如何停止对MySQL十进制字段进行四舍五入? [英] How do I stop a MySQL decimal field from being rounded?

问题描述

我在MySQL中有一个表，该表的字段为小数，长度9，无符号.我用它来定价.

I have a table in MySQL with a field that is decimal, length 9, unsigned. I'm using it for prices.

插入数据并查询后，所有数据均已四舍五入，小数点已删除.

After I insert the data, and query for it, it has all been rounded and the decimal has been removed.

我对为什么感到困惑.

故障排除技巧?

主机:web.com

phpMyAdmin版本:2.11.10.1

phpMyAdmin version: 2.11.10.1

MySQL客户端版本:5.0.95

推荐答案

MySQL中的小数类型有两个调整旋钮:精度和小数位.您省略了小数位，因此默认为0.

Decimal type in MySQL has two tuning knobs: precision and scale. You omitted the scale, so it defaults to 0.

DECIMAL列的声明语法为DECIMAL(M，D). MySQL 5.1中参数的值范围如下:

The declaration syntax for a DECIMAL column is DECIMAL(M,D). The ranges of values for the arguments in MySQL 5.1 are as follows:

M是最大位数(精度).范围是1到65.(较早版本的MySQL允许范围是1到254.)

M is the maximum number of digits (the precision). It has a range of 1 to 65. (Older versions of MySQL permitted a range of 1 to 254.)

D是小数点右边的位数(小数位数).范围是0到30，并且不能大于M.

D is the number of digits to the right of the decimal point (the scale). It has a range of 0 to 30 and must be no larger than M.

示例

mysql> create table test01 (field01 decimal(9));
Query OK, 0 rows affected (0.01 sec)

mysql> insert into test01 (field01) values (123.456);
Query OK, 1 row affected, 1 warning (0.00 sec)

mysql> select * from test01;
+---------+
| field01 |
+---------+
|     123 |
+---------+
1 row in set (0.00 sec)

mysql> create table test02 (field01 decimal(9, 4));
Query OK, 0 rows affected (0.00 sec)

mysql> insert into test02 (field01) values (123.456);
Query OK, 1 row affected (0.01 sec)

mysql> select * from test02;
+----------+
| field01  |
+----------+
| 123.4560 |
+----------+
1 row in set (0.00 sec)

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