SqlServer中字符型转换为数字型出项的问题

SqlServer中字符型转换为数字型出项的问题

select  @rno=rno from deleted;
convert(numeric,@rno);
@rno=@rno/1000;

消息 156，级别 15，状态 1，过程 t2，第 11 行
关键字 'convert' 附近有语法错误。

---

select  @rno=rno from deleted;
set @rno = cast(@rno as numeric)

---

SQL code:
select @rno=rno from deleted;
SET @rno=convert(numeric,@rno);
SET @rno=@rno/1000;

---

SQL code:
select @rno=rno from deleted;
SET @rno=convert(numeric(18,5),@rno);
SET @rno=@rno/1000;

设计一下精度

---

引用

select  @rno=rno from deleted;
set @rno = cast(@rno as numeric)

哦！原来如此！这样才行！
可是这样转过之后又出现个问题

消息 102，级别 15，状态 1，过程 t2，第 12 行
'@rno' 附近有语法错误。
转换成数值型之后为什么不能进行数学运算呢？？

---

SQL code:
declare @rno varchar(20)
set @rno=convert(numeric(18,2),@rno);
set @rno=@rno/1000;
select @rno=rno from deleted;

---

SQL code

---

Code highlighting produced by