Java SQL Prepared Statement Update not working-CodePudding

Hello I have the problem that I just can't get the following code to run. I've tried and changed all of them but I always get an error, maybe you have an idea where the error is?

public class TestCommand implements ServerCommand{

  

    @Override
    public void performcommand(SlashCommandInteractionEvent event, Member m, MessageChannelUnion channel,
            VoiceChannel ec, VoiceChannel pub, TextChannel log, Guild guild) {

                Connection connection = null;
                PreparedStatement preparedStatement = null;
                        
                        String sql = ("UPDATE member_ships SET?= ? WHERE UUID= ?"); 
                        
                        try {
                        connection = MySQL.getConnection();
                        preparedStatement = connection.prepareStatement(sql);
                        preparedStatement.setString(1,"Cyclone");
                        preparedStatement.setInt(2,9);
                        preparedStatement.setLong(3,316931131188576123l);
                        preparedStatement.executeUpdate();
                        
                        }   catch (SQLException e) {
                            e.printStackTrace();
                        } finally {
                            
                            MySQL.closePreparedStatement(preparedStatement);
                            MySQL.closeConnection(connection);
                        }
                    }
                }

The Mysql File

public class MySQL {

    public static Connection getConnection() throws SQLException {

        Connection connection = DriverManager.getConnection("jdbc:mysql://*****","***","****");
        connection.setAutoCommit(true);
        System.out.println("Database connecion successful"); //TODO Remove 
        return connection;

    }

And here the Error Code

java.sql.SQLSyntaxErrorException: 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 ''Cyclone'= 9 WHERE UUID= 316931131188576123' at line 1
        at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:120)
        at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:122)
        at com.mysql.cj.jdbc.ClientPreparedStatement.executeInternal(ClientPreparedStatement.java:916)
        at com.mysql.cj.jdbc.ClientPreparedStatement.executeUpdateInternal(ClientPreparedStatement.java:1061)
        at com.mysql.cj.jdbc.ClientPreparedStatement.executeUpdateInternal(ClientPreparedStatement.java:1009)
        at com.mysql.cj.jdbc.ClientPreparedStatement.executeLargeUpdate(ClientPreparedStatement.java:1320)
        at com.mysql.cj.jdbc.ClientPreparedStatement.executeUpdate(ClientPreparedStatement.java:994)

Update the Mysql database

CodePudding user response：

You can't bind obejct names (in this case, a column name), only values.

Having said that, since all the values here seem to be hard-coded, you really don't need a PreparedStamtement, and could just execute the statement directly:

con.executeUpdate("UPDATE member_ships SET Cyclone = 9 WHERE UUID = 316931131188576123l");