60 lines
1.4 KiB
C
60 lines
1.4 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <libpq-fe.h>
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void do_exit(PGconn *conn) {
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PQfinish(conn);
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exit(1);
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}
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int main(int argc, char **argv) {
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/*declaration*/
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const char *conninfo;
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printf("main() Started...\n");
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/*read command line*/
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if (argc > 1){
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printf("main() argv[1]: %s\n", argv[1]);
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conninfo = argv[1];
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}else{
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fprintf(stderr, "Usage: %s <connection info>\n", argv[0]);
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return 1;
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}
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/*connect to database*/
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PGconn *conn = PQconnectdb(conninfo);
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if (PQstatus(conn) == CONNECTION_BAD) {
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fprintf(stderr, "Connection to database failed: %s\n",
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PQerrorMessage(conn));
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do_exit(conn);
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}else if(PQstatus(conn)==CONNECTION_OK){
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printf("main() connected to database\n");
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}else{
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printf("main() connection status NOT known\n");
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}
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char *user = PQuser(conn);
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char *db_name = PQdb(conn);
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char *pswd = PQpass(conn);
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printf("User: %s\n", user);
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printf("Database name: %s\n", db_name);
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printf("Password: %s\n", pswd);
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/*retrive server of database using SQL statement*/
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/*PGRES_TUPLS_OK is returned for a query that returns data*/
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PGresult *res = PQexec(conn, "SELECT VERSION()");
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if (PQresultStatus(res) != PGRES_TUPLES_OK) {
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printf("No data retrieved\n");
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PQclear(res);
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do_exit(conn);
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}
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/*return a single field value of one row*/
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printf("%s\n", PQgetvalue(res, 0, 0));
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PQclear(res);
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PQfinish(conn);
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return 0;
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}
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