#4600 #4587 Fixed very slow loading of data in tables with foreign keys.

pawelsalawa · Dec 2, 2022 · 91552b0 · 91552b0
1 parent 869068b
commit 91552b0
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diff --git a/ChangeLog.md b/ChangeLog.md
@@ -2,6 +2,7 @@
 
 ### 3.4.1
 - CHANGE: #4585 SQLite updated to 3.40.0 (except for SQLCipher, which has latest version 3.39.2).
+- BUGFIX: #4600 #4587 Fixed very slow loading of data in tables with foreign keys.
 - BUGFIX: #4549 Query executor column aliases do not need wrapping anymore, because parser in 3.4.0 does not strip wrapped aliases anymore.
 - BUGFIX: #4219 Removed duplicated UI config entries generated by Printing plugin.
 - BUGFIX: #4563 Installer now runs the application at final step as a regular user even if running as root.

diff --git a/SQLiteStudio3/guiSQLiteStudio/datagrid/fkcombobox.cpp b/SQLiteStudio3/guiSQLiteStudio/datagrid/fkcombobox.cpp
@@ -331,3 +331,15 @@ QString FkComboBox::getSql() const
 
     return getSqlForFkEditor(comboModel->getDb(), columnModel, sourceValue);
 }
+
+qlonglong FkComboBox::getRowCountForFkEditor(Db* db, const QString& query, bool* isError)
+{
+    static_qstring(tpl, "SELECT count(*) FROM (%1)");
+
+    QString sql = tpl.arg(query);
+    SqlQueryPtr result = db->exec(sql);
+    if (isError)
+        *isError = result->isError();
+
+    return result->getSingleCell().toLongLong();
+}
diff --git a/SQLiteStudio3/guiSQLiteStudio/datagrid/fkcombobox.h b/SQLiteStudio3/guiSQLiteStudio/datagrid/fkcombobox.h
@@ -16,6 +16,7 @@ class FkComboBox : public QComboBox
         FkComboBox(QWidget *parent, int dropDownViewMinWidth = -1);
 
         static QString getSqlForFkEditor(Db* db, SqlQueryModelColumn* columnModel, const QVariant& currentValue);
+        static qlonglong getRowCountForFkEditor(Db* db, const QString& query, bool* isError);
 
         static const qlonglong MAX_ROWS_FOR_FK = 10000L;
         static const int FK_CELL_LENGTH_LIMIT = 30;

diff --git a/SQLiteStudio3/guiSQLiteStudio/datagrid/sqlqueryitemdelegate.cpp b/SQLiteStudio3/guiSQLiteStudio/datagrid/sqlqueryitemdelegate.cpp
@@ -304,24 +304,12 @@ QString SqlQueryItemDelegate::getSqlForFkEditor(SqlQueryItem* item) const
                 );
 }
 
-qlonglong SqlQueryItemDelegate::getRowCountForFkEditor(Db* db, const QString& query, bool* isError) const
-{
-    static_qstring(tpl, "SELECT count(*) FROM (%1)");
-
-    QString sql = tpl.arg(query);
-    SqlQueryPtr result = db->exec(sql);
-    if (isError)
-        *isError = result->isError();
-
-    return result->getSingleCell().toLongLong();
-}
-
 QWidget* SqlQueryItemDelegate::getFkEditor(SqlQueryItem* item, QWidget* parent, const SqlQueryModel* model) const
 {
     Db* db = model->getDb();
     bool countingError = false;
     QString sql = FkComboBox::getSqlForFkEditor(db, item->getColumn(), item->getValue());
-    qlonglong rowCount = getRowCountForFkEditor(db, sql, &countingError);
+    qlonglong rowCount = FkComboBox::getRowCountForFkEditor(db, sql, &countingError);
     if (rowCount > FkComboBox::MAX_ROWS_FOR_FK)
     {
         notifyWarn(tr("Foreign key for column %2 has more than %1 possible values. It's too much to display in drop down list. You need to edit value manually.")

diff --git a/SQLiteStudio3/guiSQLiteStudio/formview.cpp b/SQLiteStudio3/guiSQLiteStudio/formview.cpp
@@ -1,5 +1,6 @@
 #include "formview.h"
 #include "common/unused.h"
+#include "datagrid/fkcombobox.h"
 #include "datagrid/sqlquerymodel.h"
 #include "datagrid/sqlqueryview.h"
 #include "multieditor/multieditorfk.h"
@@ -64,15 +65,15 @@ void FormView::setModel(SqlQueryModel* value)
 
 void FormView::load()
 {
-    reloadInternal();
-    dataMapper->toFirst();
+    shouldReload = true;
+    indexForReload = 0;
 }
 
 void FormView::reload()
 {
-    int idx = dataMapper->getCurrentIndex();
+    shouldReload = true;
+    indexForReload = dataMapper->getCurrentIndex();
     reloadInternal();
-    dataMapper->setCurrentIndex(idx);
 }
 
 void FormView::focusFirstEditor()
@@ -85,6 +86,11 @@ void FormView::focusFirstEditor()
 
 void FormView::reloadInternal()
 {
+    if (!shouldReload)
+        return;
+
+    shouldReload = false;
+
     // Cleanup
     dataMapper->clearMapping();
     for (QWidget*& widget : widgets)
@@ -131,7 +137,21 @@ MultiEditor* FormView::addColumn(int colIdx, SqlQueryModelColumn* column)
 
     // MultiEditor editors
     if (!column->getFkConstraints().isEmpty())
-        multiEditor->enableFk(model->getDb(), column);
+    {
+        Db* db = model->getDb();
+        QString sql = FkComboBox::getSqlForFkEditor(db, column, QVariant());
+        bool countingError = false;
+        qlonglong rowCount = FkComboBox::getRowCountForFkEditor(db, sql, &countingError);
+        if (!countingError && rowCount <= FkComboBox::MAX_ROWS_FOR_FK)
+            multiEditor->enableFk(db, column);
+        else
+        {
+            qDebug() << "FkCombo excluded from FormView for column" << column->column << "due to"
+                     << (countingError ?
+                             "error with row counting query" :
+                             "too many rows in the FK table: " + QString::number(rowCount));
+        }
+    }
 
     multiEditor->setDataType(column->dataType);
 
@@ -275,3 +295,10 @@ QToolBar* FormView::getToolBar(int toolbar) const
     UNUSED(toolbar);
     return nullptr;
 }
+
+void FormView::showEvent(QShowEvent* event)
+{
+    UNUSED(event);
+    reloadInternal();
+    dataMapper->setCurrentIndex(indexForReload);
+}
diff --git a/SQLiteStudio3/guiSQLiteStudio/formview.h b/SQLiteStudio3/guiSQLiteStudio/formview.h
@@ -63,6 +63,7 @@ class GUI_API_EXPORT FormView : public QScrollArea, public ExtActionContainer
         void createActions();
         void setupDefShortcuts();
         QToolBar* getToolBar(int toolbar) const;
+        void showEvent(QShowEvent* event);
 
     private:
         void reloadInternal();
@@ -83,6 +84,8 @@ class GUI_API_EXPORT FormView : public QScrollArea, public ExtActionContainer
         QList<bool> readOnly;
         bool valueModified = false;
         bool currentIndexUpdating = false;
+        bool shouldReload = false;
+        int indexForReload = 0;
 
     private slots:
         void dataLoaded(bool successful);