SqlServer test delete and date calculation

delete statement

-- 创建t1表，并插入3条数据
CREATE TABLE [dbo].[t1] ([id] [INT] NOT NULL, [name] [NCHAR](10) NULL) ON [PRIMARY];
GO
INSERT INTO dbo.t1(id, name)
VALUES(1, -- id - int
N'lisi' -- name - nchar(10)
    );

INSERT INTO dbo.t1(id, name)
VALUES(2, -- id - int
N'zhangsan' -- name - nchar(10)
    );


INSERT INTO dbo.t1(id, name)
VALUES(3, -- id - int
N'aben' -- name - nchar(10)
    );

-- 创建t2表，并插入2条数据
CREATE TABLE [dbo].[t2] ([id] [INT] NOT NULL, [name] [NCHAR](10) NULL) ON [PRIMARY];
GO
INSERT INTO dbo.t2(id, name)
VALUES(1, -- id - int
N'lisi' -- name - nchar(10)
    );

INSERT INTO dbo.t2(id, name)
VALUES(2, -- id - int
N'zhangsan' -- name - nchar(10)
    );



SELECT * FROM dbo.t1;

SELECT * FROM dbo.t2;

SELECT b.* FROM t1 AS a INNER JOIN t2 AS b ON a.id=b.id;


-- 删除内关联t1表后的2条记录
DELETE t1 FROM t1 AS a INNER JOIN t2 AS b ON a.id=b.id;

-- 删除内关联t2表后的2条记录
DELETE t2 FROM t1 AS a INNER JOIN t2 AS b ON a.id=b.id;



SELECT b.* FROM t1 AS a LEFT JOIN t2 AS b ON a.id=b.id;

-- 删除左外关联后的t1表3条记录
DELETE t1 FROM t1 AS a LEFT JOIN t2 AS b ON a.id=b.id;

-- 删除左外关联后的t2表2条记录
DELETE t2 FROM t1 AS a LEFT JOIN t2 AS b ON a.id=b.id;


-- 关联删除t1
delete from t1  from t2  inner join t1  on t1.id=t2.id ;

date calculation

Three days select * from T_news where datediff(day,addtime,getdate())<= 2 and datediff(day,addtime,getdate())>= 0 One week select * from T_news WHERE (DATEPART(wk, addtime) = DATEPART
( wk, GETDATE())) AND (DATEPART(yy, addtime) = DATEPART(yy, GETDATE()))
Note: datediff cannot be used at this time, the difference is 7, because datediff only represents the interval number
in January select * from T_news WHERE (DATEPART(yy, addtime) = DATEPART(yy, GETDATE())) AND (DATEPART(mm, addtime) = DATEPART(mm, GETDATE())) Q1 select *
from T_news where DATEPART(qq, addtime) = DATEPART(qq, GETDATE()) and DATEPART(yy, addtime) = DATEPART(yy, GETDATE())
this week: select * from table where datediff(week,C_CALLTIME,getdate())=0 --C_CALLTIME is the date field
This month: select * from table where datediff(Month,C_CALLTIME,getdate())=0 --C_CALLTIME is the date field
This season: select * from table where datediff(qq,C_CALLTIME,getdate())=0
1-6 in the first half, 7-12 in the second half: select * from table where datepart(mm,C_CALLTIME)/7 = datepart(mm, getdate())/7

--sql得到当前系统时间得 日期部分

CONVERT(varchar(10),getDate(),120)

--昨天

select convert(varchar(10),getdate() - 1,120)

--明天

select convert(varchar(10),getdate() + 1,120)

--最近七天

select * from tb where 时间字段 >= convert(varchar(10),getdate() - 7,120)

--随后七天

select * from tb where 时间字段 <= convert(varchar(10),getdate() + 7,120) and 时间字段 >= --时间字段

--上月

select * from tb where month(时间字段) = month(getdate()) - 1

--本月

select * from tb where month(时间字段) = month(getdate())

--下月

select * from tb where month(时间字段) = month(getdate()) + 1

--昨天

Select * From TableName Where DateDiff(dd, DateTimCol, GetDate()) = 1

--明天

Select * From TableName Where DateDiff(dd, GetDate(), DateTimCol) = 1

--最近七天

Select * From TableName Where DateDiff(dd, DateTimCol, GetDate()) <= 7

--随后七天

Select * From TableName Where DateDiff(dd, GetDate(), DateTimCol) <= 7

--上周

Select * From TableName Where DateDiff(wk, DateTimCol, GetDate()) = 1

--本周

Select * From TableName Where DateDiff(wk, DateTimCol, GetDate()) = 0

--下周

Select * From TableName Where DateDiff(wk, GetDate(), DateTimCol ) = 1

--上月

Select * From TableName Where DateDiff(mm, DateTimCol, GetDate()) = 1

--本月

Select * From TableName Where DateDiff(mm, DateTimCol, GetDate()) = 0

--下月

Select * From TableName Where DateDiff(mm, GetDate(), DateTimCol ) = 1

--------------------------------------------------------

--本周

select * from tb where datediff(week , 时间字段 ,getdate()) = 0

--上周

select * from tb where datediff(week , 时间字段 ,getdate()) = 1

--下周

select * from tb where datediff(week , 时间字段 ,getdate()) = -1