摘要:
Store_Info表: store_name sales date A 500 01-01-2000 B 200 02-01-2000 A 1500 02-10-2000 D 1000 03-08-2000 Sales表: sales date 200 02-01-2000 1000 03-08- 阅读全文
摘要:
Store_Info表: store_name sales date A 500 01-01-2000 B 200 02-01-2000 A 1500 02-10-2000 D 1000 03-08-2000 AVG(平均) : SELECT AVG(sales) FROM Story_Info W 阅读全文
摘要:
为了更好的学习SQL语句,我们先来设定几张表格: Store_Info表: store_name sales Date A 500 01-01-2000 B 200 02-01-2000 A 1500 02-10-2000 D 1000 03-08-2000 Country_Info表: Engli 阅读全文