注意mysql中一定要用decimal标识货币的值

注意mysql 中一定要用decimal标识货币的值&＃xff01;不要用float了&＃xff0c;举例说明&＃xff1a;



Create Table LedgerEntries

(

LedgerEntryID Int Primary Key Auto_Increment Not Null

,CustomerID Int Not Null

,Amount Float Not Null

);



然后插入一些数据&＃xff1b;

Insert Into LedgerEntries (CustomerID, Amount)

Values (1, 3.14);



Insert Into LedgerEntries (CustomerID, Amount)

Values (1, 30000.14);



最后查询下

Select * From LedgerEntries;



&＃43;---------------&＃43;------------&＃43;---------&＃43;

| LedgerEntryID | CustomerID | Amount |

&＃43;---------------&＃43;------------&＃43;---------&＃43;

| 1 | 1 | 3.14 |

| 2 | 1 | 30000.1 |

&＃43;---------------&＃43;------------&＃43;---------&＃43;





看到了么&＃xff1f;没了最后的一位&＃xff01;&＃xff0c;因此&＃xff0c;赶紧用decimal吧



Create Table LedgerEntries

(

LedgerEntryID Int Primary Key Auto_Increment Not Null

,CustomerID Int Not Null

,Amount Decimal(10,2) Not Null

);



Insert Into LedgerEntries (CustomerID, Amount)

Values (1, 3.14);



-- This is the largest value we can insert into a Decimal(10,2)

-- if we have two numbers to the right of the decimal point

Insert Into LedgerEntries (CustomerID, Amount)

Values (1, 99999999.99);



Select * From LedgerEntries;

&＃43;---------------&＃43;------------&＃43;-------------&＃43;

| LedgerEntryID | CustomerID | Amount |

&＃43;---------------&＃43;------------&＃43;-------------&＃43;

| 1 | 1 | 3.14 |

| 2 | 1 | 99999999.99 |

&＃43;---------------&＃43;------------&＃43;-------------&＃43;

2 rows in set (0.00 sec)