DECIMAL Data Type In MySQL,DECIMAL(M,D)andNUMERIC(M,D)are the same, and both have a precision of exactlyMdigits. Leftover Digits Number of Bytes001–213–425–637–94 For example, aDECIMAL(18,9)column has nine digits on either side of the decimal point, so the integer part and the ...
The SQL standard requires that the precision ofNUMERIC(M,D)beexactlyMdigits. ForDECIMAL(M,D), the standard requires a precision of at leastMdigits but permits more. In MySQL,DECIMAL(M,D)andNUMERIC(M,D)are the same, and both have a precision of exactlyMdigits. ...
For a full explanation of the internal format ofDECIMALvalues, see the filestrings/decimal.cin a MySQL source distribution. The format is explained (with an example) in thedecimal2bin()function.
mysql> insert into person values ('b'); Query OK, 1 row affected (0.01 sec) mysql> insert into person values ('B'); Query OK, 1 row affected (0.01 sec) mysql> select * from person where name ='a'; +---+ | name | +---+ | a | +---+ 1 row in set (0.00 sec) 1. ...
MySQL Workbench建表时 PK NN UQ BIN UN ZF AI 的含义 PK:Belongs to primary key 主键 NN:Not Null 非空 UQ:Unique index 唯一索引 BIN:Is binary column 二进制数据(比text更大的二进制数据) UN:Unsigned data type 无符号 整数(非负数) ZF:Fill up values for that column with 0's if it is nu...
3.1 MySQL 先来看看 MySQL decimal 相关的数据结构 typedefint32decimal_digit_t;structdecimal_t{intintg, frac, len;boolsign;decimal_digit_t*buf; }; AI代码助手复制代码 MySQL 的 decimal 使用一个长度为 len 的 decimal_digit_t (int32) 的数组 buf 来存储 decimal 的数字, 每个 decimal_digit_t 最...
DECIMAL类型用于存储高精度的十进制数值。在MySQL中,DECIMAL类型定义时必须指定精度(precision)和标度(scale)两个参数。 DECIMAL(precision,scale) 其中,precision是指总共可以存储多少位数字,scale是指小数位有多少个。 例如,DECIMAL(10, 2)数据类型就可以存储10位数字,其中小数点位于第8位,精度为2。也就是说,这种数...
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It's assumed that fixed-point values, DECIMAL and NUMERIC, in MySQL are not susceptible to rounding errors because they are exact numeric data types. Not true.
4 rows in set (0.01 sec) 插入几条数据看一下: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 mysql> insert into tc_integer values(1, 1, 1, 1); Query OK, 1 row affected (0.02 sec) ...