From 76ad0952419146874497d16d443d68cd28c1acb1 Mon Sep 17 00:00:00 2001
From: silverqx <silver.zachara@gmail.com>
Date: Tue, 18 Jan 2022 11:07:57 +0100
Subject: [PATCH] added Concerns::ExplainQueries

It is not enabled because Qt sql driver doesn't support EXPLAIN queries.
---
 include/orm/concerns/explainqueries.hpp | 48 +++++++++++++++++++++++++
 include/orm/tiny/tinybuilder.hpp        | 11 ------
 src/orm/concerns/explainqueries.cpp     | 30 ++++++++++++++++
 3 files changed, 78 insertions(+), 11 deletions(-)
 create mode 100644 include/orm/concerns/explainqueries.hpp
 create mode 100644 src/orm/concerns/explainqueries.cpp

diff --git a/include/orm/concerns/explainqueries.hpp b/include/orm/concerns/explainqueries.hpp
new file mode 100644
index 000000000..a3745ac47
--- /dev/null
+++ b/include/orm/concerns/explainqueries.hpp
@@ -0,0 +1,48 @@
+#pragma once
+#ifndef ORM_CONCERNS_EXPLAINQUERIES_HPP
+#define ORM_CONCERNS_EXPLAINQUERIES_HPP
+
+#include "orm/macros/systemheader.hpp"
+TINY_SYSTEM_HEADER
+
+#include <QtSql/QSqlQuery>
+
+#include "orm/macros/commonnamespace.hpp"
+#include "orm/macros/export.hpp"
+
+TINYORM_BEGIN_COMMON_NAMESPACE
+
+namespace Orm
+{
+namespace Query
+{
+    class Builder;
+}
+    using QueryBuilder = Query::Builder;
+
+namespace Concerns
+{
+
+    /*! Counts the number of executed queries and the elapsed time of queries. */
+    class SHAREDLIB_EXPORT ExplainQueries
+    {
+    public:
+        /*! Default constructor. */
+        inline ExplainQueries() = default;
+        /*! Virtual destructor. */
+        inline virtual ~ExplainQueries() = default;
+
+        /*! Explains the query. */
+        QSqlQuery explain();
+
+    private:
+        /*! Dynamic cast *this to the QueryBuilder & derived type. */
+        QueryBuilder &builder();
+    };
+
+} // namespace Concerns
+} // namespace Orm
+
+TINYORM_END_COMMON_NAMESPACE
+
+#endif // ORM_CONCERNS_EXPLAINQUERIES_HPP
diff --git a/include/orm/tiny/tinybuilder.hpp b/include/orm/tiny/tinybuilder.hpp
index a087d602a..b7f34fd16 100644
--- a/include/orm/tiny/tinybuilder.hpp
+++ b/include/orm/tiny/tinybuilder.hpp
@@ -163,9 +163,6 @@ namespace Orm::Tiny
         // FUTURE add Query Scopes feature silverqx
 //        { return $this->applyScopes()->getQuery(); }
 
-        /*! Explains the query. */
-//        QSqlQuery explain() const;
-
         /*! Qualify the given column name by the model's table. */
         inline QString qualifyColumn(const QString &column) const;
 
@@ -717,14 +714,6 @@ namespace Orm::Tiny
         return m_model.qualifyColumn(column);
     }
 
-    // BUG Qt sql driver does not support to call EXPLAIN as a prepared statement silverqx
-//    template<typename Model>
-//    QSqlQuery Builder<Model>::explain() const
-//    {
-//        return getConnection().select(QStringLiteral("EXPLAIN %1").arg(toSql()),
-//                                      getBindings());
-//    }
-
     template<typename Model>
     QVector<WithItem>
     Builder<Model>::parseWithRelations(const QVector<WithItem> &relations)
diff --git a/src/orm/concerns/explainqueries.cpp b/src/orm/concerns/explainqueries.cpp
new file mode 100644
index 000000000..b30eb986d
--- /dev/null
+++ b/src/orm/concerns/explainqueries.cpp
@@ -0,0 +1,30 @@
+#include "orm/concerns/explainqueries.hpp"
+
+#include "orm/databaseconnection.hpp"
+#include "orm/query/querybuilder.hpp"
+
+TINYORM_BEGIN_COMMON_NAMESPACE
+
+namespace Orm::Concerns
+{
+
+/* public */
+
+// BUG Qt sql driver does not support to call EXPLAIN as a prepared statement, look at enum StatementType and QSqlDriver::sqlStatement in qsqldriver.h/cpp, also don't forget to add proxies when Qt will support EXPLAIN queries silverqx
+QSqlQuery ExplainQueries::explain()
+{
+    return builder().getConnection().select(
+                QStringLiteral("EXPLAIN %1").arg(builder().toSql()),
+                builder().getBindings());
+}
+
+/* private */
+
+QueryBuilder &ExplainQueries::builder()
+{
+    return dynamic_cast<QueryBuilder &>(*this);
+}
+
+} // namespace Orm::Concerns
+
+TINYORM_END_COMMON_NAMESPACE