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mysql> select * from Stock;
+------+----------+
| ID | Name |
+------+----------+
| 1 | 青岛啤酒 |
| 2 | 海尔集团 |
| 3 | 魏桥创业 |
+------+----------+
3 rows in set (0.00 sec)
mysql> select * from Data;
+---------+------------+------+
| StockID | Date | open |
+---------+------------+------+
| 3 | 2009-09-09 | 0.34 |
| 1 | 2009-09-08 | 0.45 |
| 2 | 2009-09-08 | 0.23 |
| 3 | 2009-09-08 | 0.36 |
+---------+------------+------+
4 rows in set (0.00 sec)
mysql> select s.ID,s.Name,if(d.dd='2009-09-09',1,0) sign
-> from Stock s inner join
-> (select StockID,max(Date) dd from Data group by StockID)d
-> where s.id = d.StockID;
+------+----------+------+
| ID | Name | sign |
+------+----------+------+
| 1 | 青岛啤酒 | 0 |
| 2 | 海尔集团 | 0 |
| 3 | 魏桥创业 | 1 |
+------+----------+------+
3 rows in set (0.00 sec)