Eliminación de prueba de SqlServer y cálculo de fecha

eliminar declaración

-- 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 ;

calculo de fecha

Tres días seleccione * de T_news donde fechado(día,añadirhora,obtenerfecha())<= 2 y fechado(día,añadirhora,obtenerfecha())>= 0 Una semana seleccione * de T_noticias DONDE (DATEPART(sem, añadirhora) = DATEPART
( wk, GETDATE())) AND (DATEPART(yy, addtime) = DATEPART(yy, GETDATE()))
Nota: fechada no se puede usar en este momento, la diferencia es 7, porque fechada solo representa el número de intervalo
en enero 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()) y DATEPART(aa, addtime) = DATEPART(aa, GETDATE())
esta semana: seleccione * de la tabla donde fechadoiff(semana,C_CALLTIME,getdate())=0 --C_CALLTIME es el campo de fecha
Este mes: seleccione * de la tabla donde fechado(Mes,C_CALLTIME,getdate())=0 --C_CALLTIME es el campo de fecha
Esta temporada: seleccione * de la tabla donde fechadoiff(qq,C_CALLTIME,getdate())=0
1-6 en la primera mitad, 7-12 en la segunda mitad: seleccione * de la tabla donde fechapart(mm,C_CALLTIME)/7 = partefecha(mm, obtenerfecha())/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