QSqlQuery, addBindValue, LargeBlob problem?
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I am constructing a call to a stored procedure, one of the parameters was previously a BLOB, I've changed it now to a LONGBLOB and now there seems to be a problem.
C++ Code:
QSqlQuery queryBlock; queryBlock.prepare("SELECT addBlock(?,?,?,?,?);"); qdbg() << "muintDatasetID: " << muintDatasetID; qdbg() << " strFilename: " << strFilename; qdbg() << " muint64Block: " << muint64Block; qdbg() << " bytaryChunk: " << bytaryChunk.length(); qdbg() << " uint8Checksum: " << uint8Checksum; queryBlock.addBindValue(muintDatasetID); queryBlock.addBindValue(strFilename); queryBlock.addBindValue(muint64Block); queryBlock.addBindValue(bytaryChunk, QSql::Binary); queryBlock.addBindValue(uint8Checksum); if ( Trainer::queryDB(queryBlock) == true )My stored procedure:
CREATE DEFINER=`root`@`localhost` FUNCTION `addBlock`( `_biDataset` BIGINT, `_txtFilename` TEXT, `_intBlockNo` INT, `_binChunk` LONGBLOB, `_intChecksum` INT ) RETURNS bigint(20) LANGUAGE SQL DETERMINISTIC CONTAINS SQL SQL SECURITY DEFINER COMMENT 'Adds a single data block' exitProc:BEGIN #Function: addBlock #Parameters: _biDataset Optional, Dataset In/Out number # _txtFilename File name of RDF dataset # _intBlockNo Block number (base 0) # _binChunk Large Binary Blob of Data # _intChecksum 8 bit CRC #Notes: Creates single record of data block #History: 2021/05/19 Written by Simon Platten #Validate parameters IF _txtFilename IS NULL OR _intBlockNo IS NULL OR _binChunk IS NULL OR _intChecksum IS NULL THEN #No, abort! RETURN -1; END IF; IF _biDataset IS NULL THEN #Look up the dataset id SELECT `biPK` INTO _biDataset FROM datasets WHERE txtFilename=_txtFilename; END IF; #Was dataset located? IF _biDataset IS NULL THEN #No, abort! RETURN -2; END IF; #Insert new record INSERT INTO `rdf` ( `biDataset`, `intBlockNo`, `intChecksum`, `binChunk` ) VALUES ( _biDataset, _intBlockNo, _intChecksum, _binChunk ); RETURN LAST_INSERT_ID(); ENDOutput to console:
muintDatasetID: 1 strFilename: 20211004_11h42_LabTest_tvg5000_0.rdf muint64Block: 0 bytaryChunk: 34390236 uint8Checksum: 18This code previously worked when I was dealing with a BLOB, now I've changed the stored procedure and table types from BLOB to LONGBLOB it errors, with no sensible error message I can post. What could the problem?
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@SPlatten Are you certain that both the DB you are connected to and the driver/connector support such construct? My gut feeling would be that id DB supports the driver has a problem.
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@artwaw , is there anyway I can find out? I'm using HeidiSQL to review the database and that looks ok.
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@SPlatten said in QSqlQuery, addBindValue, LargeBlob problem?:
is there anyway I can find out
Documentation to both, I suppose?
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@artwaw, MariaDB certainly supports LARGEBLOB, no errors in HeidiSQL, so it could be the SQL driver I guess...
@SPlatten How large is the blob in your case? I think I remember reading the advice about large blobs in MariaDB that one should be careful since it is easy to run of memory in the stack or something.
In other words: might be it is worth to change toQSqlQuery *queryBlock = new QSqlQuery()etc. Again, one of the possibilities, I am not certain what fails there.For more information please re-read.
Kind Regards,
Artur -
@SPlatten How large is the blob in your case? I think I remember reading the advice about large blobs in MariaDB that one should be careful since it is easy to run of memory in the stack or something.
In other words: might be it is worth to change toQSqlQuery *queryBlock = new QSqlQuery()etc. Again, one of the possibilities, I am not certain what fails there. -
@SPlatten How large is the blob in your case? I think I remember reading the advice about large blobs in MariaDB that one should be careful since it is easy to run of memory in the stack or something.
In other words: might be it is worth to change toQSqlQuery *queryBlock = new QSqlQuery()etc. Again, one of the possibilities, I am not certain what fails there.@artwaw , the message that appears in dialog:
Lost connection to MySQL server during query QMYSQL3: Unable to execute statementAnd from the event viewer Application:
Aborted connection 3 to db: 'training' host: 'localhost' (Got a packet bigger than 'max_allowed_packet' bytes)However in my code I check the array size for < ULONG_MAX which is 4GB before I try to submit it.
Kind Regards,
Sy -
@artwaw , the message that appears in dialog:
Lost connection to MySQL server during query QMYSQL3: Unable to execute statementAnd from the event viewer Application:
Aborted connection 3 to db: 'training' host: 'localhost' (Got a packet bigger than 'max_allowed_packet' bytes)However in my code I check the array size for < ULONG_MAX which is 4GB before I try to submit it.
@SPlatten said in QSqlQuery, addBindValue, LargeBlob problem?:
max_allowed_packet
So hard to search for
HeideSQL max_allowed_packet? The first hit gives you the config option...Qt Online Installer direct download: https://download.qt.io/official_releases/online_installers/
Visit the Qt Academy at https://academy.qt.io/catalog -
@artwaw , the message that appears in dialog:
Lost connection to MySQL server during query QMYSQL3: Unable to execute statementAnd from the event viewer Application:
Aborted connection 3 to db: 'training' host: 'localhost' (Got a packet bigger than 'max_allowed_packet' bytes)However in my code I check the array size for < ULONG_MAX which is 4GB before I try to submit it.
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@SPlatten said in QSqlQuery, addBindValue, LargeBlob problem?:
max_allowed_packet
So hard to search for
HeideSQL max_allowed_packet? The first hit gives you the config option...@Christian-Ehrlicher , found this https://docs.oracle.com/cd/E19509-01/820-6323/gicxk/index.html, modified my.ini, your so pissy, where you abused as a child?
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@SPlatten said in QSqlQuery, addBindValue, LargeBlob problem?:
'max_allowed_packet' bytes
Configuration of the server doesn't permit the size you send.
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@Christian-Ehrlicher , found this https://docs.oracle.com/cd/E19509-01/820-6323/gicxk/index.html, modified my.ini, your so pissy, where you abused as a child?
@SPlatten said in QSqlQuery, addBindValue, LargeBlob problem?:
your so pissy
Because you're to lazy (or whatever) to search for the simplest things before you write a new question which every kid could resolve in less than a minute...
Qt Online Installer direct download: https://download.qt.io/official_releases/online_installers/
Visit the Qt Academy at https://academy.qt.io/catalog -
@SPlatten said in QSqlQuery, addBindValue, LargeBlob problem?:
your so pissy
Because you're to lazy (or whatever) to search for the simplest things before you write a new question which every kid could resolve in less than a minute...
@Christian-Ehrlicher , this forum is a resource full of knowledgeable people, just like a Google search is also a resource, how and what I choose to do is my choice.
