有下面的表:
WL   Time    number    number1    number2
A      11        0             0                5
B       11       0             0                6
A       12       4             0                9
B        12      0             5                1
A        13      5             0                14
A         13      0            6                8
B        13      3             0                4头两行是基础,后面的number2都为0,怎么写update语句,然后下面的每一行都按照WL不同,最后一个相同WL的number2+number-number1得到本行的number2如第三行5+4-0=9,第四行6-5=1,第五行:9+5=14。急求。谢谢大家了