坑,绝对的大坑

今天上线新模块,昨天测试通过的代码,居然在线上报错.
报错信息模拟如下:


纳尼?
第一反应是程序哪里写错了
大家查了一上午,问题依旧,毫无头绪.
后来居然被本猫发现了问题(颇自豪啊)
这个其实是权限不足导致的.

模拟问题如下:

已经存在一个用户,对mvbox库下的表,有Insert,update,select权限.
grant select,insert,update on mvbox.* to li@'localhost' identified by 'li';

新建两个过程.

drop procedure if exists proc1;
drop procedure if exists proc2;

delimiter $$

create procedure proc1 (in para1 int , out para2 int)
begin
select para1 into para2;
end $$

create procedure proc2 (in para1 int , out para2 int)
begin
select para1 into para2;
end $$
delimiter ;

注意, 新建过程之后,没有对 li 帐号进行授权.

这时执行程序如下

import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Types;

public class T {
public static void main(String[] args) throws SQLException, ClassNotFoundException {
Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/mvbox", "li", "li");

CallableStatement cp = conn.prepareCall("{call proc1(?,?)}");
cp.setInt(1, 1);
cp.registerOutParameter(2, Types.INTEGER);
cp.execute();
System.out.println(cp.getInt(2));
cp.close();
conn.close();
}
}

执行之后,结果如下:


增加如下授权之后,再次执行
grant execute on procedure mvbox.proc1 to li@'localhost' identified by 'li';

还是报错,报错信息如下:
Exception in thread "main" java.sql.SQLException: User does not have access to metadata required to determine stored procedure parameter types. If rights can not be granted, configure connection with "noAccessToProcedureBodies=true" to have driver generate parameters that represent INOUT strings irregardless of actual parameter types.
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1094)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:997)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:983)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:928)
at com.mysql.jdbc.DatabaseMetaData.getCallStmtParameterTypes(DatabaseMetaData.java:1858)
at com.mysql.jdbc.DatabaseMetaData.getProcedureOrFunctionColumns(DatabaseMetaData.java:4508)
at com.mysql.jdbc.JDBC4DatabaseMetaData.getProcedureColumns(JDBC4DatabaseMetaData.java:106)
at com.mysql.jdbc.CallableStatement.determineParameterTypes(CallableStatement.java:857)
at com.mysql.jdbc.CallableStatement.<init>(CallableStatement.java:630)
at com.mysql.jdbc.JDBC4CallableStatement.<init>(JDBC4CallableStatement.java:46)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:408)
at com.mysql.jdbc.CallableStatement.getInstance(CallableStatement.java:524)
at com.mysql.jdbc.ConnectionImpl.parseCallableStatement(ConnectionImpl.java:4335)
at com.mysql.jdbc.ConnectionImpl.prepareCall(ConnectionImpl.java:4419)
at com.mysql.jdbc.ConnectionImpl.prepareCall(ConnectionImpl.java:4393)
at T.main(T.java:12)

这个报错信息就容易理解了,增加对proc表的select权限
grant select on mysql.proc to li@'localhost' identified by 'li';

再次执行,成功！！

这时候,如果访问proc2 过程,则报错如下:（当然会出错,因为没有对帐号li进行授权啊）
Exception in thread "main" com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: execute command denied to user 'li'@'localhost' for routine 'mvbox.proc2'
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:408)
at com.mysql.jdbc.Util.getInstance(Util.java:383)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1062)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4226)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4158)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2615)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2776)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2840)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2082)
at com.mysql.jdbc.PreparedStatement.execute(PreparedStatement.java:1302)
at com.mysql.jdbc.CallableStatement.execute(CallableStatement.java:921)
at T.main(T.java:15)

但是这个报错,明确显示了帐号li对于过程mvbox.proc2 没有执行权限.这样很容易定位解决问题.

在什么情况下,会因为权限不足而报Parameter number N is not an OUT parameter的错误呢?

就是该帐号没有任何execute的授权,而执行存储过程的时候,就会有上述报错.

并且仅仅是使用JDBC的途径,如果使用MySQL 的客户端,报错信息也是明确的..



MySQL JDBC的一个坑,一个专有大坑.