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Decimal, Float, Double三種數據類型精度測試
巨大八爪鱼
武林盟主 二十一级
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Floor 1 Posted at: 5/24/15 11:50
CREATE TABLE IF NOT EXISTS `floats` (
  `DE` decimal(65,30) NOT NULL,
  `F` float NOT NULL,
  `DO` double NOT NULL,
  PRIMARY KEY (`DE`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_bin;

INSERT INTO `floats` (`DE`, `F`, `DO`) VALUES
('-12345678901234567890123.141592653589793238462643383279', 3.14159, 3.14159265358979);

巨大八爪鱼
武林盟主 二十一级
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Floor 2 Posted at: 5/24/15 11:51
注意:phpMyAdmin中的real類型就是double類型
巨大八爪鱼
武林盟主 二十一级
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Floor 3 Posted at: 5/24/15 11:51
decimal數據類型可以存儲-12345678901234567890123.141592653589793238462643383279這樣的一個數字!
巨大八爪鱼
武林盟主 二十一级
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Floor 4 Posted at: 5/24/15 11:54
Float只有6位有效數字
double則是14~16位
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Clicks: 1253 Replies: 3
Author: 巨大八爪鱼
Last reply: 巨大八爪鱼
Last reply time: 5/24/15 11:54
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