Vryjdfkk

I have a table like this:

mysql> describe transactions;

+-----------------------+---------------+------+-----+---------+----------------+

| Field                 | Type          | Null | Key | Default | Extra          |

+-----------------------+---------------+------+-----+---------+----------------+

| id                    | int(11)       | NO   | PRI | NULL    | auto_increment |

| cost                  | float(10,2)   | YES  |     | NULL    |                |

+-----------------------+---------------+------+-----+---------+----------------+

I (naively?) thought that would be a good way to store amounts.
I am 3 days from release, and I discovered this:

mysql> UPDATE transactions SET cost = 162295.99 WHERE id = 14891;

Query OK, 0 rows affected (0.01 sec)

Rows matched: 1  Changed: 0  Warnings: 0



mysql> select * from transactions where id = 14891;

+-------+---------------+

| id    | cost          |



+-------+---------------+

| 14891 |     162295.98 | 

+-------+---------------+

...?!? I entered .99, not .98!
So:

• Why is this doing it?


• How do I get out of this problem?


• 
  

  Would decimal work? I tried with:

  
  
  

  mysql> alter table transactions modify cost decimal(12,2) NULL DEFAULT NULL;
  Query OK, 1120 rows affected, 119 warnings (0.14 sec)
  Records: 1120 Duplicates: 0 Warnings: 119

  
  
  

  mysql>

  
  

However I am getting scary warnings. With "show warnings" I get:

mysql> show warnings;

+-------+------+---------------------------------------------+

| Level | Code | Message                                     |

+-------+------+---------------------------------------------+

| Note  | 1265 | Data truncated for column 'cost' at row 10  |

| Note  | 1265 | Data truncated for column 'cost' at row 369 |

| Note  | 1265 | Data truncated for column 'cost' at row 371 |

| Note  | 1265 | Data truncated for column 'cost' at row 378 |

| Note  | 1265 | Data truncated for column 'cost' at row 402 |

| Note  | 1265 | Data truncated for column 'cost' at row 403 |

+-------+------+---------------------------------------------

• How do I see which one "row 10" is anyway?




• KEY QUESTION: How do I get out of this hole safely?




• (Rhetorical question bonus question) Why didn't this happen like 3 months ago, when fixing would have been easy?