From bbffe078612e5cbf6a893ef4f2df9575197175fc Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Thu, 17 Jun 2021 19:54:11 +0100
Subject: Fix MySQLRecordSet seek/fetch behaviour

---
 lib/input/mysqlRecordSet.cpp | 7 +++++--
 lib/input/mysqlRecordSet.h   | 1 +
 2 files changed, 6 insertions(+), 2 deletions(-)

(limited to 'lib/input')

diff --git a/lib/input/mysqlRecordSet.cpp b/lib/input/mysqlRecordSet.cpp
index 22b7214..71c5148 100644
--- a/lib/input/mysqlRecordSet.cpp
+++ b/lib/input/mysqlRecordSet.cpp
@@ -72,7 +72,6 @@ namespace MyGrate::Input {
 		verify<MySQLErr>(!mysql_stmt_bind_result(stmt.get(), fields.data()), "Store result error", stmt->mysql);
 		verify<MySQLErr>(!mysql_stmt_store_result(stmt.get()), "Store result error", stmt->mysql);
 		stmtres = {stmt.get(), mysql_stmt_free_result};
-		verify<MySQLErr>(!mysql_stmt_fetch(stmt.get()), "Fetch", stmt->mysql);
 	}
 
 	std::size_t
@@ -90,7 +89,11 @@ namespace MyGrate::Input {
 	DbValue
 	MySQLRecordSet::at(std::size_t row, std::size_t col) const
 	{
-		mysql_stmt_data_seek(stmt.get(), row);
+		if (currentRow != row) {
+			mysql_stmt_data_seek(stmt.get(), row);
+			verify<MySQLErr>(!mysql_stmt_fetch(stmt.get()), "Fetch", stmt->mysql);
+			currentRow = row;
+		}
 		if (extras[col]->null) {
 			return nullptr;
 		}
diff --git a/lib/input/mysqlRecordSet.h b/lib/input/mysqlRecordSet.h
index 849a653..aec733e 100644
--- a/lib/input/mysqlRecordSet.h
+++ b/lib/input/mysqlRecordSet.h
@@ -31,6 +31,7 @@ namespace MyGrate::Input {
 		StmtResPtr stmtres;
 		std::vector<MYSQL_BIND> fields;
 		std::vector<ResultDataPtr> extras;
+		mutable std::size_t currentRow {static_cast<size_t>(-1)};
 	};
 }
 
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