Web开发：ORM框架之Freesql的入门和技巧使用小结
目录
零、官网链接
一、字段映射表
二、查询
1.freesql独特封装：between关键字
2.分页（每页 20 条数据，查询第 1 页）
3.Withsql（子查询，不建议）
3.简单查询、映射查询
4.参数查询、自定义查询
5.左外连接（框架+导航属性）
6.简单分表查询
三、增删改
1.SQL增删改
2.框架增删改（普通）
3.框架保存逻辑
四、demo
1.Model
2.Main
零、官网链接
https://freesql.net/guide/
一、字段映射表
访问官网
二、查询
1.freesql独特封装：between关键字查日期
var list = list.Where(a => a.Time.Between(time1, time2));2.分页（每页 20 条数据，查询第 1 页）
var list = fsql.Select<Topic>().Where(a => a.Id > 10).Count(out var total) //总记录数量.Page(1, 20).ToList();
3.Withsql（子查询，不建议）
class Topic
{[Column(IsIdentity = true)]public int Id { get; set; }public string Title { get; set; }public int Clicks { get; set; }public DateTime CreateTime { get; set; }public int CategoryId { get; set; }
}fsql.Select<Topic>().WithSql("select * from Topic where clicks > @val", new { val = 10 }).Page(1, 10).ToList()
//SELECT a.`Id`, a.`Clicks`, a.`CategoryId`, a.`Title`, a.`CreateTime`
//FROM (select * from Topic where clicks > @val) a
3.简单查询、映射查询
【技巧】打印sql、纠正映射
List<Student2022> list1 = freesql.Select<Student2022>().ToList(); //1.简单查询//var sql1 = freesql.Select<Student2022>().ToSql();//【技巧】获取查询SQLList<StuAndParent> list5 = freesql.Select<Student2022>().ToList<StuAndParent>();//2.查询后自动映射
//freesql.Select<Student2022>().ToList(x => new StuAndParent { xxx = x.id }) //【技巧】纠正映射4.参数查询、自定义查询
//等于=、批量in、模糊like查询
freesql.Ado.QuerySingle<T>("select * from t1 where id = @id", new { id = 1 });//同时支持字典查询
freesql.Ado.Query<T>("select * from t1 where name like @name", new { name = "%" + searchText + "%" });//同时支持字典查询
var ids = new int[] { 1, 2, 3 };
List<T> list = freesql.Ado.Query<T>("select * from t1 where id in @ids", new { ids = ids });//仅支持 Array 和 IList 类型List<StuAndParent> list2 = freesql.Ado.Query<StuAndParent>("SELECT * FROM Student_2022 A LEFT JOIN Parent B ON A.id=B.pid");//3.自定义SQL查询5.左外连接（框架+导航属性）
List<StuAndParent> list2 = freesql.Ado.Query<StuAndParent>("SELECT * FROM Student_2022 A LEFT JOIN Parent B ON A.id=B.pid");//3.自定义SQL查询List<StuAndParent> list3 = freesql.Select<Student2022, Parent>()//4.左外连接（框架，列出具体字段）.LeftJoin(w => w.t1.id == w.t2.pid).ToList(w => new StuAndParent{id= w.t1.id,name = w.t1.name,pid = w.t2.pid,pname = w.t2.pname});List<StuAndParent> list3_1 = freesql.Select<Student2022, Parent>()//5.左外连接（框架,映射结果）.LeftJoin(w => w.t1.id == w.t2.pid).ToList(x=>new StuAndParent());List<StuAndParent> list4 = freesql.Select<Student2022>() //6.左外连接(导航属性).LeftJoin<Parent>((student, parent) => student.id == parent.pid)//直接设置关联条件.ToList(x=>new StuAndParent());//转化为StuAndParent实体 [Table(Name = "Student_2022")]public class Student2022{[Column(IsPrimary = true)]public int id { get; set; }public string name { get; set; }public int? ParentId { get; set; } // 【导航关联字段】（数据库不需要设置外键，但数据库必须要有这个字段）[Navigate(nameof(ParentId))] // 设置导航属性，指定【导航关联字段】public Parent Parent { get; set; } // 关联的 Parent 实体}public class Parent{[Column(IsPrimary = true)]public int pid { get; set; }public string pname { get; set; }[Navigate(nameof(Student2022.ParentId))] // 设置导航属性，指定【导航关联字段】public Student2022 Student { get; set; } // 关联的 Student2022 实体}public class StuAndParent{public int id { get; set; }public string name { get; set; }public int pid { get; set; }public string pname { get; set; }}6.简单分表查询
//7.简单分表查询
var list6 = freesql.Select<Teacher>().ToList(); //假如是按月分表：[Table(Name = "log_{yyyyMM}", AsTable = "createtime=2022-1-1(1 month)")]注意：①需包含log_202201这张表 ②递增规律是一个月一次，确保他们存在。 ③确保有字段createtime。[Table(Name = "Teacher_{yyyy}", AsTable = "time=2023-1-1(1 year)")]public class Teacher{[Column(IsPrimary = true)]public int id { get; set; }public DateTime time { get; set; }}
三、增删改
1.SQL增删改（ADO.NET）
//8.sql增删改
bool b = freesql.Ado.ExecuteNonQuery(@"DELETE FROM Student_2022 WHERE id = 6")>0; 2.框架增删改（普通）
//9.框架增删改
freesql.Insert(entity).ExecuteAffrows();freesql.Update<T>(entity);
freesql.Update<T>().Set(a => a.Title, "新标题").Set(a => a.Time, DateTime.Now).Where(a => a.Id == 1)//过滤条件.ExecuteAffrows();freesql.Delete<T>(entity).ExecuteAffrows();
freesql.Delete<T>().Where(s => s.Id == 1).ExecuteAffrows();3.框架保存逻辑
【判断依据】主键存在=>改，主键不存在=>增
//10.保存实体（增加或修改）
var entity = new Student2022 { name = "晓晓", id = 6 };
bool b2 = freesql.InsertOrUpdate<Student2022>().SetSource(entity) .ExecuteAffrows()>0;四、demo
1.Model
using FreeSql.DataAnnotations;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;namespace FreesqlDemo
{public class Model{}[Table(Name = "Student_2022")]public class Student2022{[Column(IsPrimary = true)]public int id { get; set; }public string name { get; set; }public int? ParentId { get; set; } // 【导航关联字段】（数据库不需要设置外键，但数据库必须要有这个字段）[Navigate(nameof(ParentId))] // 设置导航属性，指定【导航关联字段】public Parent Parent { get; set; } // 关联的 Parent 实体}public class Parent{[Column(IsPrimary = true)]public int pid { get; set; }public string pname { get; set; }[Navigate(nameof(Student2022.ParentId))] // 设置导航属性，指定【导航关联字段】public Student2022 Student { get; set; } // 关联的 Student2022 实体}public class StuAndParent{public int id { get; set; }public string name { get; set; }public int pid { get; set; }public string pname { get; set; }}//假如是按月分表：[Table(Name = "log_{yyyyMM}", AsTable = "createtime=2022-1-1(1 month)")]注意：①需包含log_202201这张表 ②递增规律是一个月一次，确保他们存在。 ③确保有字段createtime。[Table(Name = "Teacher_{yyyy}", AsTable = "time=2023-1-1(1 year)")]public class Teacher{[Column(IsPrimary = true)]public int id { get; set; }public DateTime time { get; set; }}
}
2.Main
using FreeSql;
using System.Diagnostics;
using System.Net.WebSockets;
using System.Reflection.Metadata;
using static FreeSql.Internal.GlobalFilter;namespace FreesqlDemo
{public class Program{// 修正后的静态字段声明private static IFreeSql freesql = new FreeSqlBuilder().UseMonitorCommand(cmd => Trace.WriteLine($"Sql：{cmd.CommandText}")).UseConnectionString(DataType.SqlServer, @"server = DESKTOP-FTH2P3S; Database = Test; Trusted_Connection = SSPI;").Build();static void Main(string[] args){List<Student2022> list1 = freesql.Select<Student2022>().ToList(); //1.简单查询var sql1 = freesql.Select<Student2022>().ToSql();//【技巧】获取查询SQLList<StuAndParent> list5 = freesql.Select<Student2022>().ToList<StuAndParent>();//2.查询后自动映射//freesql.Select<Student2022>().ToList(a => new StuAndParent { xxx = a.ext }) //【技巧】纠正映射//等于=、批量in、模糊like查询//freesql.Ado.QuerySingle<T>("select * from t1 where id = @id", new { id = 1 });//同时支持字典查询//freesql.Ado.Query<T>("select * from t1 where name like @name", new { name = "%" + searchText + "%" });//同时支持字典查询//var ids = new int[] { 1, 2, 3 };//List<T> list = freesql.Ado.Query<T>("select * from t1 where id in @ids", new { ids = ids });//仅支持 Array 和 IList 类型List<StuAndParent> list2 = freesql.Ado.Query<StuAndParent>("SELECT * FROM Student_2022 A LEFT JOIN Parent B ON A.id=B.pid");//3.自定义SQL查询List<StuAndParent> list3 = freesql.Select<Student2022, Parent>()//4.左外连接（框架，列出具体字段）.LeftJoin(w => w.t1.id == w.t2.pid).ToList(w => new StuAndParent{id= w.t1.id,name = w.t1.name,pid = w.t2.pid,pname = w.t2.pname});List<StuAndParent> list3_1 = freesql.Select<Student2022, Parent>()//5.左外连接（框架）.LeftJoin(w => w.t1.id == w.t2.pid).ToList(x=>new StuAndParent());List<StuAndParent> list4 = freesql.Select<Student2022>() //6.左外连接(导航属性).LeftJoin<Parent>((student, parent) => student.id == parent.pid)//直接设置关联条件.ToList(x=>new StuAndParent());//转化为StuAndParent实体//7.简单分表查询var list6 = freesql.Select<Teacher>().ToList();//8.sql增删改bool b = freesql.Ado.ExecuteNonQuery(@"DELETE FROM Student_2022 WHERE id = 6")>0;//9.框架增删改//freesql.Insert(entity).ExecuteAffrows();//freesql.Update<T>(entity);//freesql.Update<T>()// .Set(a => a.Title, "新标题")// .Set(a => a.Time, DateTime.Now)// .Where(a => a.Id == 1)//过滤条件// .ExecuteAffrows();//freesql.Delete<T>(entity).ExecuteAffrows();//freesql.Delete<T>()// .Where(s => s.Id == 1)// .ExecuteAffrows();//10.保存实体（增加或修改）var entity = new Student2022 { name = "晓晓", id = 6 };bool b2 = freesql.InsertOrUpdate<Student2022>().SetSource(entity) .ExecuteAffrows()>0;}}
}