mysql jdbc 占位符_mysql-JDBC使用占位符的插入语句插入不成功是什么原因

……public static void insert(String name,String password) throws Exception{ Connection conn = null; PreparedStatement st = null; ResultSet rs =null; conn = DbUtils.getConn(); String sql="insert into User(name,password) values(?,?)"; st = conn.prepareStatement(sql); st.setString(1,name); st.setString(2, password); int num = st.executeUpdate(sql); if(num>0){ System.out.println("插入成功!!"); } DbUtils.release(conn, st, rs); } public static void main(String args[]) throws Exception{ …… IUserDao.insert("hello","89790"); …… }}

+----------+--------------+------+-----+---------+-------+

| Field | Type | Null | Key | Default | Extra |

+----------+--------------+------+-----+---------+-------+

| userID | int(11) | YES | | NULL | |

| name | varchar(255) | YES | | NULL | |

| sex | varchar(255) | YES | | NULL | |

| birthday | date | YES | | NULL | |

| password | varchar(255) | YES | | NULL | |

+----------+--------------+------+-----+---------+-------+

一直报错,但是不知道是怎么错了。求教 orz

Exception in thread "main" com.mysql.jdbc.exceptions.jdbc4.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

at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)

at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)

at java.lang.reflect.Constructor.newInstance(Constructor.java:526)

at com.mysql.jdbc.Util.handleNewInstance(Util.java:404)

at com.mysql.jdbc.Util.getInstance(Util.java:387)

at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:939)

at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3878)

at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3814)

at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2478)

at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2625)

at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2547)

at com.mysql.jdbc.StatementImpl.executeUpdateInternal(StatementImpl.java:1541)

at com.mysql.jdbc.StatementImpl.executeLargeUpdate(StatementImpl.java:2605)

at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1469)

at dao.IUserDao.insert(IUserDao.java:107)

at dao.IUserDao.main(IUserDao.java:120)

表名没错,id不是自增的,没有primarykey。把sql写死是可以插入的,用“?”就不行了,为什么呢?


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