我来回浏览互联网,发现我的问题无法解决.

我试图使用参数绑定与jdbc查询mysql表,但它在我的语句中不断报告问号的语法错误.

这是我的班级：

package todoList_;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

import java.util.HashMap;

public class testBinding {

// JDBC driver name and database URL

static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";

static final String DB_URL = "jdbc:mysql://localhost/TODO?useJvmCharsetConverters=true";

// Database credentials

static final String USER = "root";

static final String PASS = "root";

public static void main(String args[]) {

// TODO Auto-generated method stub

Connection conn = null;

Statement stmt = null;

HashMap list = new HashMap();

try {

// STEP 2: Register JDBC driver

Class.forName("com.mysql.jdbc.Driver");

// STEP 3: Open a connection

System.out.println("Connecting to database...");

conn = DriverManager.getConnection(DB_URL, USER, PASS);

// STEP 4: Execute a query

System.out.println("Creating statement...");

stmt = conn.createStatement();

String sql;

sql = "select * from todos where `id` = ?";

PreparedStatement preparedStatement1 = conn.prepareStatement(sql);

preparedStatement1.setInt(1, 0);

ResultSet rs = preparedStatement1.executeQuery(sql);

// STEP 5: Extract data from result set

while (rs.next()) {

// Retrieve by column name

list.put(rs.getInt("id"), rs.getString("name"));

}

// STEP 6: Clean-up environment

rs.close();

stmt.close();

conn.close();

} catch (SQLException se) {

// Handle errors for JDBC

se.printStackTrace();

} catch (Exception e) {

// Handle errors for Class.forName

e.printStackTrace();

} finally {

// finally block used to close resources

try {

if (stmt != null)

stmt.close();

} catch (SQLException se2) {

} // nothing we can do

try {

if (conn != null)

conn.close();

} catch (SQLException se) {

se.printStackTrace();

} // end finally try

} // end try

}

}

这是我的日志：

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(Unknown Source)

at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)

at java.lang.reflect.Constructor.newInstance(Unknown Source)

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:1052)

at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3609)

at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3541)

at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2002)

at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2163)

at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2618)

at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2568)

at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1557)

at todoList_.testBinding.main(testBinding.java:41)

我正在使用mysql-connector-java-5.1.18-bin.jar,我已将其复制到WebContent / WEB-INF / lib并添加到项目的Build Path中.

我用Eclipse.

您能否提一些建议？

提前致谢.