sql 有什么问题？

Question

I'm worte the sql.

id="nana";
String queryNum = request.getParameter("id");

String query = "INSERT INTO likey (user, article) "
            +"SELECT {"+id+"}, {"+queryNum+"} FROM reviews "
            +"WHERE EXISTS ("
            +"SELECT num FROM reviews WHERE num={"+queryNum+"}) "
            +"AND NOT EXISTS("
            +"SELECT num FROM likey WHERE user ={"+id+"}"
            +"AND article ={"+id+"}) "
            +"LIMIT 1";
System.out.println(query);

pstmt = con.prepareStatement(query);
out.println("111");
pstmt.executeUpdate();
out.println("2222");

but It doesn't work.

What should I do?

Answer 1

Delete all curly brackets:

String query = "INSERT INTO likey (user, article) "
        +"SELECT "+id+", "+queryNum+" FROM reviews "
        +"WHERE EXISTS ("
        +"SELECT num FROM reviews WHERE num="+queryNum+") "
        +"AND NOT EXISTS("
        +"SELECT num FROM likey WHERE user ="+id
        +"AND article ="+id+") "
        +"LIMIT 1";