How to get details of a particular column in database.

Question

Hi dear friends,
I am getting error while i try to get index information on a particular column.
here is the code.. why it gives me error
import java.sql.*;
import java.util.StringTokenizer;
public class TestIndex {
  final static String jdbcURL = "jdbc:timesten:client:CATSREPLICATION";
  final static String jdbcDriver = "com.timesten.jdbc.TimesTenClientDriver";
  final static String scheme = "CATSPROD";
  public static void main(java.lang.String[] args) {
    System.out.println("--- Database Viewer ---");
    try {
      Class.forName(jdbcDriver);
      Connection con = DriverManager.getConnection(jdbcURL, "", "");
      DatabaseMetaData dbmd = con.getMetaData();
      System.out.println("Driver Name: " + dbmd.getDriverName());
      System.out.println("Database Product: " + dbmd.getDatabaseProductName());
        // Get a list of all the indexes for this table
      // this MYSCHEME.TABLENAME has a composite unique key on 2 columns of it.
       * create table MYSCHEME.TABLENAME (id integer not null, name varchar(25) not null);
       * create unique key on MYSCHEME.TABLENAME(id,name);
        ResultSet indexList = dbmd.getIndexInfo(null,null,"MYSCHEME.TABLENAME",true,false);
        ResultSet columns = null;
        indexList.next();
        while(indexList.next()) {
          System.out.println(" Index Name: "+indexList.getString("INDEX_NAME"));
          String column = indexList.getString("COLUMN_NAME");
          System.out.println(" Column Name:"+column);
          columns =  dbmd.getColumns(null,"MYSCHEME","TABLENAME",column);
          System.out.println("---------------------------");
          System.out.println(columns.getString("IS_NULLABLE"));
          System.out.println("---------------------------");
        indexList.close();
      con.close();
    catch (ClassNotFoundException e) {
      System.out.println("Unable to load database driver class");
    catch (SQLException e) {
      System.out.println("SQL Exception: " + e.getMessage());
it give error
SQL Exception: Invalid cursor state
why?
thanks a lot
Veena
[ November 10, 2005: Message edited by: Veena Gupta ]

Answer 1

indexList.next();
while(indexList.next()) {You will be missing the first record due to this.
columns =
dbmd.getColumns(null,"MYSCHEME","TABLENAME",column);
System.out.println("---------------------------");
System.out.println(columns.getString("IS_NULLABLE"));You need to call columns.next() before using the getString(). If next() is not called, the cursor of the ResultSet is positioned before the first record and an attempting to read a record before positioning the cursor to the first record would result in an exception due to invalid cursor state.