java - 特殊字符未保存在数据库中

Question

我正在插入带有特殊字符的字符串，但显示问号(“？”)

代码-

  String mainquery = "INSERT INTO thread_pitch_gauge ( nominal_value, ob1, ob2) VALUES(?,?,?)";
                    String n1 = 56°± 116’;
                    String n2 = 56° 16’ 44’’;
                    String n3 = 56° 16’ 45’’;                   
                    ps = (PreparedStatement) connection.prepareStatement(mainquery);
                    ps.setInt(1, n1);
                    ps.setString(2, n2);
                    ps.setString(3, n3);                                    
                    ps.execute();
                     ps.close();
in database value showing like
nominal_value=56°± 116’
ob1=56° 16’ 44’’
ob2=56° 16? 45?;

我的数据库表所有字段类型都是varchar(50)我在java中遇到这个问题数据库是mysql请帮我提前致谢

Answer 1

在插入数据库之前需要转义特殊字符

There are a number of special characters that needs to be escaped (protected), if you want to include them in a character string. Here are some basic character escaping rules:

以下是如何包含特殊字符的一些示例:

SELECT 'It''s Sunday!' FROM DUAL;
It's Sunday! 

SELECT 'Allo, C\'est moi.' FROM DUAL;
Allo, C'est moi.

SELECT 'Mon\tTue\tWed\tThu\tFri' FROM DUAL;
   Mon   Tue     Wed     Thu     Fri

http://dba.fyicenter.com/faq/mysql/Escape-Special-Character.html