Why Boolean execute(String SQL) is always true, even my input is not in my database

this is my code

 try{

        Class.forName("com.mysql.jdbc.Driver");
        String url = "jdbc:mysql://localhost/records";
        Connection con = DriverManager.getConnection(url,"root","");
        Statement st = con.createStatement();
        String sql = "SELECT * FROM patient_info WHERE name = '"+txt1.getText()+"' ";

in this part it always print true , if im right this boolean returns the boolean value of string sql

  Boolean ret = st.execute(sql);
       System.out.println(ret.toString());

this if statement i dont know if right

 if(ret == true){
           ResultSet rs = st.executeQuery(sql);
              String name = null;
            while(rs.next()) {
                name = rs.getString("name");
                txt2.setText(name);
                System.out.println("working"); 
            }
       rs.close();
       }else{
           txt2.setText("no records");
           System.out.println("no records");
       }
            st.close(); con.close();

    }catch(SQLException e){
        e.printStackTrace();
    }catch(ClassNotFoundException e){
        e.printStackTrace();
    }