Cannot return SQL fragment directly from async function

[langpavel]

I have async helper function which should create SQL fragment. But when I return it directly, it is treated as executable query and this of course fail badly.

Is there possibility to create only SQL fragment, which have not PromiseLike interface?

Example:

This will not work:

  async getSqlFilter(/* ... */): Promise<PendingQuery> {
     return sql`true`;
  }

Workaround – working, but ugly:

  async getSqlFilter(/* ... */): Promise<{ filter: PendingQuery }> {
     return { filter: sql`true` };
  }

Request; proposed API:

  async getSqlFilter(/* ... */): Promise<QueryFragment> {
     return sql.fragment`true`; // this cannot be executed
  }

---

Use case:

  async getSqlFilter(...values: string[]): Promise<QueryFragment> {
     if (values.length === 0) {
       return sql.fragment`true`; // or false, it depends :-)
     } else if (values.length === 1) {
       return sql.fragment`attribute = ${values[0]}`;
     } else {
       return sql.fragment`attribute = ANY(${values})`;
     }
  }

Is there interrest in this feature?

IMHO it's more secure to have fragment and final query separated.

[porsager]

It's only executed if you await it, so just don't make your getSqlFilter function asynchronous.

[langpavel]

But I need my filter function to be asynchronous because it may conditionally do async stuff.