Re: code example for PQgetCopyData

[Dave Huber <DHuber@xxxxxxxxxxxxxxxxxxxxxxxxxx>]

Tom,

Thanks for the help. Setting buffer to a char * fixed the crashing problem.

Now, I have a different issue. The result from PQgetCopyData is always 1 for every row of data returned. Does this not work for return data "WITH BINARY"? If I issue the same copy command to a file instead of STDOUT and examine the file contents, there is most definitely data for each row. The command going to the PQexec function is:

COPY (SELECT * FROM event_log_table) TO STDOUT WITH BINARY
Or
COPY (SELECT * FROM event_log_table) TO E'C:\\testfile' WITH BINARY

To reiterate, nLen in the following code always == 1:


                pResult = PQexec(pConn, szCopyStr);
                delete [] szCopyStr;

                // make sure we are in the copy out state before reading                        if (PGRES_COPY_OUT == PQresultStatus(pResult))
                {
                        // get the data
                        int i = 0;
                        while (nLen = PQgetCopyData(pConn, &buffer, false) > 0)
                        {
                ...


Thanks again.

Dave


Tom wrote:

One thing you're missing is that you should check that the result from
the PQexec actually shows successful entry into COPY_OUT state.
But I think the crash is because you're confused about the indirection
level.  buffer should be char *, not char **, and the argument ought to
be &buffer so that the function can assign to buffer.

                        regards, tom lane



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