====== Description ======
Table: relation_company stores the relationship of listed companies.
====== Data Schema ======
^ Field      ^ Type       ^ NULL         ^Key         ^Default      ^Extra ^
| id| INT(11)| | | | the unique identifier of every record in this table|
| stock_id1 | INT(11) | | | | |
| stock_id2 | INT(11) | | | | |
| weight | DOUBLE(20,10) | | | | the value of relation|
| year | INT(11) | | | | |
| nweight | DOUBLE(20,10) | | | | the normolized weight|

====== Record Example ======
^id ^stock_id1 ^stock_id2 ^weight ^year ^nweight ^
| 1 | 1 | 601328 | 9.696827534 | 2011 | 0.1336089177 |
| 2 | 1 | 300234 | 0.07141842 | 2011 | 0.0009840474 |
| 3 | 1 | 428 | 1.34609049 | 2011 | 0.0185472716 |
| 4 | 1 | 783 | 0.0793538 | 2011 | 0.001093386 |
| 5 | 1 | 2059 | 0.07141842 | 2011 | 0.0009840474 |
| 6 | 1 | 600015 | 0.16664298 | 2011 | 0.0022961106 |
| 7 | 1 | 600016 | 2.91014732 | 2011 | 0.0400978188 |
| 8 | 1 | 600754 | 0.07141842 | 2011 | 0.0009840474 |
| 9 | 1 | 600837 | 1.20315994 | 2011 | 0.0165778856 |
| 10 | 1 | 600895 | 0.1505495 | 2011 | 0.0020743646 |

====== Change Log ======