今天重新搞了一下JDBC，然後在寫程式碼的時候遇到了一個蛋疼的問題，糾結了很久，丟擲的異常如下：

資料庫連線成功！[email protected]
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:411)
    at com.mysql.jdbc.Util.getInstance(Util.java:386)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1054)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4237)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4169)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2617)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2778)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2819)
    at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1811)
    at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1725)
    at org.phn.dao.test.DBUtil.main(DBUtil.java:98)
**Error**: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
 

就是這一句

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

下面是我的程式碼

package org.phn.dao.test;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ResourceBundle;

/**
 * @author phn
 * @date 2015-4-8
 * @TODO 資料庫操作工具類
 */
public class DBUtil {
    static ResourceBundle rbundle = ResourceBundle.getBundle("db");
    private static String driverName = rbundle.getString("className");
    private static String dbUser = rbundle.getString("user");
    private static String dbPass = rbundle.getString("password");
    private static String dbUrl = rbundle.getString("url");

    /**
     * @date 2015-4-8
     * @TODO 獲取資料庫連線
     * @return Connection
     */
    public static Connection getConnection() {
        try {
            // 這裡使用這種方法已經指定了new出來的Driver是mysql的驅動
            // DriverManager.registerDriver(new Driver());
            Class.forName(driverName).newInstance();
            Connection conn = null;
            conn = DriverManager.getConnection(dbUrl, dbUser, dbPass);
            if (conn != null) {
                System.out.println("資料庫連線成功！conn=" + conn);
                return conn;
            }
        } catch (InstantiationException e) {
            // e.printStackTrace();
            System.out.println("**Error**:caused at " + DBUtil.class + "."
                    + new Throwable().getStackTrace()[0].getMethodName() + "::"
                    + e.getMessage());
        } catch (IllegalAccessException e) {
            // e.printStackTrace();
            System.out.println("**Error**:caused at " + DBUtil.class + "."
                    + new Throwable().getStackTrace()[0].getMethodName() + "::"
                    + e.getMessage());
        } catch (ClassNotFoundException e) {
            // e.printStackTrace();
            System.out.println("**Error**:caused at " + DBUtil.class + "."
                    + new Throwable().getStackTrace()[0].getMethodName() + "::"
                    + e.getMessage());
        } catch (SQLException e) {
            // e.printStackTrace();
            System.out.println("**Error**:caused at " + DBUtil.class + "."
                    + new Throwable().getStackTrace()[0].getMethodName() + "::"
                    + e.getMessage());
        }
        System.out.println("**Error**:資料庫連線失敗！");
        return null;
    }



    public static void main(String[] args) {
        try {
            Connection conn = getConnection();
            String insertSql = "INSERT INTO t_user(uname,upass) VALUES(?,?)";
            if (conn != null) {
                PreparedStatement pstm = conn.prepareStatement(insertSql);
                pstm.setString(1, "234");
                pstm.setString(2, "234");
                pstm.executeUpdate(insertSql);
            }
        } catch (SQLException e) {
            e.printStackTrace();
            System.out.println("**Error**:" + e.getMessage());
        }

    }
}
 

網上找了很多，然後終於在一位仁兄的部落格中遇到了類似的問題，下面是這個問題的解決辦法：

仔細看看我的main方法中的這一段：

PreparedStatement pstm = conn.prepareStatement(insertSql);
pstm.setString(1, "234");
pstm.setString(2, "234");
pstm.executeUpdate(insertSql);

PrepareStatement 的方法 executeUpdate 經過了過載，即有一個帶String sql引數的和一個沒有帶String sql引數的，這裡就是由於我使用了帶Sql語句引數的方法才導致出現這個問題的。

實際上使用executeUpdate（）的話sql語句中可以使用？作為引數傳遞。若使用executeUpdate（string sql）的話則不能使用sql語句中帶?引數。