Entity Framework底层操作封装V2版本号（1）

由于同志们一直给我提建议说。曾经发的版本号有问题。所以经过了我这一年多的使用和扩展，如今方法基本稳定了。

如今贴出来给大家使用：

首先上场的是数据库操作层：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Linq.Expressions;
using System.Data.Objects.DataClasses;
using System.Reflection;
using JFrame.Utility;
namespace JFrame.AccessCommon
{
    public class AccessBase<T> where T : EntityObject
    {
        protected string _TableName;
        protected string _QueryColums;
        protected string _PrimaryKey;
        protected Type _PrimaryKeyType;

        /// <summary>
        /// 运行数据库操作基础类方法
        /// </summary>
        protected DataCommon Data;

        /// <summary>
        /// 实例化操作对象
        /// </summary>
        /// <param name="ConnectionString">EF连接字符串</param>
        /// <param name="PrimaryKey">主键</param>
        /// <param name="strTableName">表名</param>
        /// <param name="QueryColums">查询的列</param>
        /// <param name="IsEntityData">是否为ADO实体对象</param>
        public AccessBase(string ConnectionString, string PrimaryKey = "", string strTableName = "", string QueryColums = "")
        {
            Data = new DataCommon(ConnectionString);
            Type t = typeof(T);
            if (string.IsNullOrEmpty(strTableName))
            {
                strTableName = t.Name; //GetType(t).ToString();
            }
            _TableName = strTableName;
            if (string.IsNullOrEmpty(QueryColums))
            {
                _QueryColums = " * ";
            }

            if (string.IsNullOrEmpty(PrimaryKey))
            {
                PropertyInfo[] infos = t.GetProperties();
                PrimaryKey = GetPrimaryKey(infos);
            }
            _PrimaryKey = PrimaryKey;
        }

        /// <summary>
        /// 获取主键
        /// </summary>
        /// <param name="infos"></param>
        /// <param name="IsEdmScalarPropertyAttribute"></param>
        /// <returns></returns>
        private string GetPrimaryKey(PropertyInfo[] infos)
        {
            string columnName = string.Empty;
            foreach (PropertyInfo propertyInfo in infos)
            {
                object[] customInfos = propertyInfo.GetCustomAttributes(typeof(EdmScalarPropertyAttribute), true);
                if (customInfos == null
               || customInfos.Length == 0)
                    return string.Empty;

                EdmScalarPropertyAttribute limit = customInfos.GetValue(0) as EdmScalarPropertyAttribute;
                if (limit.EntityKeyProperty)
                {
                    _PrimaryKeyType = propertyInfo.PropertyType;
                    return columnName = propertyInfo.Name;
                }
            }
            return columnName;

        }

        /// <summary>
        /// 添加单个实体
        /// </summary>
        /// <param name="t"></param>
        public virtual void AddEntity(T t)
        {
            Data.InsertEntity<T>(t);
        }

        /// <summary>
        /// 获取单个实体
        /// </summary>
        /// <param name="query">查询条件</param>
        /// <returns></returns>
        public virtual T GetSingleEntity(Expression<Func<T, bool>> query)
        {
            return Data.GetSingleEntity<T>(query);
        }

        public virtual List<T> GetAllEntityByPage(Expression<Func<T, bool>> query,PagingInfo PageInfo, Func<T, object> orderByDesc)
        {
           return Data.GetAllEntity<T>(query, PageInfo,  orderByDesc);
        }

        /// <summary>
        /// 获取单个实体
        /// </summary>
        /// <typeparam name="T">泛型类型參数</typeparam>
        /// <param name="express">查询条件</param>
        /// <returns></returns>
        public virtual T TryGetSingleEntity(Expression<Func<T, bool>> query)
        {
            try
            {
                return Data.GetSingleEntity<T>(query);
            }
            catch (Exception ex)
            {
                return null;
            }
        }

        /// <summary>
        /// 依据条件获取单个实体
        /// </summary>
        /// <param name="query">查询条件</param>
        /// <returns>实体对象</returns>
        public virtual T GetSingleEntity(string query)
        {
            return GetListByWhere(query).FirstOrDefault();
        }

        /// <summary>
        /// 依据主键获取对象
        /// </summary>
        /// <param name="PrimaryKeyValue">主键值</param>
        /// <returns>对象</returns>
        public virtual T GetSingleEntity(object PrimaryKeyValue)
        {
            StringBuilder strWhere = new StringBuilder();
            switch (_PrimaryKeyType.Name.ToLower())
            {
                case "int16":
                case "int32":
                case "int64":
                case "int":
                case "decimal":
                case "double":
                case "float":
                case "short":
                    strWhere.AppendFormat(" {0}={1}", _PrimaryKey, PrimaryKeyValue);
                    break;
                case "bool":
                case "boolean":
                    if ((bool)PrimaryKeyValue)
                    { strWhere.AppendFormat(" {0}=1", _PrimaryKey); }
                    else
                    { strWhere.AppendFormat(" {0}=0", _PrimaryKey); }

                    break;
                default:
                    strWhere.AppendFormat(" {0}='{1}'", _PrimaryKey, PrimaryKeyValue);
                    break;
            }

            return GetListByWhere(strWhere.ToString()).FirstOrDefault();
        }

        /// <summary>
        /// 改动单个实体
        /// </summary>
        /// <param name="t"></param>
        public virtual void UpdateEntity(T t)
        {
            Type type = typeof(T);
            PropertyInfo[] infos = type.GetProperties();
            PropertyInfo info = infos.Where(p => p.Name == _PrimaryKey).FirstOrDefault();
            object value = null;
            if (info != null)
            {
                value = info.GetValue(t, null);
            }
            else
            {
                return;
            }
            Data.Update<T>(t, _PrimaryKey, value);
        }

        /// <summary>
        /// 依据条件删除信息
        /// </summary>
        /// <param name="query">条件</param>
        public virtual void Delete(Expression<Func<T, bool>> query)
        {
            Data.DeleteEntitys<T>(query);
        }

        /// <summary>
        /// 依据条件获取相关信息表
        /// </summary>
        /// <param name="strWhere">Where条件</param>
        /// <returns>数据集合</returns>
        public virtual List<T> GetListByWhere(string strWhere)
        {
            StringBuilder strSql = new StringBuilder();
            strSql.AppendFormat("select {1} from {0}", _TableName, _QueryColums);
            if (!string.IsNullOrEmpty(strWhere))
            {
                strSql.AppendFormat(" where {0}", strWhere);
            }
            return Data.ExecuteQuery<T>(strSql.ToString()).ToList();
        }

        public virtual List<T> GetListByWhere()
        {
           return GetListByWhere(string.Empty);
        } 

        /// <summary>
        /// 依据条件获取相关信息
        /// </summary>
        /// <param name="strTableName">表名</param>
        /// <param name="strColums">相关列（前面可加Top）</param>
        /// <param name="strWhere">Where条件</param>
        /// <returns>数据集合</returns>
        public virtual List<T> GetListByWhere(string strTableName,string strColums,string strWhere,string strOrderBy)
        {

            StringBuilder strSql = new StringBuilder();
            strSql.AppendFormat("select  {1}  from {0}", strTableName, strColums);
            if (!string.IsNullOrEmpty(strWhere))
            {
                strSql.AppendFormat(" where {0}", strWhere);
            }

            if (!string.IsNullOrEmpty(strOrderBy))
            {
                strSql.AppendFormat(" Order by {0}", strOrderBy);
            }

            return Data.ExecuteQuery<T>(strSql.ToString()).ToList();
        }

        /// <summary>
        /// 依据条件获取相关监測信息表
        /// </summary>
        /// <param name="strWhere">Where条件</param>
        /// <returns>数据集合</returns>
        public virtual List<T> GetListByWhere(Expression<Func<T, bool>> query)
        {
            return Data.GetAllEntity<T>(query);
        }

        /// <summary>
        /// 获取列最大值
        /// </summary>
        /// <param name="CloumnName">列名</param>
        /// <returns>最大值</returns>
        public virtual object GetCloumnNameMaxValue<T2>(string CloumnName)
        {
            if (string.IsNullOrEmpty(CloumnName))
            {
                throw new Exception("列名值不能为空");
            }
            StringBuilder strSql = new StringBuilder();
            strSql.AppendFormat("select max({1}) as val from {0}", _TableName, CloumnName);
            return Data.ExecuteQuery<T2>(strSql.ToString()).FirstOrDefault();

        }

        /// <summary>
        /// 获取最大主键
        /// </summary>
        /// <returns></returns>
        protected virtual int? GetMaxPrimaryKey()
        {
            StringBuilder strSql = new StringBuilder();
            strSql.AppendFormat("select max({1}) from {0}", _TableName, _PrimaryKey);
            return Data.ExecuteQuery<int>(strSql.ToString()).FirstOrDefault();
        }
    }
}