Reading data from a set of tables

Question

Hi,
I am writing code to extract the data from several tables in a database. For each table, I am dynamically getting the number of fields or columns in the table and using Resultset obtaining the data in every field for each row. I do this using the getObject() method. Once I get the data for every field, I then want to insert this data into another table and for this I am using setObject() method. I am using these methods because the type of each field will be known only at runtime. After I do this, I do executeUpdate() in order to insert the data into the new table.
The problem is here -
At times it just inserts a few rows / records in the new table or it just gets and sets the Object for the first Row/Record in the table and then it freezes.
Is there any problem with the getObject() and setObject() methods?
while(rs.next())
for (int i =1; i <= rsmd.getColumnCount(); i++)
obj = rs.getObject(i);
System.out.println("Object received " + obj);
pstmt.setObject(i,obj);
System.out.println("Object set : "+ obj);
pstmt.executeUpdate();
} // end of while
Thanks in advance,
Nik

Answer 1

I don't know which DBMS/JDBC driver you are using. But there are drivers out there which do not permit two open Statements on the same connection. Maybe that is your problem. Try to close the ResultSet and the SELECT statement before the executeUpdate() of the second statement
Another thing to check: are you sure the column order for the SELECT and the INSERT is identical (in other words, are you building the INSERT based on the information received from the ResultSet?)
When it freezes, what do you mean with that? Where exactly does it "freeze"?
This might be a DB lock which your program is waiting for - some DBMS do a page/table lock when updating, so a different statement could block your statement.
Thomas