oracle查询特殊字符-escape

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　　当表中有特殊字符时，可以使用escape进行查询，官方描述如下:
　　The pattern can contain special pattern-matching characters:

• 　　An underscore (_) in the pattern matches exactly one character (as opposed to one byte in a multibyte character set) in the value.
  
  
• 　　A percent sign (%) in the pattern can match zero or more characters (as opposed to bytes in a multibyte character set) in the value. The pattern '%' cannot match a null.
  
  

　　You can include the actual characters % or _ in the pattern by using the ESCAPE clause, which>% or _ in the pattern, then Oracle interprets this character literally in the pattern rather than as a special pattern-matching character. You can also search for the escape character itself by repeating it. For example, if @ is the escape character, then you can use @@ to search for @.
　　ESCAPE Clause Example The following example searches for employees with the pattern A_B in their name:
　　

　　
SELECT last_name
　　
FROM employees
　　
WHERE last_name LIKE '%A\_B%' ESCAPE '\';
　　

　　

　　


　　The ESCAPE clause>