JDBC 难倒的 SQL 异常 [英] Stumped SQL Exception for JDBC

问题描述

我正在尽我所能让 JDBC 工作，现在唯一让我难受的是这个异常，我不知道:

I'm trying all I can to get a JDBC to work, the only thing that is stumping me right now is this exception, which I have no idea about:

com.mysql.jdbc.exceptions.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '????????????????' at line 1
    com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1049)
    com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3593)
    com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3525)
    com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1986)
    com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2140)
    com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2620)
    com.mysql.jdbc.ConnectionImpl.configureClientCharacterSet(ConnectionImpl.java:1890)
    com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3523)
    com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2386)
    com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2163)
    com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:794)
    com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:374)
    com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:305)
    java.sql.DriverManager.getConnection(libgcj.so.10)
    java.sql.DriverManager.getConnection(libgcj.so.10)

我用它来连接...

Class.forName("com.mysql.jdbc.Driver");
DriverManager.getConnection("jdbc:mysql://localhost:3306/mysql", "username", "password");

非常感谢！

推荐答案

相关部分:

com.mysql.jdbc.exceptions.MySQLSyntaxErrorException: You have an error in your SQL
syntax; check the manual that corresponds to your MySQL server version for the 
right syntax to use near '????????????????' at line 1
    ...
    com.mysql.jdbc.ConnectionImpl.configureClientCharacterSet(ConnectionImpl.java:1890)
    ...
    java.sql.DriverManager.getConnection(libgcj.so.10)

那些问号表示在配置客户端字符集的查询过程中存在严重的字符编码问题.

Those question marks indicate a serious character encoding problem during the query to configure the client charset.

作为第一次尝试，打开 my.cnf 文件并确保存在以下两个条目:

As first try, open the my.cnf file and ensure that the following two entries are present:

character_set_server=utf8
collation_server=utf8_general_ci

作为第二次尝试，将 GCJ 替换为 OpenJDK 或 Oracle (Sun) JDK 更强大.众所周知，GCJ 有其古怪之处.

As second try, replace the GCJ by OpenJDK or Oracle (Sun) JDK which are way more robust. The GCJ is namely known to have its oddities.

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