Oracle中CHAR与VARCHAR2的区别
CHAR与VARCHAR2都是Oracle的数据存储式。CHAR是定长的，VARCHAR2是变长。都可以存储字符串。 需要注意的是使用CHAR的时候。Select查询要注意定长的式。查询字符串的长度要刚好。多了少了都不能查不到数据。例如字段A为CHAR(10)。存“abcdefg”，长度不满10。
CHAR与VARCHAR2都是Oracle的数据存储格式。CHAR是定长的，VARCHAR2是变长。都可以存储字符串。
需要注意的是使用CHAR的时候。Select查询要注意定长的格式。查询字符串的长度要刚好。多了少了都不能查不到数据。例如字段A为CHAR(10)。存“abcdefg”，长度不满10。Oracle会用空格补满10位。你用"abcefg"作为查询字段时是查不出来的。这就是我花了一个下午调程序。总以为是程序写错了。到最后发现建表的人对这表用的是CHAR，而其他的表用的是VARCHAR2。我完败于细节。
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