update语句问题
update fljh set LEFT(ltrim(fld_wl_bh),2) = upper(LEFT(ltrim(fld_wl_bh),2))
请帮忙看下此语句有何问题？
------解决方案--------------------

只能这样写，不可以直接搞



update fljh 

set fld_wl_bh=REPLACE(fld_wl_bh,LEFT(ltrim(fld_wl_bh),2),upper(LEFT(ltrim(fld_wl_bh),2)))

------解决方案--------------------
糾正如下：
update fljh set fld_wl_bh = ltrim(fld_wl_bh)
update fljh set fld_wl_bh = stuff(fld_wl_bh,1,2,upper(LEFT(fld_wl_bh,2)))
------解决方案--------------------

update fljh 

 set fld_wl_bh=upper(LEFT(ltrim(fld_wl_bh),2))

 where LEFT(ltrim(fld_wl_bh),2)=upper(LEFT(ltrim(fld_wl_bh),2))

------解决方案--------------------

update fljh SET fld_wl_bh=upper(LEFT(ltrim(fld_wl_bh),2))+LTRIM(RIGHT(fld_wl_bh,LEN(fld_wl_bh)-2))

------解决方案--------------------
update fljh set LEFT(ltrim(fld_wl_bh),2) = upper(LEFT(ltrim(fld_wl_bh),2))

set 后面的LEFT(ltrim(fld_wl_bh),2) 只是函数转化后的虚拟列，也就说是返回值，并不是真实存在的列。