SqlSugar查询操作
系列文章目录
第1章 SqlSugar-表到实体、实体到表及库表操作
第2章 SqlSugar增删改操作
第3章 SqlSugar查询操作
第4章 SqlSugar导航查询、反向导航查询、导航插入、导航更新
文章目录
- 系列文章目录
- 一、简单查询
-
- 1.1、查询集合
- 1.2、查询总数
- 1.3、条件查询
- 1.4、动态OR查询
- 1.5、模糊查询
- 1.6、主键查询
- 1.7、查第一条
- 1.8、查前几条
- 1.9、查询是否有记录
- 二、连接查询
-
- 2.1、准备
- 2.2、左连接
- 2.3、右连接
- 2.4、内连接
- 三、复杂查询
-
- 3.1、分组聚合
- 3.2、去重
- 3.3、分页查询
一、简单查询
1.1、查询集合
//select * from StudentInfo
List<StudentInfo> list = db.Queryable<StudentInfo>().ToList();
1.2、查询总数
int count = db.Queryable<StudentInfo>().Count();
1.3、条件查询
List<StudentInfo> studentList;
//按条件查询//select * from StudentInfo where id=1
studentList = db.Queryable<StudentInfo>()
.Where(it => it.Id == 1).ToList();
多条件查询
{
studentList = db.Queryable<StudentInfo>()
.Where(it => it.Id > 10 && it.Name == "名称_11").ToList();
//select * from StudentInfo where id>10 and name='a'
studentList = db.Queryable<StudentInfo>()
.Where(it => it.Id > 10)
.Where(it => it.Name == "名称_11").ToList();
}
多个字段 条件拼接查询
{
List<StudentInfo> OrderList = new List<StudentInfo>()
{
new StudentInfo{ Id = 1,Name="名称_1"},
new StudentInfo{ Id = 2,Name="名称_2"},
new StudentInfo{ Id = 3,Name="名称_3"}
};
Expressionable<StudentInfo> exp = new Expressionable<StudentInfo>();
foreach (var item in OrderList)
{
exp.Or(it => it.Id == item.Id && it.Name == item.Name);
}
//使用构造好的表达式
var studentlist = db.Queryable<StudentInfo>().Where(exp.ToExpression()).ToList();
}
1.4、动态OR查询
{
Expressionable<StudentInfo> exp = Expressionable.Create<StudentInfo>();
string name = "名称_11";
//.OrIf 是条件成立才会拼接OR
exp.OrIF(!string.IsNullOrWhiteSpace(name), it => it.Name.Contains(name));
//拼接OR
exp.Or(it => it.Name.Contains("名称_"));
studentList = db.Queryable<StudentInfo>()
.Where(exp.ToExpression()).ToList();
}
1.5、模糊查询
{
studentList = db.Queryable<StudentInfo>()
.Where(it => it.Name.Contains("名称_")).ToList();
//select * from StudentInfo where name like %名称_%
}
1.6、主键查询
//根据主键查询
{
/*单主键查询*/
//通过主键查询 SingleById
var it=db.Queryable<StudentInfo>().InSingle(2);
//根据ID查询
//select * from StudentInfo where id=2
it=db.Queryable<StudentInfo>().Single(it => it.Id == 2);
/*多主键查询*/
var getAll = db.Queryable<StudentInfo>()
.WhereClassByPrimaryKey(new StudentInfo() { Id = 123 })
.ToList(); //单个实体
getAll = db.Queryable<StudentInfo>()
.WhereClassByPrimaryKey(new List<StudentInfo>()
{
new StudentInfo() { Id = 123 },
new StudentInfo() { Id = 234 },
new StudentInfo() { Id = 345 }
}).ToList(); //支持集合
}
1.7、查第一条
//没有返回Null
StudentInfo student = db.Queryable<StudentInfo>().First(it => it.Id == 1);
1.8、查前几条
前10条：
List<StudentInfo> studetntlist = db.Queryable<StudentInfo>().Take(10).ToList();
1.9、查询是否有记录
isExists = db.Queryable<StudentInfo>().Any(it => it.Id > 11);
二、连接查询
2.1、准备
ConnectionConfig connectionConfig = new ConnectionConfig()
{
ConnectionString = CustomConnectionConfig.ConnectionString001,
IsAutoCloseConnection = true,
DbType = DbType.SqlServer
};
using (SqlSugarClient db = new SqlSugarClient(connectionConfig))
{
db.CodeFirst.InitTables<Company>();
db.CodeFirst.InitTables<User>();
db.CodeFirst.InitTables<UserScore>();
db.Deleteable<UserScore>().ExecuteCommand();
db.Deleteable<Company>().ExecuteCommand();
db.Deleteable<User>().ExecuteCommand();
List<Company> companyList = new List<Company>();
for (int i = 0; i < 3; i++)
{
companyList.Add(new Company()
{
CreateTime = DateTime.Now,
Id = i + 1,
CompanyName = $"供热_{i + 1}"
});
}
db.Insertable<Company>(companyList).ExecuteCommand();
List<User> userList = new List<User>();
List<UserScore> userScoreList = new List<UserScore>();
for (int i = 0; i < 10; i++)
{
userList.Add(new User()
{
CreateTime = DateTime.Now,
Id = i + 1,
UserName = $"用户_{i + 1}",
CompanyId = companyList[0].Id
});
userScoreList.Add(new UserScore()
{
UserId = i + 1,
Subject = "考勤",
Achievement = 90,
CreateTime = DateTime.Now
});
userScoreList.Add(new UserScore()
{
UserId = i + 1,
Subject = "绩效",
Achievement = 90,
CreateTime = DateTime.Now
});
userScoreList.Add(new UserScore()
{
UserId = i + 1,
Subject = "项目奖金",
Achievement = 89,
CreateTime = DateTime.Now
});
}
db.Insertable<User>(userList).ExecuteCommand();
db.Insertable<UserScore>(userScoreList).ExecuteCommand();
//配置生成sql语句
{
db.Aop.OnLogExecuting = (s, p) =>
{
Console.WriteLine("----------------------------");
Console.WriteLine($"Sql语句:{s}");
};
}
2.2、左连接
var query1 = db.Queryable<Company>()
.LeftJoin<User>((c, u) => c.Id == u.CompanyId)
.LeftJoin<UserScore>((c, u, us) => u.Id == us.UserId)
.Where(c => c.Id == 1)
.Select((c, u, us) => new
{
CompanyId = c.Id,
CompanyName = c.CompanyName,
UserNae = u.UserName,
Subject = us.Subject,
ScoreCoutn = us.Achievement
})
.ToList();
等价sql：
SELECT [c].[Id] AS [CompanyId] , [c].[CompanyName] AS [CompanyName] , [u].[UserName] AS [UserNae] ,
[us].[Subject] AS [Subject] , [us].[Achievement] AS [ScoreCoutn]
FROM [Company] c
Left JOIN [User] u ON ( [c].[Id] = [u].[CompanyId] )
Left JOIN [UserScore] us ON ( [u].[Id] = [us].[UserId] )
WHERE ( [c].[Id] = @Id0 )
2.3、右连接
var query1 = db.Queryable<Company>()
.RightJoin<User>((c, u) => c.Id == u.CompanyId)
.RightJoin<UserScore>((c, u, us) => u.Id == us.UserId)
.Where(c => c.Id == 1)
.Select((c, u, us) => new
{
CompanyId = c.Id,
CompanyName = c.CompanyName,
UserNae = u.UserName,
Subject = us.Subject,
ScoreCoutn = us.Achievement
})
.ToList();
等价SQL：
SELECT [c].[Id] AS [CompanyId] , [c].[CompanyName] AS [CompanyName] ,
[u].[UserName] AS [UserNae] , [us].[Subject] AS [Subject] , [us].[Achievement] AS [ScoreCoutn]
FROM [Company] c
Right JOIN [User] u ON ( [c].[Id] = [u].[CompanyId] )
Right JOIN [UserScore] us ON ( [u].[Id] = [us].[UserId] )
WHERE ( [c].[Id] = @Id0 )
2.4、内连接
var query1 = db.Queryable<Company>()
.InnerJoin<User>((c, u) => c.Id == u.CompanyId)
.InnerJoin<UserScore>((c, u, us) => u.Id == us.UserId)
.Where(c => c.Id == 1)
.Select((c, u, us) => new
{
CompanyId = c.Id,
CompanyName = c.CompanyName,
UserNae = u.UserName,
Subject = us.Subject,
ScoreCoutn = us.Achievement
})
.ToList();
SELECT [c].[Id] AS [CompanyId] , [c].[CompanyName] AS [CompanyName] ,
[u].[UserName] AS [UserNae] , [us].[Subject] AS [Subject] , [us].[Achievement] AS [ScoreCoutn]
FROM [Company] c
Inner JOIN [User] u ON ( [c].[Id] = [u].[CompanyId] )
Inner JOIN [UserScore] us ON ( [u].[Id] = [us].[UserId] )
WHERE ( [c].[Id] = @Id0 )
三、复杂查询
3.1、分组聚合
{
var list = db.Queryable<Student>()
.GroupBy(it => new { it.Id, it.Name })
.Having(it => SqlFunc.AggregateAvg(it.Id) > 0)
.Select(it => new
{
idAvg = SqlFunc.AggregateAvg(it.Id),
count = SqlFunc.AggregateCount(it.Id),
name = it.Name
})
.ToList();
}
等价sql：
SELECT AVG([Id]) AS [idAvg] , COUNT([Id]) AS [count] , [StudentName] AS [name]
FROM [dbstudent] GROUP BY [Id],[StudentName] HAVING (AVG([Id]) > @Const0 )
3.2、去重
var list = db.Queryable<Student>()
.Distinct()
.Select(it => new { it.Name }).ToList();
3.3、分页查询
单表分页
var page = db.Queryable<Student>()
.ToPageList(pagenumber, pageSize, ref totalCount);
SELECT * FROM
(SELECT [Id],[SchoolId],[StudentName],[CreateTime],ROW_NUMBER()
OVER( ORDER BY GetDate() ) AS RowIndex FROM [dbstudent] ) T
WHERE RowIndex BETWEEN 3 AND 4
或：
var page1 = db.Queryable<Student>()
.ToOffsetPage(pagenumber, pageSize, ref totalCount);
SELECT [Id],[SchoolId],[StudentName],[CreateTime]
FROM [dbstudent]
ORDER BY GETDATE()
OFFSET 2 ROWS FETCH NEXT 2 ROWS ONLY
多表分页
如果SqlServer不想有Rownumber可以用 ToOffsetPage 较新版本支持
{
int pagenumber = 1; // pagenumber是从1开始的不是从零开始的
int pageSize = 20;
int totalCount = 0;
var list = db.Queryable<Company>()
.LeftJoin<User>((c, u) => c.Id == u.CompanyId)
.Select((c, u) => new
{
Id = c.Id,
cName = c.CompanyName,
uId = u.Id,
uName = u.UserName
}).ToOffsetPage(pagenumber, pageSize, ref totalCount);
}
SELECT COUNT(1)
FROM
(SELECT [c].[Id] AS [Id] , [c].[CompanyName] AS [cName] , [u].[Id] AS [uId] , [u].[UserName] AS [uName]
FROM [Company] c Left JOIN [User] u ON ( [c].[Id] = [u].[CompanyId] ) )
CountTable
----------------------------
SELECT [c].[Id] AS [Id] , [c].[CompanyName] AS [cName] , [u].[Id] AS [uId] , [u].[UserName] AS [uName]
FROM [Company] c
Left JOIN [User] u ON ( [c].[Id] = [u].[CompanyId] )
ORDER BY GETDATE() OFFSET 0 ROWS FETCH NEXT 20 ROWS ONLY