@Christian Ehrlicher you beat me to the punch. If you dump out the value (not the size) you will see the QVariant is a of type QString not QByteArray
const auto value = query.value(0); qDebug() << "value = " << value; auto tmp = QVariant( value.toByteArray() ); qDebug() << "tmp = " << tmp; value = QVariant(QString, "v10I-F½L\u009C{░?x\u009B)δ\u001EG#?????fóu??H") tmp = QVariant(QByteArray, "v10I-F\xC2\xABL\xC2\x9C{\xC2\xB0\xEF\xBF\xBDx\xC2\x9B)\xC3\xAB\x1EG#\xDE\xA6\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD\xEF\xBF\xBD""f\xC2\xA2u\xEF\xBF\xBD\xEF\xBF\xBD\xC4\xA6") This is the root cause of the problem. Ive hit this before, the query.value function should return a QByteArray type of QVariant, not a QString type when the column type is of type blob. auto record = db.record( "test" ); qDebug() << "record =" << record; returns the correct record type record = QSqlRecord(1) 0: QSqlField("value", QByteArray, tableName: "test", required: yes, generated: yes, autoValue: false, readOnly: false) "" Whats interesting, is in my qsql_sqlite.cpp (the driver for the sql database, sqlite3_column_decltype16 returns "BLOB" but sqlite3_column_type returns SQLITE_TEXT in the init columns function, to determine which Qt type to use, it first gets the string name of the column, if empty then use sqlite3_column_type otherwise it uses qGetColumnType So the Record is correct, but the return type is of QString not QByteArray Scott -----Original Message----- From: Interest <interest-boun...@qt-project.org> On Behalf Of Christian Ehrlicher Sent: Monday, November 28, 2022 10:41 AM To: Yauheni Pervenenka <yauheni.pervene...@viber.com>; interest@qt-project.org Subject: Re: [Interest] Qt Sql BLOB data converting Am 28.11.2022 um 19:16 schrieb Yauheni Pervenenka via Interest: > Thiago, hello, thanks for your reply, sorry have no instructions for > create and insert, but have data base with one value which can't be > parsed correct(db is cut to one value for provide example) > > https://bugreports.qt.io/browse/QTBUG-108992 > Your database looks strange to me - even though your column type according to the schema is BLOB: sqlite> .schema CREATE TABLE IF NOT EXISTS "test" ( "value" BLOB NOT NULL ); the return value of sqlite3_column_type() is SQLITE_TEXT (3). Therefore the return value is treated as string and the data is screwed up. If I change the return value to SQLITE_BLOB (4) in the debugger, all is correct: qDebug() << value.toByteArray().toHex(); --> "763130492d46ab4c9c7bb0e9789b29c3ab1e4723dea6c8e5d2f9b266a275e1fbe4a6" Christian _______________________________________________ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest _______________________________________________ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest