Add SQLite function json_pretty
#4395
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Related to Issue #4366 |
| /// # Ok(()) | ||
| /// # } | ||
| /// ``` | ||
| fn json_pretty<E: TextOrNullableTextOrBinaryOrNullableBinary + MaybeNullableValue<Text>>(e: E) -> E::Out; |
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I think this signature is unfortunately not correct yet. The sqlite documentation says:
The json_pretty() function works like json() except that it adds extra whitespace to make the JSON result easier for humans to read. The first argument is the JSON or JSONB that is to be pretty-printed. The optional second argument is a text string that is used for indentation. If the second argument is omitted or is NULL, then indentation is four spaces per level.
which would translate to
fn json_pretty<J: JsonOrJsonbOrNullableJson + MaybeNullableValue<Text>>(j: J) -> J::Out;this then would require users to call it that way: select(json_pretty(json("your_json_text")) or select(json_pretty(jsonb(b"your_json_blob"))
As for the optional second argument: We normally deal with that by having a second function definition for this for that.
So something like:
#[sql_name = "json_pretty"]
fn json_pretty_with_indentation<J: JsonOrJsonbOrNullableJson + MaybeNullableValue<Text>>(j: J, indentation: Nullable<Text>) -> J::Out;There was a problem hiding this comment.
Very helpful for me since I'm new to diesel ! Well, are you sure we should use JsonOrJsonbOrNullableJson ? I found JsonOrNullableJsonOrJsonbOrNullableJsonb in the PostgreSQL implementation, which adds nullable JSONB implementation.
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You are correct we want to use JsonOrNullableJsonOrJsonbOrNullableJsonb there (any likely also for most of the other sqlite json functions).
TextOrNullableTextOrBinaryOrNullableBinary. SQLite doc says "the first argument is the JSON or JSONB that is to be pretty-printed" so I added such a trait. I don't know whether it's proper.