From: APTX <marek321@gmail.com>
Date: Sat, 14 Jul 2012 01:10:22 +0000 (+0200)
Subject: A way of dynamically preparing statements only when needed + test use
X-Git-Url: https://gitweb.aptx.org/?a=commitdiff_plain;h=df9843d89c01faebc8a87501f75be057fb065a87;p=localmylist.git

A way of dynamically preparing statements only when needed + test use
---

diff --git a/localmylist/database.cpp b/localmylist/database.cpp
index 5257633..d095f70 100644
--- a/localmylist/database.cpp
+++ b/localmylist/database.cpp
@@ -127,6 +127,8 @@ struct DatabaseInternal
 {
 	QSqlDatabase db;
 
+	QHash<const char *const, QSqlQuery> preparedQueries;
+
 	QSqlQuery getHostInfoQuery;
 	QSqlQuery isKnownFileQuery;
 
@@ -1318,6 +1320,33 @@ OpenFileData Database::readOpenFileData(QSqlQuery &q)
 	return data;
 }
 
+
+QSqlQuery &Database::prepare(const char *const sql)
+{
+	auto it = d->preparedQueries.find(sql);
+
+	if (it != d->preparedQueries.end())
+		return it.value();
+
+
+	QSqlQuery query(d->db);
+
+	if (!query.prepare(sql))
+	{
+		qDebug() << "SQL error: " << query.lastError().type();
+		qDebug() << "Message:   " << query.lastError().text();
+		qDebug() << "DB Message:" << query.lastError().databaseText();
+		qDebug() << "Query:     " << query.executedQuery();
+
+		if (query.lastError().type() == QSqlError::ConnectionError)
+			disconnect();
+	}
+
+	auto ite = d->preparedQueries.insert(sql, query);
+	return ite.value();
+}
+
+
 bool Database::exec(QSqlQuery &query)
 {
 	Q_ASSERT_X(d->thread == QThread::currentThread(), "threads", "DB used from different thread");
diff --git a/localmylist/database.h b/localmylist/database.h
index d56bca3..779e661 100644
--- a/localmylist/database.h
+++ b/localmylist/database.h
@@ -292,6 +292,7 @@ public:
 
 	QSqlDatabase connection() const;
 
+	QSqlQuery &prepare(const char *const sql);
 	bool exec(QSqlQuery &query);
 	bool exec(const QString &sql);
 
diff --git a/localmylist/mylistnode.cpp b/localmylist/mylistnode.cpp
index 1b36156..9f546f6 100644
--- a/localmylist/mylistnode.cpp
+++ b/localmylist/mylistnode.cpp
@@ -96,11 +96,14 @@ bool MyListNode::canFetchMore() const
 int MyListNode::fetchMore()
 {
 	qDebug() << "fetching some more for root";
-	QSqlQuery q(LocalMyList::instance()->database()->connection());
-
-	if (!q.exec("SELECT aid, title_romaji AS title, (SELECT COUNT(e.eid) FROM episode e WHERE e.aid = a.aid), rating, my_vote, (SELECT COUNT(DISTINCT f.eid) FROM episode e  JOIN file f ON (f.eid = e.eid)  WHERE e.aid = a.aid  AND f.my_watched IS NOT NULL) FROM anime a ORDER BY title ASC "
-				"LIMIT " + QString::number(LIMIT) + " "
-				"OFFSET " + QString::number(childCount())))
+	QSqlQuery &q = LocalMyList::instance()->database()->prepare(
+			"SELECT aid, title_romaji AS title, (SELECT COUNT(e.eid) FROM episode e WHERE e.aid = a.aid), rating, my_vote, (SELECT COUNT(DISTINCT f.eid) FROM episode e  JOIN file f ON (f.eid = e.eid)  WHERE e.aid = a.aid  AND f.my_watched IS NOT NULL) FROM anime a ORDER BY title ASC "
+			"LIMIT :limit "
+			"OFFSET :offset ");
+	q.bindValue(":limit", LIMIT);
+	q.bindValue(":offset", childCount());
+
+	if (!LocalMyList::instance()->database()->exec(q))
 		return 0;
 
 	while (q.next())