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oracle 数据类型

Jun 07, 2016 pm 03:07 PM
oracle data database core type

Oracle数据库的核心是表,表中的列使用到的常见数据类型如下: CHAR(length) 存储固定长度的字符串。参数length指定了长度,如果存储的字符串长度小于length,用空填充。 默认长度是1,最长不超过2000字节。 VARCHAR2(length) 存储可变长度的字符串。length

Oracle数据库的核心是表,表中的列使用到的常见数据类型如下:    
CHAR(length)   
 存储固定长度的字符串。参数length指定了长度,如果存储的字符串长度小于length,用空格填充。
 默认长度是1,最长不超过2000字节。
VARCHAR2(length)  
 存储可变长度的字符串。length指定了该字符串的最大长度。默认长度是1,最长不超过4000字符。
NUMBER(p,s)
 既可以存储浮点数,也可以存储整数,p表示数字的最大位数(如果是小数包括整数部分和小数部分
 和小数点,p默认是38为),s是指小数位数。
DATE 
 存储日期和时间,存储纪元、4位年、月、日、时、分、秒。
TIMESTAMP
 不但存储日期的年月日,时分秒,以及秒后6位,同时包含时区。
CLOB
 存储大的文本,比如存储非结构化的XML文档
BLOB
 存储二进制对象,如图形、视频、声音等。

示例:

格式                        输入的数字         实际的存储
NUMBER                1234.567         1234.567
NUMBER(6,2) 123.4567         123.46
NUMBER(4,2) 12345.67         输入的数字超过了所指定的精度,数据库不能存储

 

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