SQLITE_DQS Compile Option

[figaro-smartotum]

Just a note for other people that could incurr in the same issue performing a similar task.
I am trying to perform a pretty challenging task. I want to use this ORM on an STM32 microcontroller having just a few of kBytes of RAM and less than 2MB of free program memory, using LittleFS as filesystem.

I implemented a dedicated VFS for SQLite and registered sqlite3_vfs_register.
Since many other compile-time defines are involved in order to reduce the code size, I was also using SQLITE_DQS=0 as recommended in the SQLite doc.

The recommended setting is 0, meaning that double-quoted strings are disallowed in all contexts. However, the default setting is 3 for maximum compatibility with legacy applications.

But it turns that sqlite_orm requires the SQLITE_DQS=3 compile definition, since it heavily relies on double-quoted strings.

It is wonderful to be able to use such abstraction level on a really minimal hardware like an STM32 microcontroller.
Many thanks to all

[fnc12]

hi. It is a very interesting case. As I understood you need to make sqlite_orm serializer to replace double quotes with single quotes to make your code working on your controller. Is it right?

[figaro-smartotum]

I was able to getting SQLite ORM properly working by overriding the suggested define from 0 to 3, without any kind of additional problems (for now 😅). Anyway since the usage of DQS is not suggested from the official documentation, it could make sense to consider how to take this into account in the future . . Il mer 10 apr 2024, 06:38 Yevgeniy Zakharov ***@***.***> ha scritto:

…

hi. It is a very interesting case. As I understood you need to make sqlite_orm serializer to replace double quotes with single quotes to make your code working on your controller. Is it right? — Reply to this email directly, view it on GitHub <#1269 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A6TA2CSZ26OLCSNC72TUOJLY4S65LAVCNFSM6AAAAABF7JK25OVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDANBWGUZDKNZXG4> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[trueqbit]

@figaro-smartotum Nice to see a Rossini fan 😏

It's not clear to me how sqlite_orm "heavily relies on double-quoted strings".
sqlite_orm sets all identifiers correctly in double quotation marks and sets string literals correctly in single quotation marks, unless there is an error.

Can you show how and where you encounter the problem?

[figaro-smartotum]

The query for checking if the table exists, when performing the sync_schema is failing if DQS == 0.

[trueqbit]

sqlite_orm properly quotes and escapes the table name.

[figaro-smartotum]

(28) double-quoted string literal: "table"
warning reported when executing

"SELECT COUNT(*) FROM sqlite_master WHERE type = \"table\" AND name = '<<tablename>>'"

The function where the warning is triggered is
bool table_exists(sqlite3* db, const std::string& tableName) const

In this context ŧable is a string literal, so sqlite is expecting a single quote.

[trueqbit]

Did you actually look at the link I mentioned above? You didn't mention that you are using sqlite_orm v1.8.2 on master. This issue was fixed more than a year ago in the dev branch, which was part of PR #1169.

[fnc12]

@figaro-smartotum does the issue still exist in your work?