? 1 : 0;                }            }        }        catch (Exception ex)        {            PrintExceptionLog(ex);        }        return -1;    }    /// <summary>    ///     /// </summary>    /// <typeparam name="T"></typeparam>    /// <param name="selector"></param>    /// <param name="maxfunc"></param>    /// <returns></returns>    public object Max<T>(Func<T, bool> selector, Func<T, object> maxfunc) where T : class    {        object result = null;        try        {            using (DataAccessorEntities context = new DataAccessorEntities())            {                result = context.Set<T>().Where(selector).Max(maxfunc);            }        }        catch (Exception ex)        {            PrintExceptionLog(ex);        }        return result;    }    #endregion    #region Private Method    /// <summary>    /// Print Exception Log Info    /// </summary>    /// <param name="ex"></param>    private void PrintExceptionLog(Exception ex)    {        StackTrace trace = new StackTrace();        MethodBase method = trace.GetFrame(1).GetMethod();        LogHelper.Instance.Error(string.Format("{0}::{1} - Exception:", formatString, method), ex);    }    #endregion}

}