From 4ab84b086d4af4f824f5f231cf7d97121ca23470 Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Fri, 24 Aug 2018 10:02:15 +0100
Subject: Don't rely on libdbppcore's columns

Also reduce risk of needing to resize at all by getting the octet size
---
 libodbcpp/odbc-modifycommand.cpp |  2 +-
 libodbcpp/odbc-selectcommand.cpp | 25 +++++++++++++++----------
 libodbcpp/odbc-selectcommand.h   |  3 +++
 libodbcpp/unittests/testodbc.cpp | 15 +++++++++++++++
 4 files changed, 34 insertions(+), 11 deletions(-)

(limited to 'libodbcpp')

diff --git a/libodbcpp/odbc-modifycommand.cpp b/libodbcpp/odbc-modifycommand.cpp
index 0eeca01..60bb7c4 100644
--- a/libodbcpp/odbc-modifycommand.cpp
+++ b/libodbcpp/odbc-modifycommand.cpp
@@ -15,7 +15,7 @@ ODBC::ModifyCommand::~ModifyCommand()
 unsigned int
 ODBC::ModifyCommand::execute(bool anc)
 {
-	RETCODE rc = SQLExecute(hStmt); 
+	RETCODE rc = SQLExecute(hStmt);
 	if (!SQL_SUCCEEDED(rc)) {
 		if (rc != SQL_NO_DATA || !anc) {
 			throw Error(rc, SQL_HANDLE_STMT, hStmt);
diff --git a/libodbcpp/odbc-selectcommand.cpp b/libodbcpp/odbc-selectcommand.cpp
index 6b28a32..5e26053 100644
--- a/libodbcpp/odbc-selectcommand.cpp
+++ b/libodbcpp/odbc-selectcommand.cpp
@@ -16,7 +16,7 @@ ODBC::SelectCommand::SelectCommand(const Connection & c, const std::string & s)
 
 ODBC::SelectCommand::~SelectCommand()
 {
-	if (!columns->empty()) {
+	if (columnCount()) {
 		SQLCloseCursor(hStmt);
 	}
 }
@@ -30,7 +30,7 @@ ODBC::SelectCommand::fetch()
 bool
 ODBC::SelectCommand::fetch(SQLSMALLINT orientation, SQLLEN offset)
 {
-	if (columns->empty()) {
+	if (!columnCount()) {
 		execute();
 	}
 	RETCODE rc = SQLFetchScroll(hStmt, orientation, offset);
@@ -42,22 +42,20 @@ ODBC::SelectCommand::fetch(SQLSMALLINT orientation, SQLLEN offset)
 				RETCODE diagrc = SQLGetDiagRec(SQL_HANDLE_STMT, hStmt, 1, sqlstatus, NULL, NULL, 0, NULL);
 				if (SQL_SUCCEEDED(diagrc)) {
 					if (!strncmp((const char*)sqlstatus, "01004", 5)) {
-						for (Columns::iterator i = columns->begin(); i != columns->end(); ++i) {
-							std::dynamic_pointer_cast<Column>(*i)->resize();
+						for (const auto & c : largeColumns) {
+							c->resize();
 						}
 						return fetch(SQL_FETCH_RELATIVE, 0);
 					}
-				}
-				if (rc != SQL_SUCCESS_WITH_INFO) {
-					throw Error(rc, SQL_HANDLE_STMT, hStmt);
+					fprintf(stderr, "truncation\n");
 				}
 			}
 			// fall-through
 		case SQL_SUCCESS:
 			{
 				bool resized = false;
-				for (Columns::iterator i = columns->begin(); i != columns->end(); ++i) {
-					resized |= std::dynamic_pointer_cast<Column>(*i)->resize();
+				for (const auto & c : largeColumns) {
+					resized |= c->resize();
 				}
 				if (resized) {
 					return fetch(SQL_FETCH_RELATIVE, 0);
@@ -130,7 +128,14 @@ ODBC::SelectCommand::execute()
 			case SQL_UNKNOWN_TYPE:
 				throw DB::ColumnTypeNotSupported();
 			default:
-				ncol = insertColumn(std::make_shared<CharArrayColumn>(this, colName, col, bindSize));
+				SQLLEN octetSize = 0;
+				if (!SQL_SUCCEEDED(rc = SQLColAttribute(hStmt, sqlcol, SQL_DESC_OCTET_LENGTH, NULL, 0, NULL, &octetSize))) {
+					throw Error(rc, SQL_HANDLE_STMT, hStmt);
+				}
+				bindSize = octetSize;
+				auto lc = std::make_shared<CharArrayColumn>(this, colName, col, bindSize);
+				ncol = insertColumn(lc);
+				largeColumns.insert(lc);
 				break;
 		};
 		std::dynamic_pointer_cast<Column>(ncol)->bind();
diff --git a/libodbcpp/odbc-selectcommand.h b/libodbcpp/odbc-selectcommand.h
index 2d4311a..1c71d57 100644
--- a/libodbcpp/odbc-selectcommand.h
+++ b/libodbcpp/odbc-selectcommand.h
@@ -15,6 +15,9 @@ namespace ODBC {
 
 		private:
 			bool				fetch(SQLSMALLINT orientation = SQL_FETCH_NEXT, SQLLEN offset = 0);
+			typedef std::shared_ptr<Column> ColumnPtr;
+			typedef std::set<ColumnPtr> Columns;
+			Columns largeColumns;
 	};
 }
 
diff --git a/libodbcpp/unittests/testodbc.cpp b/libodbcpp/unittests/testodbc.cpp
index bb6fd97..9a810c7 100644
--- a/libodbcpp/unittests/testodbc.cpp
+++ b/libodbcpp/unittests/testodbc.cpp
@@ -4,6 +4,7 @@
 #include <definedDirs.h>
 #include <modifycommand.h>
 #include <selectcommand.h>
+#include <selectcommandUtil.impl.h>
 #include <column.h>
 #include <error.h>
 #include <odbc-mock.h>
@@ -90,5 +91,19 @@ BOOST_AUTO_TEST_CASE( bindAndSelectOther )
 	BOOST_REQUIRE_EQUAL(1, rows);
 }
 
+BOOST_AUTO_TEST_CASE( multibyte )
+{
+	auto ro = DB::MockDatabase::openConnectionTo("odbcmock");
+
+	auto select = ro->select("SELECT LPAD('', n, '£'), n FROM GENERATE_SERIES(1, 50000, 200) n");
+	select->execute();
+	int rows = 0;
+	for (const auto [s, n] : select->as<std::string, int64_t>()) {
+		BOOST_CHECK_EQUAL(s.length(), n * 2);
+		rows += 1;
+	}
+	BOOST_REQUIRE_EQUAL(250, rows);
+}
+
 BOOST_AUTO_TEST_SUITE_END();
 
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