Actually, don't prepare statement upfront during construction as it might not be valid (e.g. uncreated temp tables)

3 files changed, 11 insertions, 8 deletions

diff --git a/libpqpp/pq-modifycommand.cpp b/libpqpp/pq-modifycommand.cpp
index e140f0a..caad5c6 100644
--- a/libpqpp/pq-modifycommand.cpp
+++ b/libpqpp/pq-modifycommand.cpp
@@ -7,7 +7,7 @@ PQ::ModifyCommand::ModifyCommand(Connection * conn, const std::string & sql, uns
 	DB::Command(sql),
 	DB::ModifyCommand(sql),
 	PQ::Command(conn, sql, no),
-	pstmt(prepare()->second)
+	pstmt(nullptr)
 {
 }
 
@@ -15,26 +15,29 @@ PQ::ModifyCommand::~ModifyCommand()
 {
 }
 
-PQ::Connection::PreparedStatements::const_iterator
+const char *
 PQ::ModifyCommand::prepare() const
 {
+	if (pstmt) {
+		return pstmt;
+	}
 	auto hash(std::hash<std::string>()(sql));
 	auto i = c->preparedStatements.find(hash);
 	if (i != c->preparedStatements.end()) {
-		return i;
+		return (pstmt = i->second.c_str());
 	}
 	std::string psql;
 	psql.reserve(sql.length() + 20);
 	prepareSql(psql, sql);
 	c->checkResultFree(PQprepare(
 				c->conn, stmntName.c_str(), psql.c_str(), values.size(), NULL), PGRES_COMMAND_OK);
-	return c->preparedStatements.insert({hash, stmntName}).first;
+	return (pstmt = c->preparedStatements.insert({hash, stmntName}).first->second.c_str());
 }
 
 unsigned int
 PQ::ModifyCommand::execute(bool anc)
 {
-	PGresult * res = PQexecPrepared(c->conn, pstmt.c_str(), values.size(), &values.front(), &lengths.front(), NULL, 0);
+	PGresult * res = PQexecPrepared(c->conn, prepare(), values.size(), &values.front(), &lengths.front(), NULL, 0);
 	c->checkResult(res, PGRES_COMMAND_OK, PGRES_TUPLES_OK);
 	unsigned int rows = atoi(PQcmdTuples(res));
 	PQclear(res);
diff --git a/libpqpp/pq-modifycommand.h b/libpqpp/pq-modifycommand.h
index ed8b622..79593a1 100644
--- a/libpqpp/pq-modifycommand.h
+++ b/libpqpp/pq-modifycommand.h
@@ -14,8 +14,8 @@ namespace PQ {
 			unsigned int execute(bool) override;
 
 		private:
-			Connection::PreparedStatements::const_iterator prepare() const;
-			const std::string pstmt;
+			const char * prepare() const;
+			mutable const char * pstmt;
 	};
 }
 
diff --git a/libpqpp/unittests/testpq.cpp b/libpqpp/unittests/testpq.cpp
index 088910d..1905192 100644
--- a/libpqpp/unittests/testpq.cpp
+++ b/libpqpp/unittests/testpq.cpp
@@ -271,7 +271,7 @@ BOOST_AUTO_TEST_CASE( statementReuse )
 	BOOST_REQUIRE_EQUAL(pqconn->preparedStatements.size(), 1);
 	for (int y = 0; y < 4; y += 1) {
 		auto m1 = ro->modify("INSERT INTO test(id) VALUES(?)");
-		BOOST_REQUIRE_EQUAL(pqconn->preparedStatements.size(), 2);
+		BOOST_REQUIRE_EQUAL(pqconn->preparedStatements.size(), y == 0 ? 1 : 2);
 		for (int x = 0; x < 4; x += 1) {
 			m1->bindParamI(0, x);
 			m1->execute();