From: Bruce Momjian <bruce@momjian.us>
Date: Mon, 23 Jun 2008 21:10:49 +0000 (+0000)
Subject: Add libpq comment about how to determine the format used for passing
X-Git-Tag: recoveryinfrav9~914
X-Git-Url: http://waps.l3s.uni-hannover.de/gitweb/?a=commitdiff_plain;h=804afb833eb2f9678d21e9ccc06435e40c062ba3;p=users%2Fsimon%2Fpostgres.git

Add libpq comment about how to determine the format used for passing
binary values.

Add comments to libpq C function for parameter passing.
---

diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index a052150520..5c2db0ef81 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -1397,6 +1397,14 @@ PGresult *PQexecParams(PGconn *conn,
             If the array pointer is null then all parameters are presumed
             to be text strings.
            </para>
+           <para>
+            Values passed in binary format require knowlege of
+            the internal representation expected by the backend.
+            For example, integers must be passed in network byte
+            order.  Passing <type>numeric</> values requires
+            knowledge of the server storage format, as implemented
+            in <filename>src/backend/utils/adt/numeric.c</>.
+           </para>
           </listitem>
          </varlistentry>
 
diff --git a/src/interfaces/libpq/fe-exec.c b/src/interfaces/libpq/fe-exec.c
index 97bfcf990f..37f3f9946e 100644
--- a/src/interfaces/libpq/fe-exec.c
+++ b/src/interfaces/libpq/fe-exec.c
@@ -976,12 +976,13 @@ PQsendQueryGuts(PGconn *conn,
 			goto sendFailed;
 	}
 
-	/* construct the Bind message */
+	/* Construct the Bind message */
 	if (pqPutMsgStart('B', false, conn) < 0 ||
 		pqPuts("", conn) < 0 ||
 		pqPuts(stmtName, conn) < 0)
 		goto sendFailed;
 
+	/* Send parameter formats */
 	if (nParams > 0 && paramFormats)
 	{
 		if (pqPutInt(nParams, 2, conn) < 0)
@@ -1001,6 +1002,7 @@ PQsendQueryGuts(PGconn *conn,
 	if (pqPutInt(nParams, 2, conn) < 0)
 		goto sendFailed;
 
+	/* Send parameters */
 	for (i = 0; i < nParams; i++)
 	{
 		if (paramValues && paramValues[i])