--表名： [dbo].[tee]
id    int    Unchecked
FName    nvarchar(50)    Unchecked
FSalary    decimal(18, 0)    Unchecked
--表名： [dbo].[TRecordTee]
id    int    Unchecked
RecordString    nvarchar(100)    Unchecked

-- 创建一个触发器
create  trigger recordTee 
    on dbo.tee
    after update ,insert
as
begin
    declare @Name nvarchar(50) ;
    declare @Salary decimal(18,0)
    select @Name=i.Fname,@Salary=i.FSalary from [inserted] as i; -- [inserted]是不能变的，表示主表。
    --insert 
    insert into dbo.TRecordTee (RecordString) values('Time:'+convert(nvarchar(20),getDate(),101)+'Name:'+convert(nvarchar(10),@Name)+' salary:'+convert(nvarchar(10),@Salary));
    --select * from dbo.TRecordTee;
end

insert into  dbo.tee(FName,Fsalary)values('mmm',5000);
go
select *from dbo.tee;

   --现在 国家规定：
   --要求工资一定要 大于 1500元/月；
  如何 修改 触发器[recordTee] 使得插入，or 修改的表[dbo.tee]的工资 Fsalary<=1500时， 就不允许输入？ 

-- 创建一个触发器
create  trigger recordTee 
    on dbo.tee
    after update ,insert
as
begin
    declare @Name nvarchar(50) ;
    declare @Salary decimal(18,0)
    select @Name=i.Fname,@Salary=i.FSalary from [inserted] as i; -- [inserted]是不能变的，表示主表。
    --insert 
    if @Salary>1500
    begin
    insert into dbo.TRecordTee (RecordString) values('Time:'+convert(nvarchar(20),getDate(),101)+'Name:'+convert(nvarchar(10),@Name)+' salary:'+convert(nvarchar(10),@Salary));
    --select * from dbo.TRecordTee;
    end
    
end

------解决方案--------------------
那用 INSTEAD OF  替换 AFTER


------解决方案--------------------
SQL code

-- 创建一个触发器
create  trigger recordTee 
    on dbo.tee
     INSTEAD OF update ,insert
as
begin
    declare @Name nvarchar(50) ;
    declare @Salary decimal(18,0)
    select @Name=i.Fname,@Salary=i.FSalary from [inserted] as i; -- [inserted]是不能变的，表示主表。
    --insert 
    if @Salary>1500
    begin
    insert into  dbo.tee(FName,Fsalary)values('mmm',5000);
    insert into dbo.TRecordTee (RecordString) values('Time:'+convert(nvarchar(20),getDate(),101)+'Name:'+convert(nvarchar(10),@Name)+' salary:'+convert(nvarchar(10),@Salary));
    --select * from dbo.TRecordTee;
    end
    
end

------解决方案--------------------
SQL code

create  trigger recordTee 
    on dbo.tee
    for update ,insert
as
begin
    declare @Name nvarchar(50) ;
    declare @Salary decimal(18,0)
    select @Name=i.Fname,@Salary=i.FSalary from [inserted] as i; -- [inserted]是不能变的，表示主表。
    if @salary>=1500
    begin
    insert into dbo.TRecordTee (RecordString) 
values('Time:'+convert(nvarchar(20),getDate(),101)+'Name:'+convert(nvarchar(10),@Name)+' salary:'+convert(nvarchar(10),@Salary));
    end
  else 
begin
print '工资不能少于1500元'
end
    --select * from dbo.TRecordTee;
end

------解决方案--------------------
触发器比较费劲，用约束简单

SQL code

create table [dbo].[tee](
id    int,
FName    nvarchar(50),
FSalary    decimal(18, 0))


ALTER TABLE [dbo].[tee]
ADD CONSTRAINT chk_tee CHECK (FSalary>1500)


insert into [tee] select 1,'aaaa',1000

------------------
消息 547，级别 16，状态 0，第 1 行
INSERT 语句与 CHECK 约束"chk_tee"