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MySQL 转义字符使用说明_MySQL

Jun 01, 2016 pm 01:19 PM

bitsCN.com MySQL的转义字符“/”
mfc_basic
MySQL识别下列转义字符:
/0
一个ASCII 0 (NUL)字符。
/n
一个新行符。
/t
一个定位符。 制符分隔
/r
一个回车符。
/b
一个退格符。
/'
一个单引号(“'”)符。
/"
一个双引号(“"”)符。
一个反斜线(“/”)符。
/%
一个“%”符。它用于在正文中搜索“%”的文字实例,否则这里“%”将解释为一个通配符。
/_
一个“_”符。它用于在正文中搜索“_”的文字实例,否则这里“_”将解释为一个通配符。
注意,如果你在某些正文环境中使用“/%”或“/%_”,这些将返回字符串“/%”和“/_”而不是“%”和“_”。
★★
有几种方法在一个字符串内包括引号:
1、必须转义的:
一个字符串用单引号“'”来引用的,该字符串中的单引号“'”字符可以用“''”方式转义。
一个字符串用双引号“"”来引用的,该字符串中的“"”字符可以用“""”方式转义。
同时你也可以继续使用一个转义字符“/”来转义
2、可不转义的:
一个字符串用双引号“"”来引用的,该字符串中的单引号“'”不需要特殊对待而且不必被重复或转义。
同理,
一个字符串用单引号“'”来引用的,该字符串中的双引号“"”不需要特殊对待而且不必被重复或转义。
下面显示的SELECT演示引号和转义如何工作:
mysql> SELECT 'hello', '"hello"', '""hello""', 'hel''lo', '/'hello';
+-------+---------+-----------+--------+--------+
¦ hello ¦ "hello" ¦ ""hello"" ¦ hel'lo ¦ 'hello ¦
+-------+---------+-----------+--------+--------+
mysql> SELECT "hello", "'hello'", "''hello''", "hel""lo", "/"hello";
+-------+---------+-----------+--------+--------+
¦ hello ¦ 'hello' ¦ ''hello'' ¦ hel"lo ¦ "hello ¦
+-------+---------+-----------+--------+--------+
mysql> SELECT "This/nIs/nFour/nlines";
+--------------------+
¦ This
Is
Four
lines ¦
+--------------------+
★★
如果你想要把二进制数据插入到一个BLOB列,下列字符必须由转义序列表示:
NUL
ASCII 0。你应该用'/0'(一个反斜线和一个ASCII '0')表示它。
ASCII 92,反斜线。用'//'表示。
'
ASCII 39,单引号。用“/'”表示。
"
ASCII 34,双引号。用“/"”表示。bitsCN.com

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