问题
I'm making an inventory system using Java and JDBC. I have got this error some how when querying a table.
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '?' at line 1
Below is the code
public static void SearchUser() throws SQLException{
String ordersquery = "SELECT * FROM orders WHERE submittedBy = ?";
User userDetails = UserController.getUserDetails(username);//gets the details from user tables
if (userDetails != null){
System.out.println("----Menu----");
System.out.println();
System.out.println("1. View Orders Made By This User");
System.out.println("2. View Most Expensive Parts Currently Taken Out By This User");
System.out.println();
System.out.println("9. Go Back To Main Menu");
choice = input.nextLine();
if (choice.equals("1")){
try (
PreparedStatement stmt2 = conn.prepareStatement(ordersquery);
){
stmt2.setInt(1, userDetails.getUserId());
ResultSet rsOrders = stmt2.executeQuery(ordersquery);
if (rsOrders != null){
while (rsOrders.next()){
Order orderDetails = new Order(rsOrders.getInt("orderId"), userDetails.getUserId(), rsOrders.getInt("totalItems"), rsOrders.getInt("totalPrice"));
System.out.println("-------------------------------------");
Order.print(orderDetails);
}
}
}catch (SQLException e){
System.err.println(e);
}
}else if (choice.equals("2")){
}
}
}
回答1:
ResultSet rsOrders = stmt2.executeQuery(ordersquery);
stmt2 is you sql query then why are you passing ordersquery change your code to below code
ResultSet rsOrders = stmt2.executeQuery();
回答2:
It seems you are using wrong sytax for executeQuery(). it doesn't expects parameter. Try below code. you should be good
public static void SearchUser() throws SQLException{
String ordersquery = "SELECT * FROM orders WHERE submittedBy = ?";
User userDetails = UserController.getUserDetails(username);//gets the details from user tables
if (userDetails != null){
System.out.println("----Menu----");
System.out.println();
System.out.println("1. View Orders Made By This User");
System.out.println("2. View Most Expensive Parts Currently Taken Out By This User");
System.out.println();
System.out.println("9. Go Back To Main Menu");
choice = input.nextLine();
if (choice.equals("1")){
try (
PreparedStatement stmt2 = conn.prepareStatement(ordersquery);
){
stmt2.setInt(1, userDetails.getUserId());
ResultSet rsOrders = stmt2.executeQuery();
if (rsOrders != null){
while (rsOrders.next()){
Order orderDetails = new Order(rsOrders.getInt("orderId"), userDetails.getUserId(), rsOrders.getInt("totalItems"), rsOrders.getInt("totalPrice"));
System.out.println("-------------------------------------");
Order.print(orderDetails);
}
}
}catch (SQLException e){
System.err.println(e);
}
}else if (choice.equals("2")){
}
}
}
来源：https://stackoverflow.com/questions/49841237/you-have-an-error-in-your-sql-syntax-check-the-manual-that-corresponds-to-your