Entity Framework底层操作封装(2)
在http://blog.csdn.net/jacky4955/article/details/9138411(http://blog.csdn.net/jacky4955/article/details/9138411)里面,是对操作底层的封装,但对于偶来说,其实并不满意。因为操作还是显得太过繁琐,每一次都得去实现基础的几个方法,即使他的代码很少,这个也是一种浪费,作为一个攻城师,坚决不做码农,不去重复同样的工作。于是针对DAL的数据操作做了一个父类。
上代码:
- using System;
- using System.Collections.Generic;
- using System.Linq;
- using System.Text;
- using System.Linq.Expressions;
- using System.Data.Objects.DataClasses;
- using System.Reflection;
- namespace NOAS.PublicOpinionMonitor.Access.Common
- {
- public class AccessBase<T> where T : class
- {
- private string _strTableName;
- private string _ColumsName;
- private string _PrimaryKey;
- private Type _PrimaryKeyType;
- public AccessBase(string PrimaryKey = "", string strTableName = "", string ColumsName = "")
- {
- Type t = typeof(T);
- if (string.IsNullOrEmpty(strTableName))
- {
- strTableName = t.Name; //GetType(t).ToString();
- }
- _strTableName = strTableName;
- if (string.IsNullOrEmpty(ColumsName))
- {
- _ColumsName = " * ";
- }
- if (string.IsNullOrEmpty(PrimaryKey))
- {
- PropertyInfo[] infos = t.GetProperties();
- _PrimaryKey = getPrimaryKey(infos);
- }
- }
- /// <summary>
- /// 获取主键,此方式只适用于edmx数据表结构
- /// </summary>
- /// <param name="infos"></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>
- /// 执行数据库操作基础类方法
- /// </summary>
- protected DataCommon Data = new DataCommon();
- /// <summary>
- /// 增加单个实体
- /// </summary>
- /// <param name="t"></param>
- public virtual void addEntity(T t)
- {
- Data.InsertEntity<T>(t);
- }
- public virtual T getSingleEntity(Expression<Func<T, bool>> query)
- {
- return Data.GetSingleEntity<T>(query);
- }
- public virtual T getSingleEntity(object PrimaryKeyId)
- {
- 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, PrimaryKeyId);
- break;
- case "bool":
- case "boolean":
- if ((bool)PrimaryKeyId)
- { strWhere.AppendFormat(" {0}=1", _PrimaryKey);}
- else
- { strWhere.AppendFormat(" {0}=0", _PrimaryKey); }
- break;
- default:
- strWhere.AppendFormat(" {0}='{1}'", _PrimaryKey, PrimaryKeyId);
- break;
- }
- return getListByWhere(strWhere.ToString()).FirstOrDefault();
- }
- /// <summary>
- /// 修改单个实体
- /// </summary>
- /// <param name="t"></param>
- public virtual void updateEntity(T t)
- {
- Data.Update<T>(t);
- }
- /// <summary>
- /// 根据条件删除信息
- /// </summary>
- /// <param name="query">条件</param>
- public virtual void deleteEntity(Expression<Func<T, bool>> query)
- {
- Data.DeleteEntitys<T>(query);
- }
- /// <summary>
- /// 根据条件获取相关监测信息表
- /// </summary>
- /// <param name="strWhere">Where条件</param>
- /// <returns>数据集合</returns>
- protected virtual List<T> getListByWhere(string strWhere)
- {
- StringBuilder strSql = new StringBuilder();
- strSql.AppendFormat("select {1} from {0}", _strTableName, _ColumsName);
- if (!string.IsNullOrEmpty(strWhere))
- {
- strSql.AppendFormat(" where {0}", strWhere);
- }
- return Data.ExecuteQuery<T>(strSql.ToString()).ToList();
- }
- /// <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}", _strTableName, _PrimaryKey);
- return Data.ExecuteQuery<int>(strSql.ToString()).FirstOrDefault();
- }
- }
- }
这样继承的子类,就自动拥有了增删改查的基础方法。
http://blog.csdn.net/jacky4955/article/details/9138549