学习SQLSugar，分享给更多人收益_sqlsugar 模糊查询

简单查询

static SugarDbContext sugar = new SugarDbContext();

        static void Main(string[] args)

        {

            var db = sugar.Db;

            //查询所有

            var AllStudent = db.Queryable<Student>().ToList();

            //取前5条

            var top5 = db.Queryable<Student>().Take(5).ToList();

            //无锁查询

            var getAllNoLock = db.Queryable<Student>().With(SqlWith.NoLock).ToList();

            //根据主键查询

            var getByPrimaryKey = db.Queryable<Student>().InSingle("0000d82f-b1f2-4c7d-a3b9-6c70f9678282");

            //查询单条没有数据返回NULL, Single超过1条会报错，First不会

            //var getSingleOrDefault = db.Queryable<Student>().Single(); //会报错，数据量大于一条

            var getSingleOrDefault = db.Queryable<Student>().Where(A=>A.StudentID== "0000d82f-b1f2-4c7d-a3b9-6c70f9678282").Single();

            var getFirstOrDefault = db.Queryable<Student>().First();

            //UNION ALL Count = 2420838  240多万条数据

            var UNIONLst = db.UnionAll<Student>(db.Queryable<Student>(), db.Queryable<Student>()).ToList();

            //in 查询

            var in1 = db.Queryable<Student>().In(A => A.StudentID, new string[] { "000136bf-f968-4a59-9091-bae8ebca42fb", "00020ba7-44e6-494c-8fcb-c1be288a39b3" }).ToList();

            //主键 In (1,2,3)  不指定列, 默认根据主键In

            var in2 = db.Queryable<Student>().In(new string[] { "000136bf-f968-4a59-9091-bae8ebca42fb", "00020ba7-44e6-494c-8fcb-c1be288a39b3" }).ToList();

            //in 查询

            List<string> array = new List<string>{ "000136bf-f968-4a59-9091-bae8ebca42fb", "00020ba7-44e6-494c-8fcb-c1be288a39b3" };

            var in3 = db.Queryable<Student>().Where(it => array.Contains(it.StudentID)).ToList();

            //not in

            var in4 = db.Queryable<Student>().Where(it => !array.Contains(it.StudentID)).ToList();

            //where

            var getByWhere = db.Queryable<Student>().Where(it => it.StudentID == "000136bf-f968-4a59-9091-bae8ebca42fb" || it.StudentName == "陈丽").ToList();

            //SqlFunc

            var getByFuns = db.Queryable<Student>().Where(it => SqlFunc.IsNullOrEmpty(it.StudentName)).ToList();

            //between and

            var between = db.Queryable<Student>().Where(it => SqlFunc.Between(it.CreateTime, DateTime.Now.AddDays(-10), DateTime.Now)).ToList();

            //排序

            var getAllOrder = db.Queryable<Student>().Take(100).OrderBy(it => it.CreateTime).ToList(); //默认为ASC排序

            //组合排序

            var data = db.Queryable<Student>()

                .OrderBy(it => it.StudentName, OrderByType.Asc)

                .OrderBy(it => it.CreateTime, OrderByType.Desc)

                .ToList();

            //是否存在 any

            var isAny = db.Queryable<Student>().Where(it => it.StudentName == "张龙").Any();

            var isAny2 = db.Queryable<Student>().Any(it => it.StudentSex == "女");

            //获取同一天的记录

             var getTodayList = db.Queryable<Student>().Where(it => SqlFunc.DateIsSame(it.CreateTime, DateTime.Now)).ToList();

            Console.ReadLine();

        }

多表查询

class Program

    {

        static SugarDbContext sugar = new SugarDbContext();

        static void Main(string[] args)

        {

            var db = sugar.Db;

            var list = db.Queryable<Student, StudentGrad>((st, sc) => new object[] {

                        JoinType.Inner,st.GradID==sc.GradID})

                        .Select((st, sc) => new { StudentName = st.StudentName, GradName = sc.GradName }).ToList();

            var list2 = db.Queryable<Student, StudentGrad>((st, sc) => new object[] {

                        JoinType.Inner,st.GradID==sc.GradID})

                      .Select((st, sc) => new ViewModel { StudentName = st.StudentName, GradName = sc.GradName }).ToList();

            ///3张表关联查询

            //var list3 = db.Queryable<Student, School, Student>((st, sc, st2) => new object[] {

            //  JoinType.Left,st.SchoolId==sc.Id,

            //  JoinType.Left,st.SchoolId==st2.Id

            //})

            //         .Where((st, sc, st2) => st2.Id == 1 || sc.Id == 1 || st.Id == 1)

            //         .OrderBy((sc) => sc.Id)

            //         .OrderBy((st, sc) => st.Name, OrderByType.Desc)

            //         .Select((st, sc, st2) => new { st = st, sc = sc }).ToList();

            ///分页查询

            var pageIndex = 1;

            var pageSize = 10;

            var list4 = db.Queryable<Student, StudentGrad>((st, sc) => new object[] {

              JoinType.Left,st.GradID==sc.GradID

            }).Select((st, sc) => new ViewModel { StudentName = st.StudentName, GradName = sc.GradName })

           .ToPageList(pageIndex, pageSize);

            foreach(var item in list4)

            {

                Console.WriteLine(item.GradName + item.StudentName);

            }      

            ///五张表关联查询

            //var list2 = db.Queryable<Student, School, Student, Student, Student>((st, sc, st2, st3, st4) => new object[] {

            //  JoinType.Left,st.SchoolId==sc.Id,

            //  JoinType.Left,st.Id==st2.Id,

            //  JoinType.Left,st.Id==st3.Id,

            //  JoinType.Left,st.Id==st4.Id

            //}).Where((st, sc) => sc.Id == 1)

            // .Select((st, sc, st2, st3, st4) => new { id = st.Id, name = st.Name, st4 = st4 }).ToList();

            ///二个Queryable的Join(4.6.0.9)

            var q1 = db.Queryable<Student>();

            var q2 = db.Queryable<StudentGrad>();

            var innerJoinList = db.Queryable(q1, q2, (j1, j2) => j1.GradID == j2.GradID).Select((j1, j2) => j1).ToList();//inner join

            ///多表查询的简化 默认为inner join

            var list5 = db.Queryable<Student, StudentGrad>((st, sc) => st.GradID == sc.GradID).Select((st, sc) => new ViewModel { StudentName= st.StudentName, GradName= sc.GradName}).ToList();

            ///3表查询

            //var list6 = db.Queryable<Student, School, School>((st, sc, sc2) => st.SchoolId == sc.Id && sc.Id == sc2.Id)

            //    .Select((st, sc, sc2) => new { st.Name, st.Id, schoolName = sc.Name, schoolName2 = sc2.Name }).ToList();

            ///3表查询分页

            //var list7 = db.Queryable<Student, School, School>((st, sc, sc2) => st.SchoolId == sc.Id && sc.Id == sc2.Id)

            //.Select((st, sc, sc2) => new { st.Name, st.Id, schoolName = sc.Name, schoolName2 = sc2.Name }).ToPageList(1, 2);

            ///qlFunc.Subqueryable 子查询

//            var getAll = db.Queryable<Student, School>((st, sc) => new object[] {

//JoinType.Left,st.Id==sc.Id})

//.Where(st => st.Id == SqlFunc.Subqueryable<School>().Where(s => s.Id == st.Id).Select(s => s.Id))

//.ToList();

//            //生成的MYSQL语句，如果是SqlServer就是TOP 1

//            SELECT `st`.`ID`,`st`.`SchoolId`,`st`.`Name`,`st`.`CreateTime`

//     FROM `STudent` st Left JOIN `School` sc ON( `st`.`ID` = `sc`.`Id` ) 

//      WHERE( `st`.`ID` = (SELECT `Id` FROM `School` WHERE( `Id` = `st`.`ID` ) limit 0, 1))

            Console.ReadLine();

        }

    }

    class ViewModel

    {  

        public string StudentName { get; set; } 

        public string GradName { get; set; }

    }

查询函数

class Program

    {

        static SugarDbContext sugar = new SugarDbContext();

        static void Main(string[] args)

        {

            var db = sugar.Db;

            ///SqlFunc.ToLower 小写

            var slst = db.Queryable<Student>().Where(it => SqlFunc.ToLower(it.StudentName) == SqlFunc.ToLower("JACK")).ToList();

            ///qlFunc.ToUpper 大写

            var slst_2 = db.Queryable<Student>().Where(it => SqlFunc.ToUpper(it.StudentName) == "JACK").ToList();

            var slst_21 = db.Queryable<Student>().Where(it => it.StudentName == "JACK").ToList();

            ///三元判段 ，相当于 it.id==1?1:2

            var slst_3 = db.Queryable<Student>().Where(it => SqlFunc.ToLower(it.StudentName) == SqlFunc.ToLower("JACK")).Select(A =>new StuModel { StudentName= SqlFunc.IIF(A.StudentName == "JACK", "杰克", "其他") , StuSex=A.StudentSex} ).ToList();

            ///if else end 4.6.0.1

            var slst_4 = db.Queryable<Student>().Where(it => SqlFunc.ToLower(it.StudentName).Contains("tom") ).Select(A => new StuModel { StudentName = SqlFunc.IF(A.StudentName=="tom1")

             .Return("大汤姆")

             .ElseIF(A.StudentName== "tom2")

             .Return("中汤姆").End("小汤姆"), StuSex = A.StudentSex }).ToList();

            foreach(var item in slst_4)

            {

                Console.WriteLine(item.StudentName);

            }

            ///ISNULL 查询

            ///IsNullOrEmpty 判段是NULL或者空

            ///SqlFunc.HasValue 判段不是NULL并且不是空

            ///SqlFunc.HasNumber 判段大于0并且不等于NULL

            ///SqlFunc.Trim 去空格

            var slst_5 = db.Queryable<Student>().Where(A => A.StudentID == "00013a00-9067-40c1-be2a-a06fea47c632").Select(A => new StuModel { StudentName = SqlFunc.IsNull(A.StudentName, "暂无姓名"), StuSex = A.StudentSex }).ToList();

            foreach (var item in slst_5)

            {

                Console.WriteLine(item.StudentName);

            }

            ///获取数据库时间 SqlFunc.GetDate()

            //var tim = SqlFunc.GetDate();//会报错

            var date = DateTime.Now.AddDays(-10);

            var slst_6 = db.Queryable<Student>().Where(A => SqlFunc.Between(A.CreateTime, date, SqlFunc.GetDate())).ToList();

            Console.WriteLine(slst_6.Count);

            ///Contains 模糊查询 like %@p%

            ///StartsWith 模糊查询 like %@p%

            ///EndsWith 模糊查询 like %@p%

            ///

            var slst_7 = db.Queryable<Student>().Where(A =>A.StudentName.EndsWith("婷") ).ToList();

            ///等于 SqlFunc.Equals(object thisValue, object parameterValue)

            ///是否是同一天 SqlFunc.DateIsSame(DateTime date1, DateTime date2)

            ///是否是同一时间 （dataType 可以是年、月、天、小时、分钟、秒和毫秒） SqlFunc.DateIsSame(DateTime date1, DateTime date2, DateType dataType)

            ///在当前时间加一定时间（dataType 可以是年、月、天、小时、分钟、秒和毫秒） SqlFunc.DateAdd(DateTime date, int addValue, DateType dataType)

            ///在当前时间加N天 SqlFunc.DateAdd(DateTime date, int addValue)

            ///获取当前时间的年、月、天、小时、分钟、秒或者毫秒 SqlFunc.DateValue(DateTime date, DateType dataType)

            ///范围判段 SqlFunc.Between(object value, object start, object end)

            ///

            var slst_8 = db.Queryable<Student>().Where(A =>SqlFunc.DateAdd(Convert.ToDateTime(A.CreateTime),1,DateType.Day)>Convert.ToDateTime("2020-10-23")).ToList();

            ///类型转换

            ///

            /*

            SqlFunc.ToInt32(object value)

            SqlFunc.ToInt64(object value)

            SqlFunc.ToDate(object value)

            SqlFunc.ToString(object value)

            SqlFunc.ToDecimal(object value)

            SqlFunc.ToGuid(object value)

            SqlFunc.ToDouble(object value)

            SqlFunc.ToBool(object value)

            */

            ///

            ///截取字符串 SqlFunc.Substring(object value, int index, int length)

            ///替换字符串 SqlFunc.Replace(object value, string oldChar, string newChar)

            ///获取字符串长度 SqlFunc.Length(object value)

            ///

            ///聚合函数

            /*

             SqlFunc.AggregateSum<TResult>(TResult thisValue)

             SqlFunc.AggregateAvg<TResult>(TResult thisValue)

             SqlFunc.AggregateMin(TResult thisValue)

             SqlFunc.AggregateMax<TResult>(TResult thisValue)

             SqlFunc.AggregateCount<TResult>(TResult thisValue)

             */

            ///

            var slst_9 = db.Queryable<Student>().Select(A => SqlFunc.AggregateMax<DateTime?>(A.CreateTime)).ToList();

            var slst_91 = db.Queryable<Student>().Select(A => SqlFunc.AggregateMax(A.CreateTime)).ToList();

            var slst_10 = db.Queryable<Student>().Select(A => SqlFunc.AggregateMin(A.CreateTime)).ToList();

            Console.ReadLine();

        }

    }

    class ViewModel

    {  

        public string StudentName { get; set; } 

        public string GradName { get; set; }

    }

    class StuModel

    {

        public string StudentName { get; set; }

        public string StuSex { get; set; }

    }

动态查询

using SqlSugar;

using Sugar.Enties;

using SugarContext;

using System;

using System.Collections.Generic;

using System.Diagnostics;

namespace SugarCore

{

    class Program

    {

        static SugarDbContext sugar = new SugarDbContext();

        static void Main(string[] args)

        {

            var db = sugar.Db;

            var queryable = db.Queryable<Student>();

            //拼接会比EF方便些，不像EF需要queryable+=

            queryable.Where(it => it.StudentName.Contains("陈"));

            queryable.Where(it => it.StudentSex == "女");

            //防止queryable相互影响我们用clone解决

            var StudentName = queryable.Clone().Select(it => it.StudentName).First();

            /正确答案是两条数据 如果去掉Clone，受上面一条影响，只会有一条数据

            var list = queryable.Clone().ToList();//正确答案是两条数据 如果去掉Clone，受上面一条影响，只会有一条数据

            ///案例1： WhereIF函数

            ///根据条件判段是否执行过滤，我们可以用WhereIf来实现，true执行过滤，false则不执行

            ///

            var a = "陈";

            var b = "飞";

            var c = "女";

            ///陈性女同学一个

            var list2 = db.Queryable<Student>()

    .WhereIF(!string.IsNullOrEmpty(a), it => it.StudentName.StartsWith(a))

    .WhereIF(!string.IsNullOrEmpty(b), it => it.StudentName.EndsWith(b))

    .WhereIF(!string.IsNullOrEmpty(c), it => it.StudentSex == c).ToList();

            //

            ///所有叫陈飞的童鞋9人   string.IsNullOrEmpty(c) 这个语句不会执行

            var list3 = db.Queryable<Student>()

    .WhereIF(!string.IsNullOrEmpty(a), it => it.StudentName.StartsWith(a))

    .WhereIF(!string.IsNullOrEmpty(b), it => it.StudentName.EndsWith(b))

    .WhereIF(string.IsNullOrEmpty(c), it => it.StudentName == c).ToList();

            ///

            /*

             案例2.：MergeTable 函数 4.4

             是将多表查询的结果Select里的内容变成一张表， 如果是多表查询的时候，我们无论是使用 where 还是 orderBy 都需要加别名，这样我们就不能实现动态排序，因为我不知道别名叫什么, 可以用MergeTable解决这个问题

             */

            ///多表查询方式

            var pageJoin = db.Queryable<Student, StudentGrad>((st, sc) => new object[]

                {

                  JoinType.Inner, st.GradID == sc.GradID

                })

                .Where(st => st.StudentName.EndsWith("芬"))//别名是st

                .OrderBy("st.StudentName asc")//别名是sc

                .Select((st, sc) => new { StudentName = st.StudentName, gradeName = sc.GradName })

                .ToList();

            ///等同于MergeTable 方式

            ///

            var pageJoin_2 = db.Queryable<Student, StudentGrad>((st, sc) => new object[]

                                {

                                    JoinType.Inner,st.GradID==sc.GradID

                                })

                                .Select((st, sc) => new

                                {

                                    StudentName = st.StudentName,

                                    gradeName = sc.GradName

                                })

                                .MergeTable()

                                .Where(A => A.StudentName.EndsWith("芬")).OrderBy("StudentName asc").ToList();//别名不限

            ///案例3： SqlQueryable 4.5.2.5 , 可以方便的把SQL变成表来操作 直接执行SQL语句

            ///

            var t12 = db.SqlQueryable<Student>("select * from student").ToPageList(1, 2);

            ///案例4： 将表单组装成 List<ConditionalModel>实现查询 4.5.9

            ///查询女生中 带有 飞 子的同学

            List<IConditionalModel> conModels = new List<IConditionalModel>();

            conModels.Add(new ConditionalModel() { FieldName = "StudentSex", ConditionalType = ConditionalType.Equal, FieldValue = "女" });

            conModels.Add(new ConditionalModel() { FieldName = "StudentName", ConditionalType = ConditionalType.Like, FieldValue = "飞" });

            var student = db.Queryable<Student>().Where(conModels).ToList();

            ///

            //4.6.4.4 版本支持了 复杂的OR

            // and StudentSex='女' And (StudentName='陈芬' or StudentName='王芬' Or StudentName='李芬')

            List<IConditionalModel> conModels__22 = new List<IConditionalModel>();

            conModels__22.Add(new ConditionalModel() { FieldName = "StudentSex", ConditionalType = ConditionalType.Equal, FieldValue = "女" });

            conModels__22.Add(new ConditionalCollections()

            {

                ConditionalList =

            new List<KeyValuePair<WhereType, SqlSugar.ConditionalModel>>()

            {

    new  KeyValuePair<WhereType, ConditionalModel>

    ( WhereType.And , //And

    new ConditionalModel() { FieldName = "StudentName", ConditionalType = ConditionalType.Equal, FieldValue = "陈芬" }),

    new  KeyValuePair<WhereType, ConditionalModel>

    (WhereType.Or,

    new ConditionalModel() { FieldName = "StudentName", ConditionalType = ConditionalType.Equal, FieldValue = "王芬" }),

    new  KeyValuePair<WhereType, ConditionalModel>

    ( WhereType.Or,

    new ConditionalModel() { FieldName = "StudentName", ConditionalType = ConditionalType.Equal, FieldValue = "李芬" })

            }

            });

            var studentResult = db.Queryable<Student>().Where(conModels__22).ToList();

            ///案例5: 拼接拉姆达 4.5.9.8

            ///

            var exp = Expressionable.Create<Student>()

      .OrIF(1 == 1, it => it.StudentSex == "女")

      .And(it => it.StudentName.Contains("陈"))

      .AndIF(2 == 3, it => SqlFunc.IsNullOrEmpty(it.StudentName)) //此where 不执行

      .Or(it => it.StudentName.Contains("飞")).ToExpression();//拼接表达式

            var list55 = db.Queryable<Student>().Where(exp).ToList();

            ///Queryable是支持字符串与拉姆达混用或者纯字符串拼接模式，可以满足复杂的一些需求

            ///复杂动态 表达式和SQL子查询混合模式

            ///

            例子1:

                var queryable = db.Queryable<Student>("t");

                queryable.Where("t.id in (select id from xxx)");

                queryable.Where(it => it.Id == 1);

                //更多操作拼接qureyable 

                var result = queryable.Select(@"

                      id,

                      name,

                      (select name form school where shoolid=t.id) as schoolName

                       ").ToList();

            例子2:

                dynamic join3 = db.Queryable("Student", "st")

                        .AddJoinInfo("School", "sh", "sh.id=st.schoolid")

                        .Where("st.id>@id")

                        .AddParameters(new { id = 1 })

                        .Select("st.*").ToList(); //也可以Select<T>(“*”).ToList()返回实体集合

            例子3:

                var list = db.Queryable<Student>().

                                Select(it => new Student()

                                {

                                    Name = it.Name,

                                    Id = SqlFunc.MappingColumn(it.Id, "(select top 1 id from school)") // 动态子查询

                    }).ToList();

            ///安全拼SQL

            ///安全拼SQL 安全拼SQL 安全拼SQL 安全拼SQL 安全拼SQL 安全拼SQL 安全拼SQL 安全拼SQL 安全拼SQL

                        安全拼SQL

            使用参数化过滤

            private static void Where()

                        {

                            var db = GetInstance();

                            string value = "'jack';drop table Student";

                            var list = db.Queryable<Student>().Where("name=@name", new { name = value }).ToList();

                            //没有发生任何事情

                        }

                        字段是无法用参数化实现的，我们就可以采用这种方式过滤

            private static void OrderBy()

                        {

                            var db = GetInstance();

                            try

                            {

                                var propertyName = "Id'"; //类中的属性的名称

                                var dbColumnName = db.EntityProvider.GetDbColumnName<Student>(propertyName);

                                var list2 = db.Queryable<Student>().OrderBy(dbColumnName).ToList();

                            }

                            catch (Exception ex)

                            {

                                Console.WriteLine(ex.Message);

                            }

                        }

            Console.ReadLine();

        }

    }

    class ViewModel

    {  

        public string StudentName { get; set; } 

        public string GradName { get; set; }

    }

    class StuModel

    {

        public string StudentName { get; set; }

        public string StuSex { get; set; }

    }

}

分组查询

1.分组查询

var group = db.Queryable<Student>().GroupBy(it => it.Id)

    .Having(it => SqlFunc.AggregateCount(it.Id) > 10)

    .Select(it => new { id = SqlFunc.AggregateCount(it.Id) }).ToList();

多个GroupBy写法如下

var group = db.Queryable<Student>().GroupBy(it => it.Id).GroupBy(it => it.Type)

    .Having(it => SqlFunc.AggregateCount(it.Id) > 10)

    .Select(it => new { id = SqlFunc.AggregateCount(it.Id) }).ToList();

还可以

.GroupBy(it => new {it.Id,it.Type})

2.简单去重

var list3 = db.Queryable<Student>()

.GroupBy(it => new { it.Id, it.Name }).Select(it=>new{ it.id,it.Name}).ToList();

// 性能优于 select distinct id,name from student所以我暂不支持distinct去重，结果是一样的

3.去重并且返回所有列(分组第一条)

group by只能返回特定列，PartitionBy可以返回所有列

var list3 = db.Queryable<Student>()

.PartitionBy(it => new { it.Id, it.Name }).Take(1).ToList();

分页查询

var db = GetInstance();

var pageIndex = 1;

var pageSize = 2;

var totalCount = 0;

单表分页

var page = db.Queryable<Student>().OrderBy(it => it.Id).ToPageList(pageIndex, pageSize, ref totalCount);

多表分页

var pageJoin = db.Queryable<Student, School>((st, sc) => new object[] {

    JoinType.Left,st.SchoolId==sc.Id

}).ToPageList(pageIndex, pageSize, ref totalCount);

取前5条

var top5 = db.Queryable<Student>().Take(5).ToList();

取前5条之后的所有数据

var skip5 = db.Queryable<Student>().Skip(5).ToList();

注意：SqlServer版本底层采用的是Rownumber分页，在排序字段有索引的情况下性能是最好的分页，优于12分页和TOP分页，

RowNumber分页是页码越小性能越快符合多数人的使用习惯，如果追求极限性能 当前码数 大于总页数的一半时可以采用倒序分页法实现对大页码的优化同样达到小页码的性能。

参考代码：

 

 //常规写法

 db.Queryable<Student>().OrderBy(it=>it.Id).ToPageList(pageIndex,pageSize);

 

 

 //针对rowNumber分页的优化写法，该写法可以达到分页最高性能，非对性能要求过高的可以不用这么写

 var Tempdb=db.Queryable<Student>();

 int count = Tempdb.Count();

                var Skip = (R.Page - 1) * R.PageCount;

                var Take = R.PageCount;

                if (R.Page*R.PageCount > P.Count / 2)//页码大于一半用倒序

                {

                    Tempdb.OrderBy(x => x.ID, OrderByType.Desc);

                    var Mod = P.Count % R.PageCount;

                    var Page = (int)Math.Ceiling((Decimal)P.Count / R.PageCount);

                    if (R.Page * R.PageCount >= P.Count)

                    {

                        Skip = 0; Take = Mod == 0 ? R.PageCount : Mod;

                    }

                    else

                    {

                        Skip = (Page - R.Page - 1) * R.PageCount + Mod;

                    }

                }

                else

                {

                    Tempdb.OrderBy(x => x.ID);//升序

                }

                Tempdb.Skip(Skip);

                Tempdb.Take(Take);

 var list=Tempdb.ToList();

事务

重要的事情说三遍：

事务只能在同一个SqlSugarClient对象有效,事务只能在同一个SqlSugarClient对象有效,事务只能在同一个SqlSugarClient对象有效，跨SqlSugarClient对象请用分布式事务

MySql特殊的库或表不支持事务，所以如果是用MYSQL的朋友需要注意了

正确用法：

用法1： 无数据返回只返回状态

var result = db.Ado.UseTran(() =>

{

    var beginCount = db.Queryable<Student>().Count();

    db.Ado.ExecuteCommand("delete student");

    //throw new Exception("error haha"); 测试代码

});

// result.ErrorException

// result.IsSuccess

用法2：返回数据并且返回状态

var result2 = db.Ado.UseTran<List<Student>>(() =>

{

    return db.Queryable<Student>().ToList();

});

// result.ErrorException

// result.IsSuccess

// result.Data

用法3： 使用try catch来处理事务，用这种方式事务一定要加try catch回滚不然会锁表，在操作就卡死

try

{

 db.Ado.BeginTran();

 操作

 db.Ado.CommitTran();

}

catch (Exception ex)

{

 db.Ado.RollbackTran();

 throw ex;

}

错误用法，创建了3个db对象

{9LGEVS(WE_8_6WJG4NO]3L.png

正确写法

var db=GetAll(); //GetAll是获取新的Db实例的方法

db.Ado.SqlQuery<T>(sql)

跨类事务方案

http://www.codeisbug.com/Doc/8/1158

4.7 异步事务的支持

因为Async方法在事务中无效所以对于多个SqlSugar方法进行事务操作并且能够实现异步增加了该功能

            //无返回值只返回状态

            var asyncResult = db.Ado.UseTranAsync(() =>

            {

                var beginCount = db.Queryable<Student>().ToList();

                db.Ado.ExecuteCommand("delete student");

                var endCount = db.Queryable<Student>().Count();

                throw new Exception("error haha");

            });

            asyncResult.Wait();

            var asyncCount = db.Queryable<Student>().Count();

            //有返回值和状态

            var asyncResult2 = db.Ado.UseTranAsync<List<Student>>(() =>

            {

                return db.Queryable<Student>().ToList();

            });

            asyncResult2.Wait();

和EF一样的事务用法

http://www.codeisbug.com/Doc/8/1174

执行SQL

Sqlqueryable

sqlueryable只支持查询操作，并且支持拉姆达分页

var t12 = db.SqlQueryable<Student>("select * from student").Where(it=>it.id>0).ToPageList(1, 2);

var t12 = db.SqlQueryable<dynamic>("select * from student").ToPageList(1, 2);//返回动态类型

Ado方法

1.重载：object parameters

var dt=db.Ado.SqlQuery<Student>("select * from table where id=@id and name=@name",new {id=1,name="a"});

var dt=db.Ado.SqlQuery<Student>("select * from table where id=@id and name=@name",字典);

2.重载： List<SugarParameter> parameters

var dt=db.Ado.GetDataTable("select * from table where id=@id and name=@name",new List<SugarParameter>(){

  new SugarParameter("@id",1),

  new SugarParameter("@name",2)

});

3.重载：params SugarParameter[] parameters

var dt=db.Ado.GetDataTable("select * from table");

var dt=db.Ado.GetDataTable("select * from table where id=@id",new SugarParameter("@id",1));

var dt=db.Ado.GetDataTable("select * from table where id=@id and name=@name",new SugarParameter []{

  new SugarParameter("@id",1),

  new SugarParameter("@name",2)

});

全部函数

1.获取DataTable (如是.Net Core版本, DataTable是Sqlsugar自定义的DataTable, 因为以前的Core 1.x不支持DataTable, 后遗症, 效率不用担心)

db.Ado.GetDataTable(string sql, object parameters);

db.Ado.GetDataTable(string sql, params SugarParameter[] parameters);

db.Ado.GetDataTable(string sql, List<SugarParameter> parameters);

2.获取DataSet

db.Ado.GetDataSetAll(string sql, object parameters);

db.Ado.GetDataSetAll(string sql, params SugarParameter[] parameters);

db.Ado.GetDataSetAll(string sql, List<SugarParameter> parameters);

3.获取DataReader

db.Ado.GetDataReader(string sql, object parameters);

db.Ado.GetDataReader(string sql, params SugarParameter[] parameters);

db.Ado.GetDataReader(string sql, List<SugarParameter> parameters);

4.获取首行首列返回object类型

db.Ado.GetScalar(string sql, object parameters);

db.Ado.GetScalar(string sql, params SugarParameter[] parameters);

db.Ado.GetScalar(string sql, List<SugarParameter> parameters);

5.执行数据库返回受影响行数

int ExecuteCommand(string sql, object parameters);

int ExecuteCommand(string sql, params SugarParameter[] parameters);

int ExecuteCommand(string sql, List<SugarParameter> parameters);

6.获取首行首列更多重载

//以下为返回string

string GetString(string sql, object parameters);

string GetString(string sql, params SugarParameter[] parameters);

string GetString(string sql, List<SugarParameter> parameters);

//返回int

int GetInt(string sql, object pars);

int GetInt(string sql, params SugarParameter[] parameters);

int GetInt(string sql, List<SugarParameter> parameters);

//返回double

db.Ado.GetDouble(string sql, object parameters);

db.Ado.GetDouble(string sql, params SugarParameter[] parameters);

db.Ado.GetDouble(string sql, List<SugarParameter> parameters);

//返回decimal

db.Ado.GetDecimal(string sql, object parameters);

db.Ado.GetDecimal(string sql, params SugarParameter[] parameters);

db.Ado.GetDecimal(string sql, List<SugarParameter> parameters);

//返回DateTime

db.Ado.GetDateTime(string sql, object parameters);

db.Ado.GetDateTime(string sql, params SugarParameter[] parameters);

db.Ado.GetDateTime(string sql, List<SugarParameter> parameters);

7.查询并返回List<T>

db.Ado.SqlQuery<T>(string sql, object whereObj = null);

db.Ado.SqlQuery<T>(string sql, params SugarParameter[] parameters);

db.Ado.SqlQuery<T>(string sql, List<SugarParameter> parameters);

8.查询返回单条记录

db.Ado.SqlQuerySingle<T>(string sql, object whereObj = null);

db.Ado.SqlQuerySingle<T>(string sql, params SugarParameter[] parameters);

db.Ado.SqlQuerySingle<T>(string sql, List<SugarParameter> parameters);

9.查询返回动态类型(该类型为Newtonsoft.Json里面的JObject类型, 使用方法自行百度)

db.Ado.SqlQueryDynamic(string sql, object whereObj = null);

db.Ado.SqlQueryDynamic(string sql, params SugarParameter[] parameters);

db.Ado.SqlQueryDynamic(string sql, List<SugarParameter> parameters);

存储过程

CommandType.Text方式

也就是SQL脚本的方式，这种方式是不能直接用存储过程名字去调用的，需要这样写

db.Ado.GetInt("exec spName @p1",new {p=1})

CommandType.StoredProcedure 方式

4.5.02版本支持

var dt2 = db.Ado.UseStoredProcedure().GetDataTable("sp_school",new{name="张三",age=0});//  GetInt SqlQuery<T>  等等都可以用

//支持output

var nameP= new SugarParameter("@name", "张三");

var ageP= new SugarParameter("@age", null, true);//isOutput=true

var dt2 = db.Ado.UseStoredProcedure().GetDataTable("sp_school",nameP,ageP);

//ageP.value可以拿到返回值

Oracle游标

 parameter.IsRefCursor =true;

我们还可以用 GetParameters 来简化参数操作

 string p=null;

 SugarParameter [] pars =db.Ado.GetParameters(new{p=1,p2=p});

 var p2= pars[1].Direction=ParameterDirection.Output;

插入

注意：

          Oracle反回自增列 在字段特性SugarColumn 可以设置序列名称

          SqlSever插量插入慢一般是建表语句带有Wtih(索引设置)引起的，把With删掉会很快

插入并返回受影响行数用ExecuteCommand

var t2 = db.Insertable(insertObj).ExecuteCommand();

插入并返回自增列用ExecuteReutrnIdentity

int t30 = db.Insertable(insertObj).ExecuteReturnIdentity();

long t31 = db.Insertable(insertObj).ExecuteReturnBigIdentity(); //4.5.0.2 +  long

4.2.3插入并返回实体 ,  只是自identity 添加到 参数的实体里面并返回，没有查2次库，所以有些默认值什么的变动是取不到的你们需要手动进行2次查询获取

var t3 = db.Insertable(insertObj).ExecuteReturnEntity();

4.5.0.2 插入并返回bool, 并将identity赋值到实体

var t3 = db.Insertable(insertObj).ExecuteCommandIdentityIntoEntity();

只插入列 Name和SchoolId

var t4 = db.Insertable(insertObj).InsertColumns(it => new { it.Name, it.SchoolId }).ExecuteReturnIdentity();

不插入列 Name和TestId

var t5 = db.Insertable(insertObj).IgnoreColumns(it => new { it.Name, it.TestId }).ExecuteReturnIdentity();

根据条件指定不插入列

var t6 = db.Insertable(insertObj).IgnoreColumns(it => it == "Name" || it == "TestId").ExecuteReturnIdentity();

List中所有列不插入

var t61 = db.Insertable(updateObj)

.IgnoreColumns(it => list.Contains(it)  ).ExecuteCommand();

使用锁

var t8 = db.Insertable(insertObj).With(SqlWith.UpdLock).ExecuteCommand();

可以设置NULL列不插入和是否强制插入自增列

var t9 = db.Insertable(insertObj2)

.Where(true/* Is no insert null */, true/*off identity*/)

.ExecuteCommand();

批量插入（性能很快不用操心）

var insertObjs = new List<Student>();

var s9 = db.Insertable(insertObjs.ToArray()).ExecuteCommand();

//注意 ： SqlSever 建表语句带有Wtih(设置)，如果设置不合理，可能会引起慢，把With删掉就会很快

4.2.2 匿名对象和字典的支持

var t12 = db.Insertable<Student>(new { Name = "a" }).ExecuteCommand();

//INSERT INTO [STudent]  ([Name]) VALUES ('a') ;SELECT SCOPE_IDENTITY();

 var t13 = db.Insertable<Student>(new Dictionary<string, object>() {{ "name","a"} }).ExecuteCommand();

//INSERT INTO [STudent]  ([Name]) VALUES ('a') ;SELECT SCOPE_IDENTITY();

4.6.4.8支持了不加泛型的字典

var dt = new Dictionary<string, object>();

dt.Add("name", "1");

var t66 = db.Insertable(dt).AS("student").ExecuteReturnIdentity();

4.6.1 插入数据库默认值

我们只要在实体上加上

[SugarColumn(IsOnlyIgnoreInsert=true)]

 public DateTime CreateTime { get; set; }

将A表数据插入B表

db.Insertable(db.Queryable<A>().Select<B>().ToList()).ExecuteCommand();

删除

根据实体删除（实体内主键一定要有值）

var t0 = db.Deleteable<Student>().Where(new Student() { Id = 1 }).ExecuteCommand();

根据实体集删除

var  t1 = db.Deleteable<Student>().Where(new List<Student>() { new Student() { Id = 1 } }).ExecuteCommand();

使用锁

var t2 = db.Deleteable<Student>().With(SqlWith.RowLock).ExecuteCommand();

根据主键删除

var t3 = db.Deleteable<Student>().In(1).ExecuteCommand();

根据主键批量删除

var t4 = db.Deleteable<Student>().In(new int[] { 1, 2 }).ExecuteCommand();

根据非主键批量删除4.9

var t4 = db.Deleteable<Student>().In(it=>it.SchoolId,new int[] { 1, 2 }).ExecuteCommand();

根据表达式删除

var t5 = db.Deleteable<Student>().Where(it => it.Id == 1).ExecuteCommand();//删除等于1的

//批量删除非主键

list<int> list=new list<int>(){1,3};

var t5 = db.Deleteable<Student>().Where(it => !list.Contains(it.Id) ).ExecuteCommand();

4.1.0.6 版本之后可以对上面的语法进行优化

db.Deleteable<Student>(1).ExecuteCommand();

db.Deleteable<Student>(it=>it.id==1).ExecuteCommand();

db.Deleteable<Student>(new int[]{1,2,3}).ExecuteCommand();

db.Deleteable<Student>(实体).ExecuteCommand();

更新

SqlSugar更新分为2大类写法，1种是传实体对象的方式 这种是以实体对象为核心进行更新，不传实体对象这种是以表达式为核心进行更新

//传实体对象写法（支持批量对象）

db.Updateable(updateObj)

//不传实体对象写法

db.Updateable<T>()

传对象的用法

根据实体更新（主键要有值，主键是更新条件）

var t1 = db.Updateable(updateObj).ExecuteCommand(); //这种方式会以主键为条件

4.2.3添加了WhereColumns 虽然XId不是主键但是 XId作为更新条件

var t1 = db.Updateable(updateObj).WhereColumns(it=>new{it.XId}).ExecuteCommand();//单列可以用 it=>it.XId

//需要注意 当WhereColumns和UpdateColumns一起用时，需要把wherecolumns中的列加到UpdateColumns中

var update = db.Updateable(updateObj).UpdateColumns(s => new { s.RowStatus,s.Id }).WhereColumns(it => new { it.Id });

只更新实体里面的Name列(主键要有值，主键是更新条件)

var t3 = db.Updateable(updateObj).UpdateColumns(it => new { it.Name }).ExecuteCommand();

更新 Name和 TestId 以外的所有列 (主键要有值，主键是更新条件)

var t4 = db.Updateable(updateObj)

.IgnoreColumns(it => new { it.Name, it.TestId }).ExecuteCommand();

更新NAME 以外的所有列

var t5 = db.Updateable(updateObj)

.IgnoreColumns(it => it=="name" ).ExecuteCommand(); //name列不更新

var t5 = db.Updateable(updateObj)

.IgnoreColumns(it => list.Contains(it)  ).ExecuteCommand(); //List中所有列不更新

使用锁

var t6 = db.Updateable(updateObj).With(SqlWith.UpdLock).ExecuteCommand();

批量更新(主键要有值，主键是更新条件)

List<Students> list=GetList();

var t7 = db.Updateable(list).ExecuteCommand();

实体更新，并且给Name重新赋值 ，其它列也会更新

var t8 = db.Updateable(updateObj)

.ReSetValue(it => it.Name == (it.Name + 1)).ExecuteCommand();

只更新Name并且 Name的值等于Name+1, 如果updateObj值为NULL一定要加WHERE才可以

//写法1

var t8 = db.Updateable(updateObj)

.UpdateColumns(it=>new {it.Name}).ReSetValue(it => it.Name == (it.Name + 1)).ExecuteCommand();

第一种updateable()有参数的，下面二种是没参数的注意下区别

更新实体，更新条件是根据表达式

var t9 = db.Updateable(updateObj).Where(it => it.Id == 1).ExecuteCommand();

是NULL的列不更新

db.Updateable(updateObj).IgnoreColumns(ignoreAllNullColumns:true).ExecuteCommand();

4.6.4.8 版本支持了不需要泛型的字典

//如果initKey.Systemtable方是写法

var dt = new Dictionary<string,object>();

dt.Add("id", 1);

dt.Add("name", "1");

var t66 = db.Updateable(dt).AS("student").ExecuteCommand();

//UPDATE STUDENT  SET  NAME=@name  WHERE ID=@ID

//如果initkey.Attribute方式是拿不出主键信息的需要写成这样

var dt = new Dictionary<string,object>();

dt.Add("id", 1);

dt.Add("name", "1");

var t66 = db.Updateable(dt).AS("student").WhereColumns("id").With(SqlWith.UpdLock).ExecuteCommand()

//没有WhereColumns(string)去下载最新的

//也支持List<Dictionary<string,object>>

4.2.2 更新 匿名对象和字典的支持

 var t13 = db.Updateable<Student>(new { Name = "a", id=1 }).ExecuteCommand();

 //UPDATE [STudent]  SET [Name]='a' WHERE [Id]=1

 var t14 = db.Updateable<Student>(new Dictionary<string, object>() { { "id", 1 }, { "name", "a" } }).ExecuteCommand();

 //UPDATE [STudent]  SET [Name]='a' WHERE [Id]=1

不传对象的用法

根据表达式中的列更新   ，只更新 Name和CreateTime 条件是id=11，比较常用

//正确写法

 var t10 = db.Updateable<Student>()

.UpdateColumns(it => new Student() { Name = "a", CreateTime = DateTime.Now })

.Where(it => it.Id == 11).ExecuteCommand();

//错误写法

var st=new Student() { Name = "a", CreateTime = DateTime.Now };

var t10 = db.Updateable<Student>()

.UpdateColumns(it => st)

.Where(it => it.Id == 11).ExecuteCommand();

别名表

db.Updateable<School>().AS("Student")

.UpdateColumns(it => new School() { Name = "jack" })

.Where(it => it.Id == 1).ExecuteCommand();

//Update Student set Name='jack' Where Id=1

4.6.0.7 联表更新

var t17 = db.Updateable<Student>().UpdateColumns(it =>

       new Student(){

        SchoolId = SqlFunc.Subqueryable<School>().Where(s => s.Id == it.SchoolId).Select(s => s.Id),

        Name = "newname"

       }).Where(it => it.Id == 1).ExecuteCommand();

UPDATE [STudent]  SET

            [SchoolId] = (SELECT TOP 1 [Id] FROM [School] WHERE ( [Id] =[STudent].[SchoolId] )) ,

            [Name] = @Const0   WHERE ( [ID] = @Id1 )

只更新Name并且 Name的值等于Name+1

//写法1

var t8 = db.Updateable<Student>().UpdateColumns(it => new Student() { Name = it.Name+1}).Where(it => it.Id == 11).ExecuteCommand();

//写法2 (注意：4.5.9.8以上版本支持) 如果只有一列可以简化成这种写法

var t8= db.Updateable<Student>().UpdateColumns(it => it.Name == it.Name+1).Where(it => it.Id == 11).ExecuteCommand();

技巧功能

//根据不同条件执行更新不同的列

var t3 = db.Updateable(updateObj)

                .UpdateColumnsIF(caseValue=="1",it => new { it.Name })

                .UpdateColumnsIF(caseValue=="2", it => new { it.Name,it.CreateTime })

                .ExecuteCommand();

更新对数据的 版本控制

例如我想验证我表单传过来的数据在数据库是否是最新的版本，不是最新版本抛出提示，

参考这个DEMO

https://github.com/sunkaixuan/SqlSugar/blob/dev/Src/Asp.Net/SqlServerTest/Demos/F_VersionValidation.cs