MySQL DECIMALタイプ

mysql> use test;Database changed
mysql> create table teacher(score decimal(6, 2));Query OK, 0 rows affected (0.04 sec)
mysql> insert into teacher values(34.35464), (23534523.45434), ('3223.3557');Query OK, 3 rows affected, 3 warnings (0.04 sec)Records: 3  Duplicates: 0  Warnings: 3
mysql> select * from teacher;+---------+| score   |+---------+|   34.35 || 9999.99 || 3223.36 |+---------+3 rows in set (0.00 sec)

# decimal    
mysql> insert into teacher values(-4508.90764);

Query OK, 1 row affected, 1 warning (0.08 sec)



mysql> select * from teacher;

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

| score    |

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

|    34.35 |

|  9999.99 |

|  3223.36 |

| -4508.91 |

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

4 rows in set (0.00 sec)



mysql>

 

# decimal       '7956.54768'


mysql> insert into teacher values('7956.54768');

Query OK, 1 row affected, 1 warning (0.04 sec)



mysql> select * from teacher;

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

| score    |

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

|    34.35 |

|  9999.99 |

|  3223.36 |

| -4508.91 |

|  7956.55 |

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

5 rows in set (0.00 sec)



mysql>

(1)DECIMALタイプはFLOATとDOUBLEとは異なり,ここでDECIMALは実際にはシリアルで格納されている.
(2)DECIMAL(6,2)は、-9999.99から9999.99までのすべての値を表すことができ、符号と小数点を格納することができる.