求一条一句，先谢谢了
表1
bano,eqno,qty
ba,ea,100
ba,ed,100
bc,ea,50
be,ef,50
----------------------------
表2
bano,eqno,jhs,wcs
ba,ea,24,0
ba,ea,24,0
ba,ea,24,0
ba,ea,24,0
ba,ea,24,0
ba,ea,14,0
ba,ed,30,0
ba,ed,20,0
bc,ea,12,0
bc,ea,12,0
bc,ea,12,0
bc,ea,12,0
bc,ea,2,0
be,ef,24,0
be,ef,24,0
be,ef,24,0
be,ef,24,0
----------------------------
bano,eqno为varchar类型，jhs,wcs,qty为int类型
======================
需要下面结果
表2
bano,eqno,jhs,wcs
ba,ea,24,24
ba,ea,24,24
ba,ea,24,24
ba,ea,24,24
ba,ea,24,4
ba,ea,14,0
ba,ed,30,30
ba,ed,20,20
bc,ea,12,12
bc,ea,12,12
bc,ea,12,12
bc,ea,12,12
bc,ea,2,2
be,ef,24,24
be,ef,24,24
be,ef,24,2
be,ef,24,0
意思是说
当表2里的bano,eqno字段和表1相同 and 表1的qty > 0 时候修改表2中wcs字段(wcs字段数值不能大于表1的qty字段，同时也不能大于表2的jhs),修改表2wcs字段后，要将表1的qty-wcs
[解决办法]
