用SQL合并两个表的问题
我有下面两张表Table1和Table2,想用SQL把他们合并成Table3的样子，请问怎么实现？其中Table3中的NO3字段=NO1-NO2
Table1 Table2 Table3
Part Date NO1 Part Date NO2 Part Date NO1 NO2 NO3
part1 2005 3 part1 2005 3 part1 2005 3 3 0
part2 2005 2 part2 2006 1 part2 2005 2 2
part3 2005 1 part4 2005 1 part2 2006 1 -1
part3 2005 1 1
part4 2005 1 -1
[解决办法]
select t1.part,t1.date,t1.no1,t2,no2,t1.no1-t2.no2 as no3 from table1 t1
inner join table2 t2 on t1.part=t2.part and t1.date=t2.date
