mirror of
https://github.com/postgres/postgres.git
synced 2026-06-04 06:45:49 -04:00
Bruce Momjian
135 lines
2.8 KiB
C
135 lines
2.8 KiB
C
/*
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* testlibpq.c
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* Test the C version of LIBPQ, the POSTGRES frontend library.
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*
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*
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*/
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#include <stdio.h>
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#include "libpq-fe.h"
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static void
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exit_nicely(PGconn *conn)
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{
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PQfinish(conn);
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exit(1);
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}
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int
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main()
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{
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char *pghost,
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*pgport,
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*pgoptions,
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*pgtty;
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char *dbName;
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int nFields;
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int i,
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j;
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#ifdef DEBUG
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FILE *debug;
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#endif /* DEBUG */
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PGconn *conn;
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PGresult *res;
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/*
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* begin, by setting the parameters for a backend connection if the
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* parameters are null, then the system will try to use reasonable
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* defaults by looking up environment variables or, failing that,
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* using hardwired constants
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*/
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pghost = NULL; /* host name of the backend server */
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pgport = NULL; /* port of the backend server */
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pgoptions = NULL; /* special options to start up the backend
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* server */
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pgtty = NULL; /* debugging tty for the backend server */
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dbName = "template1";
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/* make a connection to the database */
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conn = PQsetdb(pghost, pgport, pgoptions, pgtty, dbName);
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/* check to see that the backend connection was successfully made */
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if (PQstatus(conn) == CONNECTION_BAD)
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{
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fprintf(stderr, "Connection to database '%s' failed.\n", dbName);
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fprintf(stderr, "%s", PQerrorMessage(conn));
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exit_nicely(conn);
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}
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#ifdef DEBUG
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debug = fopen("/tmp/trace.out", "w");
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PQtrace(conn, debug);
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#endif /* DEBUG */
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/* start a transaction block */
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res = PQexec(conn, "BEGIN");
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if (PQresultStatus(res) != PGRES_COMMAND_OK)
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{
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fprintf(stderr, "BEGIN command failed\n");
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PQclear(res);
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exit_nicely(conn);
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}
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/*
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* should PQclear PGresult whenever it is no longer needed to avoid
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* memory leaks
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*/
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PQclear(res);
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/*
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* fetch instances from the pg_database, the system catalog of
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* databases
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*/
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res = PQexec(conn, "DECLARE myportal CURSOR FOR select * from pg_database");
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if (PQresultStatus(res) != PGRES_COMMAND_OK)
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{
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fprintf(stderr, "DECLARE CURSOR command failed\n");
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PQclear(res);
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exit_nicely(conn);
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}
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PQclear(res);
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res = PQexec(conn, "FETCH ALL in myportal");
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if (PQresultStatus(res) != PGRES_TUPLES_OK)
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{
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fprintf(stderr, "FETCH ALL command didn't return tuples properly\n");
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PQclear(res);
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exit_nicely(conn);
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}
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/* first, print out the attribute names */
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nFields = PQnfields(res);
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for (i = 0; i < nFields; i++)
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printf("%-15s", PQfname(res, i));
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printf("\n\n");
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/* next, print out the instances */
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for (i = 0; i < PQntuples(res); i++)
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{
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for (j = 0; j < nFields; j++)
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printf("%-15s", PQgetvalue(res, i, j));
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printf("\n");
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}
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PQclear(res);
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/* close the portal */
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res = PQexec(conn, "CLOSE myportal");
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PQclear(res);
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/* end the transaction */
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res = PQexec(conn, "END");
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PQclear(res);
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/* close the connection to the database and cleanup */
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PQfinish(conn);
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#ifdef DEBUG
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fclose(debug);
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#endif /* DEBUG */
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exit(0);
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}
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