3 files changed, 53 insertions, 8 deletions

diff --git a/src/sql/kernel/qsqldatabase.cpp b/src/sql/kernel/qsqldatabase.cpp
index 2c7b4b83db..d63a9e59a8 100644
--- a/src/sql/kernel/qsqldatabase.cpp
+++ b/src/sql/kernel/qsqldatabase.cpp
@@ -1088,6 +1088,11 @@ QStringList QSqlDatabase::tables(QSql::TableType type) const
     Returns the primary index for table \a tablename. If no primary
     index exists, an empty QSqlIndex is returned.
 
+    \note Some drivers, such as the \l {QPSQL Case Sensitivity}{QPSQL}
+    driver, may may require you to pass \a tablename in lower case if
+    the table was not quoted when created. See the
+    \l{sql-driver.html}{Qt SQL driver} documentation for more information.
+
     \sa tables(), record()
 */
 
@@ -1102,6 +1107,11 @@ QSqlIndex QSqlDatabase::primaryIndex(const QString& tablename) const
     the table (or view) called \a tablename. The order in which the
     fields appear in the record is undefined. If no such table (or
     view) exists, an empty record is returned.
+
+    \note Some drivers, such as the \l {QPSQL Case Sensitivity}{QPSQL}
+    driver, may may require you to pass \a tablename in lower case if
+    the table was not quoted when created. See the
+    \l{sql-driver.html}{Qt SQL driver} documentation for more information.
 */
 
 QSqlRecord QSqlDatabase::record(const QString& tablename) const
@@ -1380,6 +1390,40 @@ QSqlDatabase QSqlDatabase::cloneDatabase(const QSqlDatabase &other, const QStrin
 }
 
 /*!
+    \since 5.13
+    \overload
+
+    Clones the database connection \a other and stores it as \a
+    connectionName. All the settings from the original database, e.g.
+    databaseName(), hostName(), etc., are copied across. Does nothing
+    if \a other is an invalid database. Returns the newly created
+    database connection.
+
+    \note The new connection has not been opened. Before using the new
+    connection, you must call open().
+
+    This overload is useful when cloning the database in another thread to the
+    one that is used by the database represented by \a other.
+*/
+
+QSqlDatabase QSqlDatabase::cloneDatabase(const QString &other, const QString &connectionName)
+{
+    const QConnectionDict *dict = dbDict();
+    Q_ASSERT(dict);
+
+    dict->lock.lockForRead();
+    QSqlDatabase otherDb = dict->value(other);
+    dict->lock.unlock();
+    if (!otherDb.isValid())
+        return QSqlDatabase();
+
+    QSqlDatabase db(otherDb.driverName());
+    db.d->copy(otherDb.d);
+    QSqlDatabasePrivate::addDatabase(db, connectionName);
+    return db;
+}
+
+/*!
     \since 4.4
 
     Returns the connection name, which may be empty.  \note The
diff --git a/src/sql/kernel/qsqldatabase.h b/src/sql/kernel/qsqldatabase.h
index 3aadab9b2f..f233c72c19 100644
--- a/src/sql/kernel/qsqldatabase.h
+++ b/src/sql/kernel/qsqldatabase.h
@@ -118,6 +118,7 @@ public:
     static QSqlDatabase addDatabase(QSqlDriver* driver,
                                  const QString& connectionName = QLatin1String(defaultConnection));
     static QSqlDatabase cloneDatabase(const QSqlDatabase &other, const QString& connectionName);
+    static QSqlDatabase cloneDatabase(const QString &other, const QString& connectionName);
     static QSqlDatabase database(const QString& connectionName = QLatin1String(defaultConnection),
                                  bool open = true);
     static void removeDatabase(const QString& connectionName);
diff --git a/src/sql/kernel/qsqldriver.cpp b/src/sql/kernel/qsqldriver.cpp
index 8c6ae382f6..7f7b81b05b 100644
--- a/src/sql/kernel/qsqldriver.cpp
+++ b/src/sql/kernel/qsqldriver.cpp
@@ -488,6 +488,8 @@ QString QSqlDriver::stripDelimiters(const QString &identifier, IdentifierType ty
 QString QSqlDriver::sqlStatement(StatementType type, const QString &tableName,
                                  const QSqlRecord &rec, bool preparedStatement) const
 {
+    const auto tableNameString = tableName.isEmpty() ? QString()
+                                    : prepareIdentifier(tableName, QSqlDriver::TableName, this);
     int i;
     QString s;
     s.reserve(128);
@@ -500,13 +502,12 @@ QString QSqlDriver::sqlStatement(StatementType type, const QString &tableName,
         if (s.isEmpty())
             return s;
         s.chop(2);
-        s.prepend(QLatin1String("SELECT ")).append(QLatin1String(" FROM ")).append(tableName);
+        s = QLatin1String("SELECT ") + s + QLatin1String(" FROM ") + tableNameString;
         break;
     case WhereStatement:
     {
-        const QString tableNamePrefix = tableName.isEmpty()
-            ? QString()
-            : prepareIdentifier(tableName, QSqlDriver::TableName, this) + QLatin1Char('.');
+        const QString tableNamePrefix = tableNameString.isEmpty()
+                                            ? QString() : tableNameString + QLatin1Char('.');
         for (int i = 0; i < rec.count(); ++i) {
             if (!rec.isGenerated(i))
                 continue;
@@ -523,8 +524,7 @@ QString QSqlDriver::sqlStatement(StatementType type, const QString &tableName,
         break;
     }
     case UpdateStatement:
-        s.append(QLatin1String("UPDATE ")).append(tableName).append(
-                 QLatin1String(" SET "));
+        s = s + QLatin1String("UPDATE ") + tableNameString + QLatin1String(" SET ");
         for (i = 0; i < rec.count(); ++i) {
             if (!rec.isGenerated(i))
                 continue;
@@ -541,10 +541,10 @@ QString QSqlDriver::sqlStatement(StatementType type, const QString &tableName,
             s.clear();
         break;
     case DeleteStatement:
-        s.append(QLatin1String("DELETE FROM ")).append(tableName);
+        s = s + QLatin1String("DELETE FROM ") + tableNameString;
         break;
     case InsertStatement: {
-        s.append(QLatin1String("INSERT INTO ")).append(tableName).append(QLatin1String(" ("));
+        s = s + QLatin1String("INSERT INTO ") + tableNameString + QLatin1String(" (");
         QString vals;
         for (i = 0; i < rec.count(); ++i) {
             if (!rec.isGenerated(i))