这个功能我是琢磨了好久，本来我的sqlserver方面的知识深入了解的就不多，关键的难点是用变量代替字段名，然后获取字段在表中存的值，再赋给另外一个变量，我之所以这么做，因为后面好几处要用到这个字段的名称，我才用变量代替，便于修改，可就是实现花费了很长时间，网上这么方面的资料又少，可终究还是找到了解决方案，希望大家以后遇到同样的问题不至于头大，把具体的实现分享给大家
create trigger [dbo].[trg_new_course]
on [dbo].[course]
for insert,delete,update
as
begin
declare @tabname varchar(50),
@pkname varchar(20),
@pkvalue varchar(20),
@opttype int,
@optip varchar(20),
@optsql varchar(200),
@xmlstr nvarchar(500);
declare @optinfo nvarchar(500),
@id_i int,
@id_d int;
declare @min_id int, –最小的字段号
@total int, –记录总数
@row_count int, –循环变量
@temp_name varchar(100), –临时字段名
@temp_pre_name varchar(100), –带字段类型前缀的变量
@temp_type varchar(100), –临时字段类型
@temp_value varchar(100), –临时字段值
@xmlnode_value varchar(100), –xml的节点值
@sql_name varchar(100), –sql操作相关的字段
@sql_value varchar(100), –sql操作相关的字段值
@sql nvarchar(200), –存储动态sql
@pk_pre_name varchar(20) –带类型前缀的关键字段名
set @sql_name = ”;
set @sql_value = ”;
set @row_count = 1;
set @pkname = ‘id’; –关键字名称
set @tabname = ‘course’; –操作的表名
set @optinfo = ”;
select @id_i=id from inserted;
select @id_d=id from deleted;
select @temp_type = data_type from information_schema.columns where table_name = @tabname and column_name = @pkname;
if (@temp_type = ‘int’)
begin
set @pk_pre_name = ‘i’ + @pkname
end
else if(@temp_type = ‘float’)
begin
set @pk_pre_name = ‘f’ + @pkname
end
else if(@temp_type = ‘decimal’)
begin
set @pk_pre_name = ‘d’ + @pkname
end
else if(@temp_type = ‘datetime’)
begin
set @pk_pre_name = ‘da’ + @pkname
end
else
begin
set @pk_pre_name = ‘c’ + @pkname
end
if @id_i is null and @id_d is not null –删除操作
begin
set @pkvalue = @id_d;
set @opttype = 1;
–若变量的类型不是字符串型
set @pkvalue = convert(varchar(200),@pkvalue);
–生成执行删除操作的sql语句
set @optsql = ‘delete from ‘ + @tabname + ‘ where ‘ + @pkname + ‘=’ + @pkvalue;
–生成删除操作字段信息的xml表示
set @optinfo = @optinfo + ‘<‘ + @pkname +’>’;
set @optinfo = @optinfo + @pkvalue;
set @optinfo = @optinfo + ”;
end
else
begin
set @pkvalue = @id_i;
select * into temps from inserted;–这句必须写动态sql中时找不到inerted这个逻辑表的
select @min_id = max(ordinal_position) from information_schema.columns where table_name = @tabname;
select @total = count(1) from information_schema.columns where table_name = @tabname;
while(@row_count <= @total)
begin
select @temp_name = column_name,@temp_type = data_type from information_schema.columns where table_name = @tabname and ordinal_position = @min_id;
if(@temp_type = ‘int’)
begin
declare @temp_in int;
set @sql = ‘select @temp_in = ‘ + @temp_name + ‘ from temps;’;
exec sp_executesql @sql, n’@temp_in int output’, @temp_in output;
set @xmlnode_value = convert(varchar(100),@temp_in);
set @temp_value = @xmlnode_value;
set @temp_pre_name = ‘i’ + @temp_name;
end
else if(@temp_type = ‘float’)
begin
declare @temp_inf float;
set @sql = ‘select @temp_inf = ‘ + @temp_name + ‘ from temps;’;
exec sp_executesql @sql, n’@temp_inf float output’, @temp_inf output;
set @xmlnode_value = convert(varchar(100),@temp_inf);
set @temp_value = @xmlnode_value;
set @temp_pre_name = ‘f’ + @temp_name;
end
else if(@temp_type = ‘decimal’)
begin
declare @temp_ind float;
set @sql = ‘select @temp_ind = ‘ + @temp_name + ‘ from temps;’;
exec sp_executesql @sql, n’@temp_ind decimal(18,0) output’, @temp_ind output;
set @xmlnode_value = convert(varchar(100),@temp_ind);
set @temp_value = @xmlnode_value;
set @temp_pre_name = ‘d’ + @temp_name;
end
else
begin
declare @temp_inc varchar(200);
set @sql = ‘select @temp_inc = ‘ + @temp_name + ‘ from temps;’;
exec sp_executesql @sql, n’@temp_inc varchar(200) output’, @temp_inc output;
set @xmlnode_value = convert(varchar(100),@temp_inc);
set @temp_value = ”” + @xmlnode_value + ””;
set @temp_pre_name = ‘c’ + @temp_name;
end
–生成插入/修改操作相关数据信息的xml表示
set @optinfo = @optinfo + ‘<‘ + @temp_pre_name + ‘>’;
set @optinfo = @optinfo + @xmlnode_value;
set @optinfo = @optinfo + ”;
if @id_i is not null and @id_d is null — 插入操作
begin
–生成插入操作执行的sql语句
if(@temp_name <> @pkname)
begin
set @sql_name = @sql_name + ‘,’ + @temp_name;
set @sql_value = @sql_value + ‘,’ + @temp_value;
end
end
else if @id_i is not null and @id_d is not null –更新操作
begin
–生成修改操作执行的sql语句
if(@temp_name <> @pkname)
begin
set @sql_name = @sql_name + ‘,’ + @temp_name + ‘=’ + @temp_value;
end
end
select @min_id = ordinal_position from information_schema.columns where table_name = ‘course’ and ordinal_position < @min_id;
set @row_count = @row_count + 1;
end
if @id_i is not null and @id_d is null — 插入操作
begin
–生成执行插入操作的sql语句
set @opttype = 0;
set @optsql = ‘insert into ‘ + @tabname + ‘(‘ + substring(@sql_name,2,len(@sql_name)) + ‘)’ + ‘ values(‘ + substring(@sql_value,2,len(@sql_value)) +’)’;
end
else if @id_i is not null and @id_d is not null –更新操作
begin
–生成执行修改操作的sql语句
set @opttype = 3;
set @optsql = ‘update ‘ + @tabname + ‘ set ‘ + substring(@sql_name,2,len(@sql_name)) + ‘ where ‘ + @pkname + ‘=’ + @pkvalue;
end
drop table temps;
end
set @xmlstr = ”;
set @xmlstr = @xmlstr + ”;
set @xmlstr = @xmlstr + ” + convert(varchar(3),@opttype) + ”;
set @xmlstr = @xmlstr + ” + @tabname + ”;
set @xmlstr = @xmlstr + ” + @pk_pre_name + ”;
set @xmlstr = @xmlstr + ”;
set @xmlstr = @xmlstr + ”;
set @xmlstr = @xmlstr + @optinfo;
set @xmlstr = @xmlstr + ”;
set @xmlstr = @xmlstr + ”;
select @optip=client_net_address from sys.dm_exec_connections where session_id=@@spid;
if(@pkvalue is null)
begin
set @pkvalue = -1;
end
insert into optlog values(@tabname,@pkname,@pkvalue,@opttype,@optip,getdate(),@optsql,@xmlstr);
print ‘操作执行成功’;
end
红色标注的部分我认识是实现的难点，就是用到了sqlserver的存储过程sp_executesql，具体的用法网上有的可以查下，这只是我的一家之言，或许大家还有很好的实现，欢迎大家提意见啊!