CAP ex.4 - Error "Cannot find module 'sqlite3'"

[dasast]

Hello, I am trying to finish ex. 4 of SAP Cloud Application Programming Model (CAP).

But whenever I try to click on "Books" at service web page I get an error.

The error in Business Application Studio is

GET /catalog/Books [2020-11-21T20:08:46.513Z | ERROR | 1557126]: { Error: Cannot find module 'sqlite3' at Function.Module._resolveFilename (internal/modules/cjs/loader.js:636:15) at Function.Module._load (internal/modules/cjs/loader.js:562:25) at Module.require (internal/modules/cjs/loader.js:692:17) at require (internal/modules/cjs/helpers.js:25:18) at _loadSqlite (/extbin/npm/globals/lib/node_modules/@sap/cds-runtime/lib/sqlite/Service.js:9:15) at Promise (/extbin/npm/globals/lib/node_modules/@sap/cds-runtime/lib/sqlite/Service.js:31:20) at new Promise () at _new (/extbin/npm/globals/lib/node_modules/@sap/cds-runtime/lib/sqlite/Service.js:30:10) at SQLiteDatabase.acquire (/extbin/npm/globals/lib/node_modules/@sap/cds-runtime/lib/sqlite/Service.js:156:19) at SQLiteDatabase. (/extbin/npm/globals/lib/node_modules/@sap/cds-runtime/lib/sqlite/Service.js:110:29) code: 'MODULE_NOT_FOUND' }

I have installed sqlite and deployed db. npm install sqlite3 -D cds deploy --to sqlite:bookshop.db

I created db connection and connected to it without problem.

I think I followed instructions of this and previous exercises and I don't know what else to do.

Thank you!

[maxstreifeneder]

Hi @dasast,

could you please upload your project as a repo to GitHub so I can run it myself?

Cheers, Max

[dasast]

Hi,

I have decided to try lessons one more time. I deleted my dev space and created new one. But this time I wasn't successful even with deploying.

npm install sqlite3 -D ok cds deploy --to sqlite:bookshop.db ended with error

I created repo https://github.com/dasast/cap_sqlite_error1 with tar.gz file with downloaded dev space. But is almost an initial one.

Thanks for help.

[maxstreifeneder]

HI @dasast,

the repository is unfortunately completely empty.

Regards, Max

[dasast]

Sorry, I probably forgot to commit it. Now it should be OK. Dasa

[maxstreifeneder]

Hm, that's interesting.

I tried npm install followed by npm start and it works for me - can you please try that once again as well?

[dasast]

Well, yes npm install followed by npm start works, but that is not where the problem is. Until the database is deployed, "Books" link returns error "No database connection". So I need to use database.

npm install followed by cds deploy still doesn't work.

And when I earlier was successful with cds deploy, the "Books" link returned error "MODULE_NOT_FOUND'

[qmacro]

Good morning @maxstreifeneder and @dasast - please permit me to join this discussion.

I am guessing from the screenshots you shared, @dasast , that you're doing this in the SAP Business Application Studio - is this correct? Assuming it is, I just tried it, with your tar and gzipped file in that repo you created, and it worked fine. Here's the output of a session just now:

user: user $ cd projects/ 
user: projects $ curl -L https://github.com/dasast/cap_sqlite_error1/raw/main/workspaces-ws-cl4f7.tar.gz | tar xzf -
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   156  100   156    0     0   5571      0 --:--:-- --:--:-- --:--:--  5571
100 6231k  100 6231k    0     0  3458k      0  0:00:01  0:00:01 --:--:-- 7297k
user: projects $ ls
bookshop
user: projects $ cd bookshop/
user: bookshop $ npm install
npm WARN lifecycle The node binary used for scripts is /extbin/bin/node but npm is using /opt/nodejs/node-v10.22.1-linux-x64/bin/node itself. Use the `--scripts-prepend-node-path` option to include the path for the node binary npm was executed with.

> @sap-cloud-sdk/core@1.32.1 postinstall /home/user/projects/bookshop/node_modules/@sap-cloud-sdk/core
> node usage-analytics.js

added 137 packages from 106 contributors and audited 257 packages in 4.074s

5 packages are looking for funding
  run `npm fund` for details

found 0 vulnerabilities

user: bookshop $ cds deploy --to sqlite:bookshop.db
/> successfully deployed to ./bookshop.db

/> updated ./package.json
user: bookshop $ npm start
npm WARN lifecycle The node binary used for scripts is /extbin/bin/node but npm is using /opt/nodejs/node-v10.22.1-linux-x64/bin/node itself. Use the `--scripts-prepend-node-path` option to include the path for the node binary npm was executed with.

> bookshop@1.0.0 start /home/user/projects/bookshop
> npx cds run

[cds] - model loaded from 2 file(s):

  db/schema.cds
  srv/catalog-service.cds

[cds] - connect to db > sqlite { database: 'bookshop.db' }
[cds] - serving CatalogService { at: '/catalog' }

[cds] - launched in: 557.845ms
[cds] - server listening on { url: 'http://localhost:4004' }
[ terminate with ^C ]

and here's the successful retrieval of (no) books:

user: user $ curl http://localhost:4004/catalog/Books
{"@odata.context":"$metadata#Books","value":[]}
user: user $ 

I am therefore wondering whether you have the right tools installed into your Dev Space - did you start with the "SAP Cloud Business Application" type of Dev Space when you create it? Can you please try this flow (above) and let us know what happens?

[dasast]

Hello @qmacro, you are right, I am working in the SAP Business Application Studio as described in Devtoberfest2020 Week 3 SAP Cloud Application Programming Model (CAP).

I am using my trial account, dev space of type SAP Cloud Business Application.

I have tried it and I was successful !

The main reason is that you use command npm install which probably installs more packages than in the video SAP Cloud Application Programming Model - Ex. 03 - Associations & adding persistence used command npm install sqlite3 -D. After npm install I was already successful with command cds deploy --to sqlite:bookshop.db

And also the "Books" link already works.

Thanks very much, I am very happy than I can continue with CAP lessons.

Dasa

[qmacro]

Hey Dasa, thanks, that's great news! Happy hacking!

[vikjdk7]

For me unsetting node path before running CDS deploy worked

run "npm install sqlite3 -D" run "unset NODE_PATH" run "cds deploy --to sqlite"