Question Re: Error when using TypeScript with CAP in Technology Q&A

Error when using TypeScript with CAP

johnmurray — Tue, 06 Jun 2023 08:41:01 GMT

Hi,

I've migrated one of my CAP projects to TypeScript and all is going well, however in my code I use quite a lot of SELECT.from(table).where(…) which of course TypeScript doesn’t like. I’m importing the types as per import { SELECT } from "@sap/cds/apis/ql" . Now however, when I run my code with cds-ts watch I receive this error Error: Cannot find module '@sap/cds/apis/ql'. Does anyone know how to resolve this? The file is there, and TypeScript is happy with types, so I’m at a loss as to what the problem is. Other imports from cds/apis work too, such as import { Service } from "@sap/cds/apis/services" so it just seems to be the cql stuff that doesn’t work.

I can swap the import statement to

const cds = require("@sap/cds");
const { SELECT } = cds.ql;

which then allows me to run my service at least, but then I lose all TypeScript code help because SELECT becomes type 'any'.

So summarise:

import { SELECT } from "@sap/cds/apis/ql"; // provides TypeScript code completion on SELECT,
                                           // but cds-ts fails to run

const cds = require("@sap/cds");           // cds-ts runs, but TypeScript code completion is
const { SELECT } = cds.ql;                 // lost.

Thanks!

Re: Error when using TypeScript with CAP

former_member631165 — Tue, 20 Jun 2023 13:26:11 GMT

Hi John,

there is no need to require ql statements from cds, as they are globally defined, so code like this should work in TS without importing anything:

const sel = SELECT.from(Foos).columns("x")
sel.from(Foo)
sel.columns("x")<br>

I will still look into the issue, that the code completion is missing, when using cds.ql.SELECT as type.

Re: Error when using TypeScript with CAP

former_member631165 — Wed, 21 Jun 2023 09:19:21 GMT

Btw this also works for me:

import * as cds from "@sap/cds"; 
const { SELECT } = cds.ql
const sel = SELECT.from("Foo")