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IQueryableX ORM操作数据库作者 : 管理员 发布于 2023-04-25 23:43:32 浏览 582 次当前类库支持MySql,SqlServer,Oledb,SQLite,Oracle,DM等数据库
当前对象操作数据库写法和EF Core极度类似，因为现在大部分程序员都懒得去写SQL，再一个就是项目作大了或其它原因要改数据库，每次改数据库，那么写的SQL语句大部分要作调整，相当麻烦，并且写SQL时字段极容易写错，所以就出现了好多ORM框架，极大的提高了程序员的开发效率。
接下来我们讲一下 XiaoFeng.Data.IQueryableX的用法。
我们在上一节 数据库操作 中有讲过 ConnectionConfig 数据库连接配置对象，不明白的同学可以这节看。本节继续用当前配置对象。
建立数据库连接配置对象，FayElf.Web可为配置名称，也可以为连接串server=.;data=testdata;uid=da;pwd=123; 后边参数为数据库驱动。var ConnConfig = new ConnectionConfig("FayElf.Web", DbProviderType.SqlServer);使用 IQueryableX 可以有两种使用方式，下边模型默认就是数据库中的字段名称，也就是它们两个名称要一一对应。如果不一样，则可以用 XiaoFeng.Column 属性去配置数据库中表字段名称，下边分别举例说明。
通过 DataHelperX 创建一个 IQueryableX 对象 然后进行 IQueryableX 运算 去查数据库，IQueryableX和EF Core中的 IQueryable 非常类似，但运行效率比 IQueryable 快很多，并支持多数据库切换。
1.继承了 XiaoFeng.Model.Entity 实体模型的，我们暂且叫A方案，如下边模型/// <summary> /// 分类模型 /// </summary> [Table("Category","分类", "CategoryId",ModelType.Model,"FayElf.Web",0)] public class Category : Entity<Category> { #region 构造器 /// <summary> /// 无参构造器 /// </summary> public Category() { } #endregion #region 属性 /// <summary> /// 分类名称 /// </summary> [Column(Name="Names")] public string Name { get; set; } /// <summary> /// 分类说明 /// </summary> public string Description { get; set; } /// <summary> /// 分类ID /// </summary> public int CategoryId { get; set; } /// <summary> /// 父节点ID /// </summary> public int ParentId { get; set; } /// <summary> /// 添加日期 /// </summary> public DateTime AddDate { get; set; } #endregion #region 方法 #endregion }2.没有继续XiaoFeng.Model.Entity实体模型的，我们暂且叫B方案，如下模型
/// <summary> /// 用户模型 /// </summary> public class UserModel { #region 构造器 /// <summary> /// 无参构造器 /// </summary> public UserModel() { } #endregion #region 属性 /// <summary> /// Id /// </summary> public long Id { get; set; } /// <summary> /// 帐号 /// </summary> public string Account { get; set; } /// <summary> /// 密码 /// </summary> public string Password { get; set; } /// <summary> /// 性别 /// </summary> public int Sex { get; set; } /// <summary> /// 出生日期 /// </summary> public DateTime BirthDay { get; set; } /// <summary> /// 添加日期 /// </summary> public DateTime AddDate { get; set; } #endregion #region 方法 #endregion }首先我们先举实例讲解一下 A方案 的使用方法
//首选实例化一个 Category 实例 var category = Category.Create; //查询 var category1 = category.Find(a => a.CategoryId == 2); var category2 = category.Where(a => a.CategoryId == 2).ToEntity(); //上边两种方式是一样的 都是提取 CategoryId 等于 2 的一条数据 //列表 var category3 = category.Where(a => a.CategoryId == 3).ToList(); var category4 = category.ToList(a => a.CategoryId == 3); //上边两种方式是一样的 都是提取 CategoryId 等于 3 的列表数据 //删除 //当前语句是删除 CateogryId 等于 4 的这条记录 var delete5 = category.Where(a => a.CategoryId == 4).Delete(); //当前语句是删除查从库中查出来的一条数据给删除掉 var delete6 = category1.Delete(); //插入 new Category { Name="a", ParentId=0 }.Insert(); //更新 //当前语句是更新字段 为 Name ParentId 的字段值 条件是 CategoryId 等于 5 的记录 var update5 = category.Where(a => a.CategoryId == 5).Update(a => a.Name == "aaa" && a.ParentId == 10); //当前语句是更新 字段 Name ParentId的值 数据是上边查询出来的一条记录 category1.Name = "bbbb"; category1.ParentId = 3; var update6 = category.Update(); //联表 下边用法就是 通过 左关联 两张表 on 条件是 第一张表的 ParentId 与第二张表的 CategoryId 相同 然后字段显示为 Name,CategoryId,ParentName 的列表 var join1 = category.QueryableX.Join<Category, object[]>((a, b) => new object[] { JoinType.Left, a.ParentId == b.CategoryId }).Select((a, b) => new { a.Name, a.CategoryId, ParentName = b.Name }).ToList(); //更多表关联 有两种方法 第一种是 两张表关联的结果和第三张表关联，再关联的结果与第四经表关联 依次类推 //第二种方法就是 假设一共有5张表关联那么直接实例化 DataHelperX时直接关联5张表，建议用第一种方法。接着我们讲 B 方案用法
//创建一个带数据库的 IQueryableX 对象，下边所有的操作都是基于当前对象来操作。 var data = new DataHelperX<UserModel>(Conn); //查询 下边三种写法 运行后 结果是一样的 var userModel1 = data.Where(a => a.Account == "jacky" && a.Password == "admin123").ToEntity(); var userModel2 = data.Where(a => a.Account == "jacky").Where(a => a.Password == "admin123").ToEntity(); var userModel3 = data.First(a => a.Account == "jacky" && a.Password == "admin123"); //列表 var userList1 = data.Where(a => a.Sex == 1 || a.Account == "jacky").ToList(); //关联查询 var userList2 = data.Where(a => a.Sex == 1).Join<UserModel, object[]>((a, b) => new object[] { a.Account == b.Password }).Select((a, b) => new { a.Account, a.Password, ParentName = b.Account }).ToList(); //插入 var userModel4 = new UserModel { Account = "jacky", Password = "admin" }; var insert1 = data.Insert(userModel4); //如果想返回自增长ID则后边输入接收参数即可如下 var insert2 = data.Insert(userModel4, out var ID); //批量插入 var insert3 = data.Inserts(new List<UserModel> { userModel4,userModel4 }); //更新 var update1 = data.Where(a => a.Id == 1).Update(a => a.Password == "adminadmin"); //删除 var delete1 = data.Where(a => a.Id == 1).Delete();下边我们说一下 内部函数用法，函数扩展了基本上SQL中用到的函数，以及C#语言中的字符串处理函数的大部分，内部函数扩展方法如下：
/// <summary> /// 扩展SQL语法 /// Version : 2.0.0 /// Author : jacky /// Email : jacky@zhuovi.com /// QQ : 7092734 /// Site : www.zhuovi.com /// Create Time : 2017/12/20 9:40:00 /// Update Time : 2018/01/19 13:40:00 /// </summary> public static partial class PrototypeHelper { #region 扩展SQL 语法 #region 扩展SQL 字段加值+ /// <summary> /// 字段加值 /// </summary> /// <typeparam name="T">类型</typeparam> /// <param name="obj">对象</param> /// <param name="value">值</param> /// <returns></returns> public static T AddSQL<T>(this T obj, T value) { return obj; } #endregion #region 扩展SQL 字段减值- /// <summary> /// 字段减值 /// </summary> /// <typeparam name="T">类型</typeparam> /// <param name="obj">对象</param> /// <param name="value">值</param> /// <returns></returns> public static T SubtractSQL<T>(this T obj, T value) { return obj; } #endregion #region 扩展SQL 字段乘值* /// <summary> /// 字段乘值 /// </summary> /// <typeparam name="T">类型</typeparam> /// <param name="obj">对象</param> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static T MultiplySQL<T>(this T obj, T value) { return obj; } #endregion #region 扩展SQL 字段除值/ /// <summary> /// 字段除值 /// </summary> /// <typeparam name="T">类型</typeparam> /// <param name="obj">对象</param> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static T DivideSQL<T>(this T obj, T value) { return obj; } #endregion #region 扩展SQL Between /// <summary> /// 扩展SQL Between /// </summary> /// <param name="obj">对象</param> /// <param name="startValue">开始值</param> /// <param name="endValue">结束值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static Boolean BetweenSQL(this object obj, object startValue, object endValue) { return true; } #endregion #region 扩展SQL ISNULL /// <summary> /// 扩展SQL ISNULL /// </summary> /// <typeparam name="T">类型</typeparam> /// <param name="obj">对象</param> /// <param name="defaultValue">默认值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static T IsNullSQL<T>(this T obj, T defaultValue) { return defaultValue; } #endregion #region 扩展SQL in 语法 /// <summary> /// 扩展SQL in语法 /// </summary> /// <typeparam name="T">类型</typeparam> /// <param name="obj">对象</param> /// <param name="array">数组织</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static bool InSQL<T>(this T obj, IEnumerable<T> array) { return true; } /// <summary> /// 扩展SQL in语法 /// </summary> /// <typeparam name="T">类型</typeparam> /// <param name="obj">对象</param> /// <param name="array">数组织</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static bool InSQL<T>(this T obj, T[] array) { return true; } /// <summary> /// 扩展SQL in语法 /// </summary> /// <typeparam name="T">类型</typeparam> /// <typeparam name="T1">类型</typeparam> /// <param name="obj">对象</param> /// <param name="queryableX">IQueryableX对象</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static Boolean InSQL<T, T1>(this T obj, IQueryableX<T1> queryableX) { return true; } /// <summary> /// 扩展SQL in语法 /// </summary> /// <typeparam name="T">类型</typeparam> /// <param name="obj">对象</param> /// <param name="array">数组</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static bool InSQL<T>(this T obj, object[] array) { return true; } /// <summary> /// 扩展SQL not in语法 /// </summary> /// <typeparam name="T">类型</typeparam> /// <param name="obj">对象</param> /// <param name="array">数组</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static bool NotInSQL<T>(this T obj, IEnumerable<T> array) { return true; } /// <summary> /// 扩展SQL not in语法 /// </summary> /// <typeparam name="T">类型</typeparam> /// <param name="obj">对象</param> /// <param name="array">数组</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static bool NotInSQL<T>(this T obj, T[] array) { return true; } /// <summary> /// 扩展SQL not in语法 /// </summary> /// <typeparam name="T">类型</typeparam> /// <typeparam name="T1">类型</typeparam> /// <param name="obj">对象</param> /// <param name="queryableX">IQueryableX对象</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static Boolean NotInSQL<T, T1>(this T obj, IQueryableX<T1> queryableX) { return true; } /// <summary> /// 扩展SQL not in语法 /// </summary> /// <typeparam name="T">类型</typeparam> /// <param name="obj">对象</param> /// <param name="array">数组</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static bool NotInSQL<T>(this T obj, object[] array) { return true; } #endregion #region 扩展SQL like 语法 /// <summary> /// 扩展SQL like 语法 /// </summary> /// <param name="str">字符串</param> /// <param name="likeStr">子串</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static bool LikeSQL(this object str, string likeStr) { return true; } /// <summary> /// 扩展SQL not like 语法 /// </summary> /// <param name="str">字符串</param> /// <param name="likeStr">子串</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static bool NotLikeSQL(this string str, string likeStr) { return true; } /// <summary> /// 扩展SQL like 语法 /// </summary> /// <param name="str">字符串</param> /// <param name="likeStr">子串</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static bool LikeSQLX(this object str, string likeStr) { return true; } /// <summary> /// 扩展SQL not like 语法 /// </summary> /// <param name="str">字符串</param> /// <param name="likeStr">子串</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static bool NotLikeSQLX(this string str, string likeStr) { return true; } #endregion #region 扩展SQL DateAdd 语法 /// <summary> /// 扩展SQL DateAdd 语法 /// </summary> /// <param name="date">日期</param> /// <param name="val">值</param> /// <param name="format">格式 年yy,yyyy 季度qq,q 月mm,m 年中的日dy,y 日dd,d 周wk,ww 星期dw,w 小时hh 分钟mi,n 秒ss,s 毫秒ms 微秒mcs 纳秒ns</param> /// <returns></returns> public static DateTime DateAddSQL(this DateTime date, long val, string format) { return date; } /// <summary> /// 扩展SQL DateAdd 语法 /// </summary> /// <param name="date">日期</param> /// <param name="val">值</param> /// <param name="format">格式 年yy,yyyy 季度qq,q 月mm,m 年中的日dy,y 日dd,d 周wk,ww 星期dw,w 小时hh 分钟mi,n 秒ss,s 毫秒ms 微秒mcs 纳秒ns</param> /// <returns></returns> public static DateTime DateAddSQL(this DateTime? date, long val, string format) { return date.GetValueOrDefault(); } #endregion #region 扩展SQL DateDiff 语法 /// <summary> /// 扩展SQL DateDiff 语法 /// </summary> /// <param name="firstDate">第一个时间</param> /// <param name="SecondDate">第二个时间</param> /// <param name="format">格式 年yy,yyyy 季度qq,q 月mm,m 年中的日dy,y 日dd,d 周wk,ww 星期dw,w 小时hh 分钟mi,n 秒ss,s 毫秒ms 微秒mcs 纳秒ns</param> /// <returns></returns> public static int DateDiffSQL(this DateTime? firstDate, DateTime? SecondDate, string format) { return 1; } /// <summary> /// 扩展SQL DateDiff 语法 /// </summary> /// <param name="firstDate">第一个时间</param> /// <param name="SecondDate">第二个时间</param> /// <param name="format">格式 年yy,yyyy 季度qq,q 月mm,m 年中的日dy,y 日dd,d 周wk,ww 星期dw,w 小时hh 分钟mi,n 秒ss,s 毫秒ms 微秒mcs 纳秒ns</param> /// <returns></returns> public static int DateDiffSQL(this DateTime firstDate, DateTime SecondDate, string format) { return 1; } #endregion #region 扩展SQL DatePart 语法 /// <summary> /// 扩展SQL DatePart 语法 /// </summary> /// <param name="Date">当前时间</param> /// <param name="format">格式 年yy,yyyy 季度qq,q 月mm,m 年中的日dy,y 日dd,d 周wk,ww 星期dw,w 小时hh 分钟mi,n 秒ss,s 毫秒ms 微秒mcs 纳秒ns</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static int DatePartSQL(this DateTime? Date, string format) { return 0; } /// <summary> /// 扩展SQL DatePart 语法 /// </summary> /// <param name="Date">当前时间</param> /// <param name="format">格式 年yy,yyyy 季度qq,q 月mm,m 年中的日dy,y 日dd,d 周wk,ww 星期dw,w 小时hh 分钟mi,n 秒ss,s 毫秒ms 微秒mcs 纳秒ns</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static int DatePartSQL(this DateTime Date, string format) { return 0; } #endregion #region 扩展SQL DateFormat 语法 /// <summary> /// 扩展SQL DateFormat 语法 /// </summary> /// <param name="Date">当前时间</param> /// <param name="format"></param> /// <returns></returns> public static string DateFormatSQL(this DateTime? Date, string format) { return string.Empty; } /// <summary> /// 扩展SQL DateFormat 语法 /// </summary> /// <param name="Date">当前时间</param> /// <param name="format"></param> /// <returns></returns> public static string DateFormatSQL(this DateTime Date, string format) { return string.Empty; } #endregion #region 扩展SQL Charindex 语法 /// <summary> /// 扩展SQL Charindex 语法 /// </summary> /// <param name="str">字符串</param> /// <param name="IndexStr">子串</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static int CharIndexSQL(this string str, string IndexStr) { return 1; } #endregion #region 扩展SQL Patindex语法 /// <summary> /// 扩展SQL Patindex语法 /// </summary> /// <param name="str">字符串</param> /// <param name="IndexStr">子串</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static int PatindexSQL(this string str, string IndexStr) { return 1; } #endregion #region 扩展SQL Abs 算法 /// <summary> /// 扩展SQL Abs 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static int AbsSQL(this int value) { return 1; } /// <summary> /// 扩展SQL Abs 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static int AbsSQL(this int? value) { return 1; } /// <summary> /// 扩展SQL Abs 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static Int16 AbsSQL(this Int16? value) { return 1; } /// <summary> /// 扩展SQL Abs 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static Int16 AbsSQL(this Int16 value) { return 1; } /// <summary> /// 扩展SQL Abs 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static Int64 AbsSQL(this Int64? value) { return 1; } /// <summary> /// 扩展SQL Abs 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static Int64 AbsSQL(this Int64 value) { return 1; } /// <summary> /// 扩展SQL Abs 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static Double AbsSQL(this Double? value) { return 1; } /// <summary> /// 扩展SQL Abs 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static Double AbsSQL(this Double value) { return 1; } /// <summary> /// 扩展SQL Abs 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static decimal AbsSQL(this decimal? value) { return 1; } /// <summary> /// 扩展SQL Abs 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static decimal AbsSQL(this decimal value) { return 1; } /// <summary> /// 扩展SQL Abs 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static float AbsSQL(this float? value) { return 1; } /// <summary> /// 扩展SQL Abs 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static float AbsSQL(this float value) { return 1; } #endregion #region 扩展SQL Floor 算法 /// <summary> /// 扩展SQL Floor 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static Double FloorSQL(this Double? value) { return 1; } /// <summary> /// 扩展SQL Abs 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static Double FloorSQL(this Double value) { return 1; } /// <summary> /// 扩展SQL Floor 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static decimal FloorSQL(this decimal? value) { return 1; } /// <summary> /// 扩展SQL Floor 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static decimal FloorSQL(this decimal value) { return 1; } /// <summary> /// 扩展SQL Floor 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static float FloorSQL(this float? value) { return 1; } /// <summary> /// 扩展SQL Floor 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static float FloorSQL(this float value) { return 1; } #endregion #region 扩展SQL Ceiling 算法 /// <summary> /// 扩展SQL Ceiling 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static Double CeilingSQL(this Double? value) { return 1; } /// <summary> /// 扩展SQL Ceiling 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static Double CeilingSQL(this Double value) { return 1; } /// <summary> /// 扩展SQL Ceiling 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static decimal CeilingSQL(this decimal? value) { return 1; } /// <summary> /// 扩展SQL Ceiling 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static decimal CeilingSQL(this decimal value) { return 1; } /// <summary> /// 扩展SQL Ceiling 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static float CeilingSQL(this float? value) { return 1; } /// <summary> /// 扩展SQL Ceiling 算法 /// </summary> /// <param name="value">值</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static float CeilingSQL(this float value) { return 1; } #endregion #region 扩展SQL Round 算法 /// <summary> /// 扩展SQL Round 算法 /// </summary> /// <param name="value">值</param> /// <param name="len">小数点保留长度</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static Double RoundSQL(this Double? value, int len) { return 1; } /// <summary> /// 扩展SQL Round 算法 /// </summary> /// <param name="value">值</param> /// <param name="len">小数点保留长度</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static Double RoundSQL(this Double value, int len) { return 1; } /// <summary> /// 扩展SQL Round 算法 /// </summary> /// <param name="value">值</param> /// <param name="len">小数点保留长度</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static decimal RoundSQL(this decimal? value, int len) { return 1; } /// <summary> /// 扩展SQL Round 算法 /// </summary> /// <param name="value">值</param> /// <param name="len">小数点保留长度</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static decimal RoundSQL(this decimal value, int len) { return 1; } /// <summary> /// 扩展SQL Abs 算法 /// </summary> /// <param name="value">值</param> /// <param name="len">小数点保留长度</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static float RoundSQL(this float? value, int len) { return 1; } /// <summary> /// 扩展SQL Round 算法 /// </summary> /// <param name="value">值</param> /// <param name="len">小数点保留长度</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static float RoundSQL(this float value, int len) { return 1; } #endregion #region 扩展SQL Left /// <summary> /// 扩展SQL Left /// </summary> /// <param name="str">字符串</param> /// <param name="num">第几位</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static string LeftSQL(this string str, int num) { return ""; } #endregion #region 扩展SQL Right /// <summary> /// 扩展SQL Right /// </summary> /// <param name="str">字符串</param> /// <param name="num">第几位</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static string RightSQL(this string str, int num) { return ""; } #endregion #region 扩展SQL Len /// <summary> /// 扩展SQL Len /// </summary> /// <param name="str">字符串</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static int LengthSQL(this string str) { return 1; } #endregion #region 扩展SQL Replace /// <summary> /// 扩展SQL Replace /// </summary> /// <param name="str">字符串</param> /// <param name="oldString">原字符串</param> /// <param name="replaceString">新字符串</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static string ReplaceSQL(this string str, string oldString, string replaceString) { return ""; } #endregion #region 扩展SQL Replicate /// <summary> /// 扩展SQL Replicate /// </summary> /// <param name="str">字符串</param> /// <param name="num">重复次数</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static string ReplicateSQL(this string str, int num) { return ""; } #endregion #region 扩展SQL Reverse /// <summary> /// 扩展SQL Reverse /// </summary> /// <param name="str">字符串</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static string ReverseSQL(this string str) { return ""; } #endregion #region 扩展SQL Stuff /// <summary> /// 扩展SQL Stuff /// </summary> /// <param name="str">字符串</param> /// <param name="strat">开始位置</param> /// <param name="length">长度</param> /// <param name="replaceString">替换字符串</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static string StuffSQL(this string str, int strat, int length, string replaceString) { return ""; } #endregion #region 扩展SQL Substring /// <summary> /// 扩展SQL Substring /// </summary> /// <param name="str">字符串</param> /// <param name="start">开始位置</param> /// <param name="length">长度</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static string SubstringSQL(this string str, int start, int length) { return ""; } #endregion #region 扩展SQL Trim /// <summary> /// 扩展SQL Ltrim /// </summary> /// <param name="str">字符串</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static string LTrimSQL(this string str) { return ""; } /// <summary> /// 扩展SQL Rtrim /// </summary> /// <param name="str">字符串</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static string RTrimSQL(this string str) { return ""; } /// <summary> /// 扩展SQL Trim /// </summary> /// <param name="str">字符串</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static string TrimSQL(this string str) { return ""; } #endregion #region 扩展SQL Lower /// <summary> /// 扩展SQL Lower /// </summary> /// <param name="str">字符串</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static string LowerSQL(this string str) { return ""; } #endregion #region 扩展SQL Upper /// <summary> /// 扩展SQL Upper /// </summary> /// <param name="str">字符串</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static string UpperSQL(this string str) { return ""; } #endregion #region 扩展SQL Count /// <summary> /// 扩展SQL Count /// </summary> /// <param name="str">字符串</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static int CountSQL(this object str) { return 0; } #endregion #region 扩展SQL MAX /// <summary> /// 扩展SQL MAX /// </summary> /// <typeparam name="T">类型</typeparam> /// <param name="obj">字符串</param> /// <returns></returns> public static T MaxSQL<T>(this T obj) { return obj; } #endregion #region 扩展SQL MIN /// <summary> /// 扩展SQL MIN /// </summary> /// <typeparam name="T">类型</typeparam> /// <param name="obj">字符串</param> /// <returns></returns> public static T MinSQL<T>(this T obj) { return obj; } #endregion #region 扩展SQL SUM /// <summary> /// 扩展SQL SUM /// </summary> /// <typeparam name="T">类型</typeparam> /// <param name="obj">字符串</param> /// <returns></returns> public static T SumSQL<T>(this T obj) { return obj; } #endregion #region 扩展SQL AVG /// <summary> /// 扩展SQL AVG /// </summary> /// <typeparam name="T">类型</typeparam> /// <param name="obj">字符串</param> /// <returns></returns> public static T AvgSQL<T>(this T obj) { return obj; } #endregion #region 设置字段别名 /// <summary> /// 设置字段别名 /// </summary> /// <typeparam name="T">类型</typeparam> /// <param name="obj">对象</param> /// <param name="ColumnName">别名</param> /// <returns></returns> [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0060:删除未使用的参数", Justification = "<挂起>")] public static T As<T>(this T obj, string ColumnName) { return obj; } #endregion #region 转换类型 /// <summary> /// 转换类型 /// </summary> /// <typeparam name="T">类型</typeparam> /// <param name="obj">对象</param> /// <param name="dataType">目标类型</param> /// <returns></returns> public static T CastSQL<T>(this T obj,string dataType) { return obj; } #endregion #region SQL参数化调整 /// <summary> /// SQL参数化调整 /// </summary> /// <param name="_">SQL语句</param> /// <param name="dbProvider">数据库驱动</param> /// <returns></returns> public static string SQLFormat(this string _, DbProviderType dbProvider) { switch (dbProvider) { case DbProviderType.Dameng: return _.ReplacePattern(@"@((Sub_(\d+_)?)?ParamName\d+)", "?"); case DbProviderType.Oracle: return _.ReplacePattern(@"@((Sub_(\d+_)?)?ParamName\d+)", ":$1"); } return _; } #endregion #endregion }下边举例演示
//内部方法 //查询出分类名称前边包含 字符串 a 的数据 var category5 = category.Where(a => a.Name.StartsWith("a")).ToList(); //查询出分类名第2位开始4个长度的字符是abcd的数据 var category6 = category.Where(a => a.Name.Substring(2, 4) == "abcd").ToList(); //查询 出分类表中添加时间比现在时间少3个时小的 数据 var category7 = category.Where(a => a.AddDate.DateDiffSQL(DateTime.Now, "hh") == 3).ToList();到这里 IQueryableX 基本使用基本上讲完了，以后还有扩展的 IQueryableQ 它是操作SQL体用的 比如 下边的SQL
if(exists(select top 1 from TestTb where ID = 1)) delete from testTb where ID = 1;以后会用一节 专一讲 IQueryableQ的使用方法。
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