Re: convert ResultSet object to CSV file

27 Oct 2006 18:04:09 -0700
<> ha escrito:

Is there an API that can convert object implementation of
java.sql.ResultSet to a CSV file in Java?

i.e. when I execute

Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery("SELECT a, b FROM TABLE1");

can I say something like: store this rs object in "C:\result.csv" file.

   public static void storeAsCSV(ResultSet rs,File f)
   throws IOException, SQLException {
      int ncols = rs.getMetaData().getColumnCount();
      FileOutputStream fos;
      Writer out =
     new OutputStreamWriter(
        new BufferedOutputStream(
           fos=new FileOutputStream(f,false)));
      for (int i=1; i<(ncols+1); i++) {
     if (i<ncols) out.append(","); else out.append("\r\n");
      while ( {
     for (int i=1; i<(ncols+1); i++) {
        if (i<ncols) out.append(","); else out.append("\r\n");

CSVQuote is left as an exercise for the reader, and depends on the
exact syntax expected by the target application; but it only needs to
examine each character of each string once.

I know I can write sequence of Java code that can achieve this, but it
becomes performance bottleneck when result set contains more than 1
million records.Is there an alternate way?

Do you mean that you think Java will inherently cause a
performance-bottleneck, or that your code seems to run slow? I'm
working on a way to invoke the perl DBI drivers and other modules from
Java; but I doubt it'll be faster than either pure Java code or pure
perl code.

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