mysql jdbc 綁定變量_JDBC MySql綁定變量文法錯誤在where子句中

我收到此錯誤：com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException：您的SQL文法有錯誤。檢查與您的MySQL伺服器版本相對應的手冊，以擷取在’？’附近使用的正确文法。在第1行

public static Person getDetails(int id) {

Connection conn = null;

PreparedStatement stmt = null;

Person newPerson = new Person();

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...");

String sql = "SELECT firstName, lastName, birthday FROM person WHERE id=?";

System.out.println("SQL Statement:\n\t" + stmt);

stmt = conn.prepareStatement(sql);

System.out.println("Prepared Statement before bind variables set:\n\t" + stmt.toString());

//Bind values into the parameters.

System.out.println("ID " + id);

stmt.setInt(1, id); // This would set id

System.out.println("Prepared Statement after bind variables set:\n\t" + stmt.toString());

// Let us select all the records and display them.

ResultSet rs = stmt.executeQuery(sql);

//STEP 5: Extract data from result set

while(rs.next()){

//Retrieve by column name

String firstName = rs.getString("firstName");

String lastName = rs.getString("lastName");

Date birthday = rs.getDate("birthday");

newPerson.setBirthday(birthday);

newPerson.setFirstName(firstName);

newPerson.setLastName(lastName);

newPerson.setId(id);

//Display values

System.out.print("ID: " + id);

System.out.print(", First: " + firstName);

System.out.println(", Last: " + lastName);

System.out.println(", Birthday: " + birthday);

}

//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

System.out.println("Goodbye!");

return newPerson;

}

我成功執行了不帶where子句的查詢。我看過許多示例，但我沒有嘗試解決此問題。