From 4076ca685941ac433bc91130e29449cef7858fba Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Sun, 24 Apr 2016 15:47:33 +0100
Subject: Support bulk selects which don't use cursors, always use of RETURNING

---
 libpqpp/pq-bulkselectcommand.cpp | 53 ++++++++++++++++++++++++++++++++++++++++
 libpqpp/pq-bulkselectcommand.h   | 29 ++++++++++++++++++++++
 libpqpp/pq-connection.cpp        |  5 ++++
 libpqpp/unittests/testpq.cpp     | 31 +++++++++++++++++++++++
 4 files changed, 118 insertions(+)
 create mode 100644 libpqpp/pq-bulkselectcommand.cpp
 create mode 100644 libpqpp/pq-bulkselectcommand.h

(limited to 'libpqpp')

diff --git a/libpqpp/pq-bulkselectcommand.cpp b/libpqpp/pq-bulkselectcommand.cpp
new file mode 100644
index 0000000..27674f5
--- /dev/null
+++ b/libpqpp/pq-bulkselectcommand.cpp
@@ -0,0 +1,53 @@
+#include "pq-bulkselectcommand.h"
+#include "pq-connection.h"
+#include "pq-column.h"
+#include "pq-error.h"
+
+PQ::BulkSelectCommand::BulkSelectCommand(Connection * conn, const std::string & sql, unsigned int no) :
+	DB::Command(sql),
+	DB::SelectCommand(sql),
+	PQ::Command(conn, sql, no),
+	executed(false)
+{
+	prepareSql(preparedSql, sql);
+}
+
+PQ::BulkSelectCommand::~BulkSelectCommand()
+{
+	if (execRes) {
+		PQclear(execRes);
+	}
+}
+
+void
+PQ::BulkSelectCommand::execute()
+{
+	if (!executed) {
+		execRes = c->checkResult(
+				PQexecParams(c->conn, preparedSql.c_str(), values.size(), NULL, &values.front(), &lengths.front(), NULL, 0),
+				PGRES_TUPLES_OK);
+		nTuples = PQntuples(execRes);
+		tuple = -1;
+		unsigned int nFields = PQnfields(execRes);
+		for (unsigned int f = 0; f < nFields; f += 1) {
+			insertColumn(DB::ColumnPtr(new Column(this, f)));
+		}
+		executed = true;
+	}
+}
+
+bool
+PQ::BulkSelectCommand::fetch()
+{
+	execute();
+	if (++tuple < nTuples) {
+		return true;
+	}
+	else {
+		PQclear(execRes);
+		execRes = NULL;
+		executed = false;
+		return false;
+	}
+}
+
diff --git a/libpqpp/pq-bulkselectcommand.h b/libpqpp/pq-bulkselectcommand.h
new file mode 100644
index 0000000..aeda42d
--- /dev/null
+++ b/libpqpp/pq-bulkselectcommand.h
@@ -0,0 +1,29 @@
+#ifndef PQ_BULKSELECTCOMMAND_H
+#define PQ_BULKSELECTCOMMAND_H
+
+#include <selectcommand.h>
+#include "pq-selectbase.h"
+#include "pq-command.h"
+#include <vector>
+#include <map>
+
+namespace PQ {
+	class Connection;
+	class Column;
+	class BulkSelectCommand : public DB::SelectCommand, public SelectBase, public Command {
+		public:
+			BulkSelectCommand(Connection *, const std::string & sql, unsigned int no);
+			virtual ~BulkSelectCommand();
+
+			bool fetch() override;
+			void execute() override;
+
+		private:
+			mutable bool executed;
+			std::string preparedSql;
+	};
+}
+
+#endif
+
+
diff --git a/libpqpp/pq-connection.cpp b/libpqpp/pq-connection.cpp
index 49867a4..078272e 100644
--- a/libpqpp/pq-connection.cpp
+++ b/libpqpp/pq-connection.cpp
@@ -1,5 +1,6 @@
 #include "pq-connection.h"
 #include "pq-error.h"
+#include "pq-bulkselectcommand.h"
 #include "pq-cursorselectcommand.h"
 #include "pq-modifycommand.h"
 #include <unistd.h>
@@ -97,6 +98,10 @@ PQ::Connection::ping() const
 DB::SelectCommand *
 PQ::Connection::newSelectCommand(const std::string & sql)
 {
+	// Yes, this is a hack
+	if (sql.find("libdbpp:no-cursor") != (std::string::size_type)-1) {
+		return new BulkSelectCommand(this, sql, pstmntNo++);
+	}
 	return new CursorSelectCommand(this, sql, pstmntNo++);
 }
 
diff --git a/libpqpp/unittests/testpq.cpp b/libpqpp/unittests/testpq.cpp
index 64d60d9..f5cb760 100644
--- a/libpqpp/unittests/testpq.cpp
+++ b/libpqpp/unittests/testpq.cpp
@@ -287,6 +287,37 @@ BOOST_AUTO_TEST_CASE( statementReuse )
 	delete ro;
 }
 
+BOOST_AUTO_TEST_CASE( bulkSelect )
+{
+	auto ro = DB::MockDatabase::openConnectionTo("pqmock");
+	auto sel = ro->newSelectCommand("SELECT * FROM test WHERE id > ? --libdbpp:no-cursor");
+	sel->bindParamI(0, 1);
+	int totalInt = 0, count = 0;
+	sel->forEachRow<int64_t>([&totalInt, &count](auto i) {
+			totalInt += i;
+			count += 1;
+		});
+	delete sel;
+	BOOST_REQUIRE_EQUAL(20, totalInt);
+	BOOST_REQUIRE_EQUAL(8, count);
+	delete ro;
+}
+
+BOOST_AUTO_TEST_CASE( insertReturning )
+{
+	auto ro = DB::MockDatabase::openConnectionTo("pqmock");
+	auto sel = ro->newSelectCommand("INSERT INTO test(id, fl) VALUES(1, 3) RETURNING id + fl --libdbpp:no-cursor");
+	int totalInt = 0, count = 0;
+	sel->forEachRow<int64_t>([&totalInt, &count](auto i) {
+			totalInt += i;
+			count += 1;
+		});
+	delete sel;
+	BOOST_REQUIRE_EQUAL(4, totalInt);
+	BOOST_REQUIRE_EQUAL(1, count);
+	delete ro;
+}
+
 BOOST_AUTO_TEST_CASE( closeOnError )
 {
 	auto ro = DB::ConnectionPtr(DB::MockDatabase::openConnectionTo("pqmock"));
-- 
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