/// <summary> /// Sql查询 /// </summary> private void SqlQuery() { using (var db = SugarDao.GetInstance()) { //转成list List <Student> list1 = db.SqlQuery <Student>("select * from Student"); //转成list带参 List <Student> list2 = db.SqlQuery <Student>("select * from Student where id=@id", new { id = 1 }); //转成dynamic dynamic list3 = db.SqlQueryDynamic("select * from student"); //转成json string list4 = db.SqlQueryJson("select * from student"); //返回int var list5 = db.SqlQuery <int>("select top 1 id from Student").SingleOrDefault(); //反回键值 Dictionary <string, string> list6 = db.SqlQuery <KeyValuePair <string, string> >("select id,name from Student").ToDictionary(it => it.Key, it => it.Value); //反回List<string[]> var list7 = db.SqlQuery <string[]>("select top 1 id,name from Student").SingleOrDefault(); //存储过程 var spResult = db.SqlQuery <School>("exec sp_school @p1,@p2", new { p1 = 1, p2 = 2 }); //获取第一行第一列的值 string v1 = db.GetString("select '张三' as name"); int v2 = db.GetInt("select 1 as name"); double v3 = db.GetDouble("select 1 as name"); decimal v4 = db.GetDecimal("select 1 as name"); } }
public void Init() { using (SqlSugarClient db = SugarDao.GetInstance())//开启数据库连接 { Student s = new Student() { name = "张" + new Random().Next(1, int.MaxValue) }; db.Insert(s); //插入一条记录 (有主键也好,没主键也好,有自增列也好都可以插进去) List <Student> list = new List <Student>() { new Student() { name = "张" + new Random().Next(1, int.MaxValue) }, new Student() { name = "张" + new Random().Next(1, int.MaxValue) } }; db.InsertRange(list); //批量插入 } }
/// <summary> /// 新容器转换 /// </summary> private void NewSelect() { using (SqlSugarClient db = SugarDao.GetInstance()) { var list2 = db.Queryable <Student>().Where(c => c.id < 10).Select(c => new classNew { newid = c.id, newname = c.name, xx_name = c.name }).ToList(); //不支持匿名类转换,也不建议使用 var list3 = db.Queryable <Student>().Where(c => c.id < 10).Select(c => new { newid = c.id, newname = c.name, xx_name = c.name }).ToDynamic(); //匿名类转换 } }
public void Init() { using (SqlSugarClient db = SugarDao.GetInstance())//开启数据库连接 { var r1 = db.GetDataTable("select * from student"); var r2 = db.GetSingle <Student>("select top 1 * from student"); var r3 = db.GetScalar("select count(1) from student"); var r4 = db.GetReader("select count(1) from student"); r4.Dispose(); var r5 = db.GetString("select top 1 name from student"); var r6 = db.ExecuteCommand("select 1"); } }
public void Init() { using (SqlSugarClient db = SugarDao.GetInstance())//开启数据库连接 { Student s = new Student() { name = "张" + new Random().Next(1, int.MaxValue) }; db.Insert(s); //插入一条记录 (有主键也好,没主键也好,有自增列也好都可以插进去) List <Student> list = new List <Student>() { new Student() { name = "张" + new Random().Next(1, int.MaxValue) }, new Student() { name = "张" + new Random().Next(1, int.MaxValue) } }; db.InsertRange(list); //批量插入 //高性能批量插入 //注意:性能比InsertRange高,功能没有InsertRange全,不支持别名表和排除列 using (SqlSugarClient db2 = SugarDao.GetInstance())//开启数据库连接 { var list2 = new List <Student>() { new Student() { isOk = true, name = "张三", sch_id = 1, sex = "男" }, new Student() { isOk = true, name = "sun", sch_id = 1, sex = "女" }, new Student() { isOk = true, name = "mama", sch_id = 1, sex = "gril" } }; db.SqlBulkCopy <Student>(list2); } } }
/// <summary> /// 新容器转换 /// </summary> private void NewSelect() { using (SqlSugarClient db = SugarDao.GetInstance()) { var list2 = db.Queryable <Student>().Where(c => c.id < 10).Select(c => new classNew { newid = c.id, newname = c.name, xx_name = c.name }).ToList(); //不支持匿名类转换,也不建议使用 var list3 = db.Queryable <Student>().Where(c => c.id < 10).Select(c => new { newid = c.id, newname = c.name, xx_name = c.name }).ToDynamic(); //匿名类转换 var list4 = db.Queryable <Student>().Where(c => c.id < 10).Select("id as newid, name as newname ,name as xx_name").ToDynamic(); //匿名类转换 var jList1 = db.Queryable <Student>() .JoinTable <Student, School>((s1, s2) => s1.sch_id == s2.id) // left join School s2 on s1.id=s2.id .Where <Student, School>((s1, s2) => s1.id > 1) // where s1.id>1 .OrderBy <Student, School>((s1, s2) => s1.id) //order by s1.id 多个order可以 .oderBy().orderby 叠加 .Skip(1) .Take(2) .Select <Student, School, classNew>((s1, s2) => new classNew() { newid = s1.id, newname = s2.name, xx_name = s1.name }) //select目前只支持这种写法 .ToList(); var jList2 = db.Queryable <Student>() .JoinTable <Student, School>((s1, s2) => s1.sch_id == s2.id) // left join School s2 on s1.id=s2.id .Where <Student, School>((s1, s2) => s1.id > 1) // where s1.id>1 .OrderBy <Student, School>((s1, s2) => s1.id) //order by s1.id 多个order可以 .oderBy().orderby 叠加 .Skip(1) .Take(2) .Select <Student, School, classNew>((s1, s2) => new classNew() { newid = s1.id, newname = s1.name, xx_name = s1.name }) //select目前只支持这种写法 .ToDynamic(); var jList3 = db.Queryable <Student>() .JoinTable <Student, School>((s1, s2) => s1.sch_id == s2.id) // left join School s2 on s1.id=s2.id .Where <Student, School>((s1, s2) => s1.id > 1) // where s1.id>1 .OrderBy <Student, School>((s1, s2) => s1.id) //order by s1.id 多个order可以 .oderBy().orderby 叠加 .Skip(1) .Take(2) .Select <Student, classNew>(s1 => new classNew() { newid = s1.id, newname = s1.name, xx_name = s1.name }) //select目前只支持这种写法 .ToDynamic(); } }
public void Init() { using (var db = SugarDao.GetInstance()) { //真删除 db.Delete <School, int>(10);//注意主键必需为实体类的第一个属性 db.Delete <School>(it => it.id > 100); db.Delete <School, string>(new string[] { "100", "101", "102" }); //假删除 //db.FalseDelete<school>("is_del", 100); //等同于 update school set is_del=0 where id in(100) //db.FalseDelete<school>("is_del", it=>it.id==100); } }
public void Init() { using (SqlSugarClient db = SugarDao.GetInstance()) { var stuList = db.Queryable <Student>().ToList(); db.Insert <Student>(new Student() { sch_id = SchoolEnum.蓝翔2 }); db.Update <Student>(new Student() { sch_id = SchoolEnum.蓝翔1, id = 1 }); var stuList2 = db.Queryable <Student>().Where(it => it.sch_id == SchoolEnum.蓝翔1).ToList(); } }
public void Init() { using (var db = SugarDao.GetInstance()) { //根据当前数据库生成所有表的实体类文件 (参数:SqlSugarClient ,文件目录,命名空间) db.ClassGenerating.CreateClassFiles(db, @"D:\SqlSugarModelFiles2", "Models"); //根据表名生成实体类文件 //db.ClassGenerating.CreateClassFilesByTableNames(db, Server.MapPath("~/Models"), "Models" , "student","school"); //根据表名生成class字符串 var str = db.ClassGenerating.TableNameToClass(db, "Student"); //根据SQL语句生成class字符串 var str2 = db.ClassGenerating.SqlToClass(db, "select top 1 * from Student", "student"); } }
public void Init() { using (SqlSugarClient db = SugarDao.GetInstance()) //开启数据库连接 { db.IsNoLock = true; //启用无锁查询 db.CommandTimeOut = 30000; //设置超时时间 try { db.BeginTran();//开启事务 //db.BeginTran(IsolationLevel.ReadCommitted);+3重载可以设置事世隔离级别 db.CommitTran();//提交事务 } catch (Exception) { db.RollbackTran();//回滚事务 throw; } } }
public void Init() { int id = 10; using (var db = SugarDao.GetInstance()) { //指定列更新 db.Update <School>(new { name = "蓝翔2" }, it => it.id == id); db.Update <School, int>(new { name = "蓝翔2" }, 10, 13, 12); db.Update <School, string>(new { name = "蓝翔2" }, new string[] { "11", "12" }); //整个实体更新 db.Update(new School { id = id, name = "蓝翔2" }); db.Update <School>(new School { id = id, name = "蓝翔2" }, it => it.id == id); //设置不更新列 db.DisableUpdateColumns = new string[] { "CreateTime" };//设置CreateTime不更新 TestUpdateColumns updObj = new TestUpdateColumns() { VGUID = Guid.Parse("542b5a27-6984-47c7-a8ee-359e483c8470"), Name = "xx", Name2 = "xx2", IdentityField = 0, CreateTime = null }; //CreateTime将不会被更新 db.Update(updObj); //以前实现这种更新需要用指定列的方式实现,现在就简单多了。 } }
/// <summary> /// 单表查询 /// </summary> private void QueryableDemo() { using (var db = SugarDao.GetInstance()) { //---------Queryable<T>,扩展函数查询---------// //针对单表或者视图查询 //查询所有 var student = db.Queryable <Student>().ToList(); var studentDynamic = db.Queryable <Student>().ToDynamic(); var studentJson = db.Queryable <Student>().ToJson(); //查询单条 var single = db.Queryable <Student>().Single(c => c.id == 1); //查询单条没有记录返回空对象 var single2 = db.Queryable <Student>().Where(c => c.id == 1).SingleOrDefault(); //查询第一条 var first = db.Queryable <Student>().Where(c => c.id == 1).First(); var first2 = db.Queryable <Student>().Where(c => c.id == 1).FirstOrDefault(); //取10-20条 var page1 = db.Queryable <Student>().Where(c => c.id > 10).OrderBy(it => it.id).Skip(10).Take(20).ToList(); //上一句的简化写法,同样取10-20条 var page2 = db.Queryable <Student>().Where(c => c.id > 10).OrderBy(it => it.id).ToPageList(2, 10); //查询条数 var count = db.Queryable <Student>().Where(c => c.id > 10).Count(); //从第2条开始以后取所有 var skip = db.Queryable <Student>().Where(c => c.id > 10).OrderBy(it => it.id).Skip(2).ToList(); //取前2条 var take = db.Queryable <Student>().Where(c => c.id > 10).OrderBy(it => it.id).Take(2).ToList(); // Not like string conval = "a"; var notLike = db.Queryable <Student>().Where(c => !c.name.Contains(conval.ToString())).ToList(); //Like conval = "三"; var like = db.Queryable <Student>().Where(c => c.name.Contains(conval)).ToList(); // 可以在拉姆达使用 ToString和 Convert,比EF出色的地方 var convert1 = db.Queryable <Student>().Where(c => c.name == "a".ToString()).ToList(); var convert2 = db.Queryable <Student>().Where(c => c.id == Convert.ToInt32("1")).ToList();// var convert3 = db.Queryable <Student>().Where(c => DateTime.Now > Convert.ToDateTime("2015-1-1")).ToList(); var convert4 = db.Queryable <Student>().Where(c => DateTime.Now > DateTime.Now).ToList(); //支持字符串Where 让你解决,更复杂的查询 var student12 = db.Queryable <Student>().Where(c => "a" == "a").Where("id>100").ToList(); var student13 = db.Queryable <Student>().Where(c => "a" == "a").Where("id>100 and id in( select 1)").ToList(); //存在记录反回true,则否返回false bool isAny100 = db.Queryable <Student>().Any(c => c.id == 100); bool isAny1 = db.Queryable <Student>().Any(c => c.id == 1); //获取最大Id object maxId = db.Queryable <Student>().Max(it => it.id); int maxId1 = db.Queryable <Student>().Max(it => it.id).ObjToInt(); //拉姆达 int maxId2 = db.Queryable <Student>().Max <Student, int>("id"); //字符串写法 //获取最小 int minId1 = db.Queryable <Student>().Where(c => c.id > 0).Min(it => it.id).ObjToInt(); //拉姆达 int minId2 = db.Queryable <Student>().Where(c => c.id > 0).Min <Student, int>("id"); //字符串写法 //order By var orderList = db.Queryable <Student>().OrderBy("id desc,name asc").ToList(); //字符串支持多个排序 //可以多个order by表达示 var order2List = db.Queryable <Student>().OrderBy(it => it.name).OrderBy(it => it.id, OrderByType.desc).ToList(); // order by name as ,order by id desc //In var intArray = new[] { "5", "2", "3" }; var intList = intArray.ToList(); var list0 = db.Queryable <Student>().In(it => it.id, 1, 2, 3).ToList(); var list1 = db.Queryable <Student>().In(it => it.id, intArray).ToList(); var list2 = db.Queryable <Student>().In("id", intArray).ToList(); var list3 = db.Queryable <Student>().In(it => it.id, intList).ToList(); var list4 = db.Queryable <Student>().In("id", intList).ToList(); //分组查询 var list7 = db.Queryable <Student>().Where(c => c.id < 20).GroupBy(it => it.sex).Select("sex,Count=count(*)").ToDynamic(); var list8 = db.Queryable <Student>().Where(c => c.id < 20).GroupBy(it => it.sex).GroupBy(it => it.id).Select("id,sex,Count=count(*)").ToDynamic(); List <SexTotal> list9 = db.Queryable <Student>().Where(c => c.id < 20).GroupBy(it => it.sex).Select <Student, SexTotal>("Sex,Count=count(*)").ToList(); List <SexTotal> list10 = db.Queryable <Student>().Where(c => c.id < 20).GroupBy("sex").Select <Student, SexTotal>("Sex,Count=count(*)").ToList(); //SELECT Sex,Count=count(*) FROM Student WHERE 1=1 AND (id < 20) GROUP BY Sex --生成结果 //2表关联查询 var jList = db.Queryable <Student>() .JoinTable <Student, School>((s1, s2) => s1.sch_id == s2.id) //默认left join .Where <Student, School>((s1, s2) => s1.id == 1) .Select("s1.*,s2.name as schName") .ToDynamic(); /*等于同于 * SELECT s1.*,s2.name as schName * FROM [Student] s1 * LEFT JOIN [School] s2 ON s1.sch_id = s2.id * WHERE s1.id = 1 */ //2表关联查询并分页 var jList2 = db.Queryable <Student>() .JoinTable <Student, School>((s1, s2) => s1.sch_id == s2.id) //默认left join //如果要用inner join这么写 //.JoinTable<Student, School>((s1, s2) => s1.sch_id == s2.id ,JoinType.INNER) .Where <Student, School>((s1, s2) => s1.id > 1) .OrderBy <Student, School>((s1, s2) => s1.name) .Skip(10) .Take(20) .Select("s1.*,s2.name as schName") .ToDynamic(); //3表查询并分页 var jList3 = db.Queryable <Student>() .JoinTable <Student, School>((s1, s2) => s1.sch_id == s2.id) // left join School s2 on s1.id=s2.id .JoinTable <Student, School>((s1, s3) => s1.sch_id == s3.id) // left join School s3 on s1.id=s3.id .Where <Student, School>((s1, s2) => s1.id > 1) // where s1.id>1 .Where <Student>(s1 => s1.id > 0) .OrderBy <Student, School>((s1, s2) => s1.id) //order by s1.id 多个order可以 .oderBy().orderby 叠加 .Skip(10) .Take(20) .Select("s1.*,s2.name as schName,s3.name as schName2")//select目前只支持这种写法 .ToDynamic(); //上面的方式都是与第一张表join,第三张表想与第二张表join写法如下 List <classNew> jList4 = db.Queryable <Student>() .JoinTable <Student, School>((s1, s2) => s1.sch_id == s2.id) // left join School s2 on s1.id=s2.id .JoinTable <Student, School, Area>((s1, s2, a1) => a1.id == s2.AreaId) // left join Area a1 on a1.id=s2.AreaId .Select <Student, School, Area, classNew>((s1, s2, a1) => new classNew { newid = s1.id, studentName = s1.name, schoolName = s2.name, areaName = a1.name }).ToList(); //最多支持5表查询,太过复杂的建议用Sqlable或者SqlQuery,我们的Queryable只适合轻量级的查询 //拼接 var queryable = db.Queryable <Student>().Where(it => true); if (maxId.ObjToInt() == 1) { queryable.Where(it => it.id == 1); } else { queryable.Where(it => it.id == 2); } var listJoin = queryable.ToList(); //queryable和SqlSugarClient解耦 var par = new Queryable <Student>().Where(it => it.id == 1);//声名没有connection对象的Queryable par.DB = db; var listPar = par.ToList(); } }
/// <summary> /// 多表查询 /// </summary> private void SqlableDemo() { using (var db = SugarDao.GetInstance()) { //---------Sqlable,创建多表查询---------// //多表查询 List <School> dataList = db.Sqlable() .From("school", "s") .Join("student", "st", "st.id", "s.id", JoinType.INNER) .Join("student", "st2", "st2.id", "st.id", JoinType.LEFT) .Where("s.id>100 and s.id<@id") .Where("1=1")//可以多个WHERE .OrderBy("ID") .SelectToList <School /*新的Model我这里没有所以写的School*/>("st.*", new { id = 1 }); //多表分页 List <School> dataPageList = db.Sqlable() .From("school", "s") .Join("student", "st", "st.id", "s.id", JoinType.INNER) .Join("student", "st2", "st2.id", "st.id", JoinType.LEFT) .Where("s.id>100 and s.id<100") .SelectToPageList <School>("st.*", "s.id", 1, 10); //多表分页WHERE加子查询 List <School> dataPageList2 = db.Sqlable() .From("school", "s") .Join("student", "st", "st.id", "s.id", JoinType.INNER) .Join("student", "st2", "st2.id", "st.id", JoinType.LEFT) .Where("s.id>100 and s.id<100 and s.id in (select 1 )" /*这里面写子查询都可以*/) .SelectToPageList <School>("st.*", "s.id", 1, 10); //--------转成List Dynmaic 或者 Json-----// //不分页 var list1 = db.Sqlable().From("student", "s").Join("school", "l", "s.sch_id", "l.id and l.id=@id", JoinType.INNER).SelectToDynamic("*", new { id = 1 }); var list2 = db.Sqlable().From("student", "s").Join("school", "l", "s.sch_id", "l.id and l.id=@id", JoinType.INNER).SelectToJson("*", new { id = 1 }); var list3 = db.Sqlable().From("student", "s").Join("school", "l", "s.sch_id", "l.id and l.id=@id", JoinType.INNER).SelectToDataTable("*", new { id = 1 }); //分页 var list4 = db.Sqlable().From("student", "s").Join("school", "l", "s.sch_id", "l.id and l.id=@id", JoinType.INNER).SelectToPageDynamic("s.*", "l.id", 1, 10, new { id = 1 }); var list5 = db.Sqlable().From("student", "s").Join("school", "l", "s.sch_id", "l.id and l.id=@id", JoinType.INNER).SelectToPageTable("s.*", "l.id", 1, 10, new { id = 1 }); var list6 = db.Sqlable().From("student", "s").Join("school", "l", "s.sch_id", "l.id and l.id=@id", JoinType.INNER).SelectToPageDynamic("s.*", "l.id", 1, 10, new { id = 1 }); //--------拼接-----// Sqlable sable = db.Sqlable().From <Student>("s").Join <School>("l", "s.sch_id", "l.id", JoinType.INNER); string name = "a"; int id = 1; if (!string.IsNullOrEmpty(name)) { sable = sable.Where("s.name=@name"); } if (!string.IsNullOrEmpty(name)) { sable = sable.Where("s.id=@id or s.id=100"); } if (id > 0) { sable = sable.Where("l.id in (select top 10 id from school)");//where加子查询 } var pars = new { id = id, name = name }; int pageCount = sable.Count(pars); var list7 = sable.SelectToPageList <Student>("s.*", "l.id desc", 1, 20, pars); } }
/// <summary> /// 单表查询 /// </summary> private void QueryableDemo() { using (var db = SugarDao.GetInstance()) { //---------Queryable<T>,扩展函数查询---------// //针对单表或者视图查询 //查询所有 var student = db.Queryable <Student>().ToList(); var studentDynamic = db.Queryable <Student>().ToDynamic(); var studentJson = db.Queryable <Student>().ToJson(); //查询单条 var single = db.Queryable <Student>().Single(c => c.id == 1); //查询单条没有记录返回空对象 var single2 = db.Queryable <Student>().Where(c => c.id == 1).SingleOrDefault(); //查询第一条 var first = db.Queryable <Student>().Where(c => c.id == 1).First(); var first2 = db.Queryable <Student>().Where(c => c.id == 1).FirstOrDefault(); //取10-20条 var page1 = db.Queryable <Student>().Where(c => c.id > 10).OrderBy("id").Skip(10).Take(20).ToList(); //上一句的简化写法,同样取10-20条 var page2 = db.Queryable <Student>().Where(c => c.id > 10).OrderBy("id").ToPageList(2, 10); //查询条数 var count = db.Queryable <Student>().Where(c => c.id > 10).Count(); //从第2条开始以后取所有 var skip = db.Queryable <Student>().Where(c => c.id > 10).OrderBy("id").Skip(2).ToList(); //取前2条 var take = db.Queryable <Student>().Where(c => c.id > 10).OrderBy("id").Take(2).ToList(); // Not like string conval = "a"; var notLike = db.Queryable <Student>().Where(c => !c.name.Contains(conval.ToString())).ToList(); //Like conval = "三"; var like = db.Queryable <Student>().Where(c => c.name.Contains(conval)).ToList(); // 可以在拉姆达使用 ToString和 Convert,比EF出色的地方 var convert1 = db.Queryable <Student>().Where(c => c.name == "a".ToString()).ToList(); var convert2 = db.Queryable <Student>().Where(c => c.id == Convert.ToInt32("1")).ToList();// var convert3 = db.Queryable <Student>().Where(c => DateTime.Now > Convert.ToDateTime("2015-1-1")).ToList(); var convert4 = db.Queryable <Student>().Where(c => DateTime.Now > DateTime.Now).ToList(); //支持字符串Where 让你解决,更复杂的查询 var student12 = db.Queryable <Student>().Where(c => "a" == "a").Where("id>100").ToList(); var student13 = db.Queryable <Student>().Where(c => "a" == "a").Where("id>100 and id in( select 1)").ToList(); //存在记录反回true,则否返回false bool isAny100 = db.Queryable <Student>().Any(c => c.id == 100); bool isAny1 = db.Queryable <Student>().Any(c => c.id == 1); int maxId = db.Queryable <Student>().Max <Student, int>("id"); int minId = db.Queryable <Student>().Where(c => c.id > 0).Min <Student, int>("id"); //In var list1 = db.Queryable <Student>().In("id", "1", "2", "3").ToList(); var list2 = db.Queryable <Student>().In("id", new string[] { "1", "2", "3" }).ToList(); var list3 = db.Queryable <Student>().In("id", new List <string> { "1", "2", "3" }).ToList(); var list4 = db.Queryable <Student>().Where(it => it.id < 10).In("id", new List <string> { "1", "2", "3" }).ToList(); //分组查询 var list5 = db.Queryable <Student>().Where(c => c.id < 20).GroupBy("sex").Select <Student, SexTotal>("Sex,Count=count(*)").ToList(); //SELECT Sex,Count=count(*) FROM Student WHERE 1=1 AND (id < 20) GROUP BY Sex --生成结果 } }
/// <summary> /// 单表查询 /// </summary> private void QueryableDemo() { using (var db = SugarDao.GetInstance()) { //---------Queryable<T>,扩展函数查询---------// //针对单表或者视图查询 //查询所有 var student = db.Queryable <Student>().ToList(); var studentDynamic = db.Queryable <Student>().ToDynamic(); var studentJson = db.Queryable <Student>().ToJson(); //查询单条 var single = db.Queryable <Student>().Single(c => c.id == 1); //查询单条没有记录返回空对象 var single2 = db.Queryable <Student>().Where(c => c.id == 1).SingleOrDefault(); //查询第一条 var first = db.Queryable <Student>().Where(c => c.id == 1).First(); var first2 = db.Queryable <Student>().Where(c => c.id == 1).FirstOrDefault(); //取10-20条 var page1 = db.Queryable <Student>().Where(c => c.id > 10).OrderBy(it => it.id).Skip(10).Take(20).ToList(); //上一句的简化写法,同样取10-20条 var page2 = db.Queryable <Student>().Where(c => c.id > 10).OrderBy(it => it.id).ToPageList(2, 10); //查询条数 var count = db.Queryable <Student>().Where(c => c.id > 10).Count(); //从第2条开始以后取所有 var skip = db.Queryable <Student>().Where(c => c.id > 10).OrderBy(it => it.id).Skip(2).ToList(); //取前2条 var take = db.Queryable <Student>().Where(c => c.id > 10).OrderBy(it => it.id).Take(2).ToList(); // Not like string conval = "a"; var notLike = db.Queryable <Student>().Where(c => !c.name.Contains(conval.ToString())).ToList(); //Like conval = "三"; var like = db.Queryable <Student>().Where(c => c.name.Contains(conval)).ToList(); // 可以在拉姆达使用 ToString和 Convert,比EF出色的地方 var convert1 = db.Queryable <Student>().Where(c => c.name == "a".ToString()).ToList(); var convert2 = db.Queryable <Student>().Where(c => c.id == Convert.ToInt32("1")).ToList();// var convert3 = db.Queryable <Student>().Where(c => DateTime.Now > Convert.ToDateTime("2015-1-1")).ToList(); var convert4 = db.Queryable <Student>().Where(c => DateTime.Now > DateTime.Now).ToList(); //支持字符串Where 让你解决,更复杂的查询 var student12 = db.Queryable <Student>().Where(c => "a" == "a").Where("id>100").ToList(); var student13 = db.Queryable <Student>().Where(c => "a" == "a").Where("id>100 and id in( select 1)").ToList(); //存在记录反回true,则否返回false bool isAny100 = db.Queryable <Student>().Any(c => c.id == 100); bool isAny1 = db.Queryable <Student>().Any(c => c.id == 1); //获取最大Id object maxId = db.Queryable <Student>().Max(it => it.id); int maxId1 = db.Queryable <Student>().Max(it => it.id).ObjToInt(); //拉姆达 int maxId2 = db.Queryable <Student>().Max <Student, int>("id"); //字符串写法 //获取最小 int minId1 = db.Queryable <Student>().Where(c => c.id > 0).Min(it => it.id).ObjToInt(); //拉姆达 int minId2 = db.Queryable <Student>().Where(c => c.id > 0).Min <Student, int>("id"); //字符串写法 //order By var orderList = db.Queryable <Student>().OrderBy("id desc,name asc").ToList(); //字符串支持多个排序 //可以多个order by表达示 var order2List = db.Queryable <Student>().OrderBy(it => it.name).OrderBy(it => it.id, OrderByType.desc).ToList(); // order by name as ,order by id desc //In var intArray = new[] { "5", "2", "3" }; var intList = intArray.ToList(); var list0 = db.Queryable <Student>().In(it => it.id, 1, 2, 3).ToList(); var list1 = db.Queryable <Student>().In(it => it.id, intArray).ToList(); var list2 = db.Queryable <Student>().In("id", intArray).ToList(); var list3 = db.Queryable <Student>().In(it => it.id, intList).ToList(); var list4 = db.Queryable <Student>().In("id", intList).ToList(); //分组查询 var list7 = db.Queryable <Student>().Where(c => c.id < 20).GroupBy(it => it.sex).Select("sex,Count=count(*)").ToDynamic(); var list8 = db.Queryable <Student>().Where(c => c.id < 20).GroupBy(it => it.sex).GroupBy(it => it.id).Select("id,sex,Count=count(*)").ToDynamic(); List <SexTotal> list9 = db.Queryable <Student>().Where(c => c.id < 20).GroupBy(it => it.sex).Select <Student, SexTotal>("Sex,Count=count(*)").ToList(); List <SexTotal> list10 = db.Queryable <Student>().Where(c => c.id < 20).GroupBy("sex").Select <Student, SexTotal>("Sex,Count=count(*)").ToList(); //SELECT Sex,Count=count(*) FROM Student WHERE 1=1 AND (id < 20) GROUP BY Sex --生成结果 } }