How to use SQLite in Qt WebAssembly

Kallappa

Hi,

I have Qt WASM Setup on Ubuntu-18.04 (Evaluation version - Prebuilt binaries version Qt5.14.0)

and now the i am trying to use Qt Applications with Sqlite, So in many websites i got only answer is QSQlite is not soupporting Qt WASM.
and i have tried to build with qmake as follows but no use at all.

(navigate to Qt installation folder or sql driver plugin source code and compile using qmake)

cd /home/kmb/Qt/5.14.0/Src/qtbase/src/plugins/sqldrivers

source /home/kmb/Qtwasm/emsdk/emsdk_env.sh
/home/kmb/Qt/5.14.0/wasm_32/bin/qmake ..

then i got error as
Project ERROR: Could not find feature sql-psql

then from Qt Document i found
https://doc.qt.io/qt-5/sql-driver.html#how-to-build-the-qpsql-plugin-on-unix-and-macos

~/Qt/5.14.0/wasm_32/bin/qmake .. -- PSQL_INCDIR=/usr/include/pgsql

then i got error as
Project ERROR: You cannot configure sqldrivers separately within a top-level build.

i am searching for the build steps and the Sqlite plugin source code but still i didn't get succed with it. Please suggest me what i am doing wrong aand if any procedure to achieve this.

Thanks in advance

JonB

@Kallappa
My very lmited understanding is that you are not supposed to/it is not easy to use SQLite with WASM. WASM does not have access to the local file system, there are mentions of ways to "sync" WASM's storage area with the permanent local file system.

There is one bug report raised discussing this at https://bugreports.qt.io/browse/QTBUG-70443. I don't know if that is still current. See also https://forum.qt.io/topic/94418/qt-web-assembly-support-for-sqlite-database-only-memory-db, https://wiki.qt.io/Qt_for_WebAssembly#Known_issues_and_platform_notes, and https://stackoverflow.com/questions/62114820/how-to-use-sqlite-in-qt-webassembly asked/answered just a couple of months ago.

@lorn-potter is the guy to answer this definitively, if he sees this.

sharath

@JonB I know Qtsql module not supported in Wasm. i believe wasm supports virtual file system and tried QFile read and write operation. why Qt still not support for SQL? even i need Sqlite should work on wasm.
@lorn-potter can you please answer for this?

thanks,