1 files changed, 127 insertions, 0 deletions
diff --git a/src/test/examples/testlibpq4.c b/src/test/examples/testlibpq4.c
new file mode 100644
index 0000000000..5e04097119
--- /dev/null
+++ b/src/test/examples/testlibpq4.c
@@ -0,0 +1,127 @@
+/*
+ * testlibpq4.c
+ * 	this test programs shows to use LIBPQ to make multiple backend
+ * connections
+ *
+ *
+ */
+#include <stdio.h>
+#include "libpq-fe.h"
+
+void 
+exit_nicely(PGconn* conn1, PGconn* conn2)
+{
+    if (conn1)
+	PQfinish(conn1);
+    if (conn2)
+	PQfinish(conn2);
+    exit(1);
+}
+
+void check_conn(PGconn* conn)
+{
+  /* check to see that the backend connection was successfully made */
+  if (PQstatus(conn) == CONNECTION_BAD) {
+    fprintf(stderr,"Connection to database '%s' failed.\n", dbName);
+    fprintf(stderr,"%s",PQerrorMessage(conn));
+    exit(1);
+  }
+}
+
+main()
+{
+  char *pghost, *pgport, *pgoptions, *pgtty;
+  char* dbName1, dbName2;
+  char* tblName;
+  int nFields;
+  int i,j;
+
+  PGconn* conn1, conn2;
+  PGresult* res1, res2;
+
+  if (argc != 4) 
+      {
+	  fprintf(stderr,"usage: %s tableName dbName1 dbName2\n",argv[0]);
+	  fprintf(stderr,"      compares two tables in two databases\n");
+	  exit(1);
+      }
+  tblName = argv[1];
+  dbName1 = argv[2];
+  dbName2 = argv[3];
+  
+
+  /* begin, by setting the parameters for a backend connection
+     if the parameters are null, then the system will try to use
+     reasonable defaults by looking up environment variables 
+     or, failing that, using hardwired constants */
+  pghost = NULL;  /* host name of the backend server */
+  pgport = NULL;  /* port of the backend server */
+  pgoptions = NULL; /* special options to start up the backend server */
+  pgtty = NULL;     /* debugging tty for the backend server */
+
+  /* make a connection to the database */
+  conn1 = PQsetdb(pghost, pgport, pgoptions, pgtty, dbName1);
+  check_conn(conn1);
+
+  conn2 = PQsetdb(pghost, pgport, pgoptions, pgtty, dbName2);
+  check_conn(conn2);
+
+  /* start a transaction block */
+  res1 = PQexec(conn1,"BEGIN"); 
+  if (PQresultStatus(res1) != PGRES_COMMAND_OK) {
+    fprintf(stderr,"BEGIN command failed\n");
+    PQclear(res1);
+    exit_nicely(conn1,conn2);
+  }
+  /* should PQclear PGresult whenever it is no longer needed to avoid
+     memory leaks */
+  PQclear(res1); 
+
+  /* fetch instances from the pg_database, the system catalog of databases*/
+  res = PQexec(conn,"DECLARE myportal CURSOR FOR select * from pg_database");
+  if (PQresultStatus(res) != PGRES_COMMAND_OK) {
+    fprintf(stderr,"DECLARE CURSOR command failed\n");
+    PQclear(res);
+    exit_nicely(conn);
+  }
+  PQclear(res);
+
+  res = PQexec(conn,"FETCH ALL in myportal");
+  if (PQresultStatus(res) != PGRES_TUPLES_OK) {
+    fprintf(stderr,"FETCH ALL command didn't return tuples properly\n");
+    PQclear(res);
+    exit_nicely(conn);
+  }
+ 
+  /* first, print out the attribute names */
+  nFields = PQnfields(res);
+  for (i=0; i < nFields; i++) {
+    printf("%-15s",PQfname(res,i));
+  }
+  printf("\n\n");
+
+  /* next, print out the instances */
+  for (i=0; i < PQntuples(res); i++) {
+    for (j=0  ; j < nFields; j++) {
+      printf("%-15s", PQgetvalue(res,i,j));
+    }
+    printf("\n");
+  }
+
+  PQclear(res);
+  
+  /* close the portal */
+  res = PQexec(conn, "CLOSE myportal");
+  PQclear(res);
+
+  /* end the transaction */
+  res = PQexec(conn, "END");
+  PQclear(res);
+
+  /* close the connection to the database and cleanup */
+  PQfinish(conn);
+
+/*   fclose(debug); */
+}
+  
+