Re: Performing COPY Command

From: "Rajan Bhide" <rbhide(at)nulinkinc(dot)com>
To: "Michael Glaesemann" <grzm(at)myrealbox(dot)com>, <pgsql-novice(at)postgresql(dot)org>
Subject: Re: Performing COPY Command
Date: 2004-02-10 14:15:13
Message-ID: FF851C7EEB75954F9BCFB5CA117AB1EC0BEF6A@delta.nulinkinc.com
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Hi,

Can u provide me the 'C' code snippet to execute it (with libpq).(Specially to PIPE stdin to psql server)
I tried with following but no success:

void performInsert()
{
char query_string[2048]; /* holds constructed SQL query */
PGconn *conn; /* holds database connection */
PGresult *res; /* holds query result */
/* connect to the database */
conn = PQconnectdb(DB_CONN_PARAM_STR);
/* connect to the database */

if (PQstatus(conn) == CONNECTION_BAD) /* did the connection fail? */
{
fprintf(stderr, "Connection to database failed.\n");
fprintf(stderr, "%s\n",PQerrorMessage(conn));
return;
}
else
{
fprintf(stderr, "Connection successful\n");
}


sprintf(query_string, "COPY testtable FROM stdin DELIMITERS ','");
fprintf(stdin,"123,");
fprintf(stdin,"abc");
fprintf(stdin,"\.");
fprintf(stderr,"QueryStr : %s\n",query_string);

res = PQexec(conn, query_string); /* send the query */
if (atoi(PQcmdTuples(res)) == 0)
{
fprintf(stderr, "Insert failed : %s\n",PQerrorMessage(conn));
break;
}

PQclear(res); /* free result */
PQfinish(conn); /* disconnect from the database */
}

Table structure:
Psql=>\d testtable
Column | Type | Modifiers
--------+---------+--------------------------------------------------
seqno | integer |
data | bytea |

I could succeed fetching the data from file,
but my code fails if the file contains non-printable characters saying "Bad input string for type bytea".

My contents from the file are:

1,\\000010203040506070809\\0120b0c0d0e0f101112131415161718191a1b1c1d1e1f20212223242526'28292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f404142434445464748494a4b4c4d4e4f505152535455565758595a5b\\5d5e5f606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9fa0a1a2a3a4a5a6a7a8a9aaabacadaeafb0b1b2b3b4b5b6b7b8b9babbbcbdbebfc0c1c2c3c4c5c6c7c8c9cacbcccdcecfd0d1d2d3d4d5d6d7d8d9dadbdcdddedfe0e1e2e3e4e5e6e7e8e9eaebecedeeeff0f1f2f3f4f5f6f7f8f9fafbfcfdfeff
\.

Basically its the hexsequence from 0X00-0XFF.

Thanks,
Rajan Bhide

-----Original Message-----
From: Michael Glaesemann [mailto:grzm(at)myrealbox(dot)com]
Sent: Tuesday, February 10, 2004 2:37 PM
To: Rajan Bhide
Subject: Re: [NOVICE] Performing COPY Command

Hi Rajan

On Feb 10, 2004, at 2:41 PM, Rajan Bhide wrote:

> How to perform COPY from memory instead of files?
> Any examples/pointers would be greatly appreciated.

I believe COPY works from STDIN if no file is specified, so if you can
pipe the data to STDIN, you should be golden. And the docs might help: <http://www.postgresql.org/docs/current/static/sql-copy.html>

Does this help?

Michael Glaesemann
grzm myrealbox com

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