Strange SQLException : column not found

Question

Hello All,
I have seen many users facing the error : java.sql.SQLException : column not found. I have the same problem, although my case doesnot match with theirs.
I have a Base DAO class which establishes the connection with database in MySQL.I have no problem in establishing the connection. I have a extended DAO class for accessing the table 'product' in the database. I have a method in the extended class that retrieves the products under a category.
public ResultSet getProducts(String categoryName) {
          Connection con = super.getConnection();
          String query = "SELECT * FROM product WHERE sectionId = \'" + categoryName + "\'";
          System.out.println("Query = " + query);
          try {
               Statement stmt = con.createStatement();
               ResultSet rs = stmt.executeQuery(query);               
               return rs;
          } catch (Exception e) {
               System.out.println("Unable to retrieve products for category " + categoryName);
               e.printStackTrace();
          return null;
     }There is a helper method that displays the contents of the ResultSet. I have a main method that calls the above function and everything works fine.
Now coming to strange part !!! The same function displays an error "java.sql.SQLException : Column not found" when called using Struts Action Object.
The Struts Action object calls a Service method (ProductService.java) which then calls the above extended DAO class to retrieve sub categories and products of a category. I am using a similar select query for retrieving the sub categories and it works fine.
I am pretty sure that I am using the correct field name. Any help would be a help for me....
Thanks,
Praveen.

Answer 1

Couldn't you rephrase your SQL query to
SELECT column1, column2 ..... columnN FROM product WHERE sectionId = ?(i.e., enumerate the columns instead of relying on the "*" syntax)
use a PreparedStatement
use stmt.setString(1, categoryName)
and get the columns by number (starting from column 1)?
Sometimes the error "column not found" is really the case of the column being not found, because the version of the table that your DBA has installed in the DB has not the column that you expect to find in the table...