[Tenoke]

Then the useful part is the extra execute function you have to write (it's not just a substitute like in the comment) and an extra function can confirm the safety of a value going into a f-string just as well.

I get the general case, but even then it seems like an implicit anti-pattern over doing db.execute(f"QUERY WHERE name = {safe(name)}")

[ubercore]

Problem with that example is where do you get `safe`? Passing a template into `db.execute` lets the `db` instance handle safety specifically for the backend it's connected to. Otherwise, you'd need to create a `safe` function with a db connection to properly sanitize a string.

And further, if `safe` just returns a string, you still lose out on the ability for `db.execute` to pass the parameter a different way -- you've lost the information that a variable is being interpolated into the string.

[Tenoke]

db.safe same as the new db.execute with safety checks in it you create for the t-string but yes I can see some benefits (though I'm still not a fan for my own codebases so far) with using the values further or more complex cases than this.

[Mawr]

But you have to remember to call the right safe() function every time:

    db.execute(f"QUERY WHERE name = {name}")

    db.execute(f"QUERY WHERE name = {safe_html(name)}")

Oops, you're screwed and there is nothing that can detect that. No such issue with a t-string, it cannot be misused.

[NewEntryHN]

Some SQL engines support accepting parameters separately so that values get bound to the query once the abstract syntax tree is already built, which is way safer than string escapes shenanigans.

[ljm]

I’d always prefer to use a prepared statement if I can, but sadly that’s also less feasible in the fancy new serverless execution environments where the DB adapter often can’t support them.

For me it just makes it easier to identify as safe, because it might not be obvious at a glance that an interpolated template string is properly sanitised.

[dragonwriter]

> and an extra function can confirm the safety of a value going into a f-string just as well.

Yes, you could require consumers to explicitly sanitize each parameter before it goes into the f-string, or, because it has the structure of what is fixed and what is parameters, it can do all of that for all parameters when it gets a t-string.

The latter is far more reliable, and you can't do it with an f-string because an f-string after creation is just a static string with no information about construction.

[zahlman]

> Then the useful part is the extra execute function you have to write

Well, no, the library author writes it. And the library author also gets to detect whether you pass a Template instance as expected, or (erroneously) a string created by whatever formatting method you choose. Having to use `safe(name)` within the f-string loses type information, and risks a greater variety of errors.