Обсуждение: JDBC and getTableTypes problem

 I am having difficulty try to get the  getTableTypes()  interface  of  JDBC
 functioning correctly with Postgresql 6.3.2. When I try to loop through the
 TABLE_TYPE  attributes, all I can retrieve are 6 copies of the type 'SYSTEM
 INDEX'.

 I am running these versions of software:

    Postgresql 6.3.2

    JDK 1.1.6.V98-8-14

    FreeBSD 2.2.7

 Here is the output from my sample program:

instantiate postgresql.Driver
Connect to database
The following types of tables are available in PostgreSQL:
  SYSTEM INDEX
  SYSTEM INDEX
  SYSTEM INDEX
  SYSTEM INDEX
  SYSTEM INDEX
  SYSTEM INDEX


 Here is the program that generated this output:

import java.sql.*;

public class TableTypes {

   public static void main(String args[]) {

        String url = "jdbc:postgresql:mysql";
        Connection con;

        try {
            System.out.println("instantiate postgresql.Driver");
            Class.forName("postgresql.Driver");
            }
        catch(java.lang.ClassNotFoundException e) {
            System.err.print("ClassNotFoundException: ");
            System.err.println(e.getMessage());
            return;
            }

        try {
            System.out.println("Connect to database");
            con = DriverManager.getConnection(url,"","");

            DatabaseMetaData dbmd = con.getMetaData();
            String dbmsName = dbmd.getDatabaseProductName();
            ResultSet rs = dbmd.getTableTypes();
            System.out.print("The following types of tables are ");
            System.out.println("available in " + dbmsName + ": ");

            while(rs.next()) {
                String tableType = rs.getString("TABLE_TYPE");
                System.out.println("  " + tableType);
                }

            rs.close();
            con.close();
            }
         catch(SQLException ex) {
            System.err.println("SQLException: " + ex.getMessage());
            }
        }
   }


 Any insight you can offer would be greatly appreciated.  If someone has the
 time, maybe you could try this example on your system, and see if you get
 the same result.

 Thanks.

---
Jim C., President       | C A R R O L L - N E T, Inc.
201-488-1332            | New Jersey's Premier Internet Service Provider
www.carroll.com         |
                        | Want to make your business more competitive, and
                        | at the same time, decrease costs?  Ask about the
www.message-server.com  | Carroll-Net  Message Server.

On Sun, 23 Aug 1998, Jim Carroll wrote:

>
>  I am having difficulty try to get the  getTableTypes()  interface  of  JDBC
>  functioning correctly with Postgresql 6.3.2. When I try to loop through the
>  TABLE_TYPE  attributes, all I can retrieve are 6 copies of the type 'SYSTEM
>  INDEX'.

[snip]

>  Any insight you can offer would be greatly appreciated.  If someone has the
>  time, maybe you could try this example on your system, and see if you get
>  the same result.

Nicely spotted. I've just fixed the problem in getTableTypes() - it was
reusing the same object for each row, rather than creating a new one,
hence the last value is returned each time.

The fix will be in the 6.4 version of the driver.

>
>  Thanks.
>
> ---
> Jim C., President       | C A R R O L L - N E T, Inc.
> 201-488-1332            | New Jersey's Premier Internet Service Provider
> www.carroll.com         |
>                         | Want to make your business more competitive, and
>                         | at the same time, decrease costs?  Ask about the
> www.message-server.com  | Carroll-Net  Message Server.
>
>

--
       Peter T Mount peter@retep.org.uk
      Main Homepage: http://www.retep.org.uk
PostgreSQL JDBC Faq: http://www.retep.org.uk/postgres
 Java PDF Generator: http://www.retep.org.uk/pdf