feat: Add Sqllite json_valid #4465
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| /// # } | ||
| /// ``` | ||
| #[sql_name = "json_valid"] | ||
| fn json_valid<J: JsonOrNullableJsonOrJsonbOrNullableJsonb + MaybeNullableValue<Text>>(j: J) -> Integer; |
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| fn json_valid<J: JsonOrNullableJsonOrJsonbOrNullableJsonb + MaybeNullableValue<Text>>(j: J) -> Integer; | |
| fn json_valid<J: JsonOrNullableJsonOrJsonbOrNullableJsonb + MaybeNullableValue<Bool>>(j: J) -> J::Out; |
Diesel maps such flag integers to a boolean for sqlite so we use Bool as return type. That would usually be -> Bool. For this particular function sqlite returns NULL if a null value is passed in, which means we want to return Nullable<Bool> if the input value is nullable and Bool otherwise. The MaybeNullableValue<Bool> part takes care of that by transforming the generic parameter into the right variant. That variant then can be accessed via the Out associated type.
| /// } | ||
| /// | ||
| /// let result = diesel::select(json_valid::<Json>(json!({"x":35}))) | ||
| /// .get_result::<Integer>(connection)?; |
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| /// .get_result::<Integer>(connection)?; | |
| /// .get_result::<bool>(connection)?; |
| /// # | ||
| /// # #[cfg(feature = "serde_json")] | ||
| /// # fn run_test() -> QueryResult<()> { | ||
| /// # use diesel::dsl::{sql, json_pretty_with_indentation}; |
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| /// # use diesel::dsl::{sql, json_pretty_with_indentation}; | |
| /// # use diesel::dsl::{sql, json_valid}; |
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| #[cfg(feature = "sqlite")] | ||
| define_sql_function! { | ||
| /// Returns 1 if the argument is well-formed JSON, or returns 0 if is not well-formed. |
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| /// Returns 1 if the argument is well-formed JSON, or returns 0 if is not well-formed. | |
| /// Returns `true` if the argument is well-formed JSON, or returns `false` if is not well-formed. |
| /// Return type of [`json_valid(json)`](super::functions::json_valid()) | ||
| #[allow(non_camel_case_types)] | ||
| #[cfg(feature = "sqlite")] | ||
| pub type json_valid<E> = super::functions::json_valid<SqlTypeOf<E>, Integer>; |
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| pub type json_valid<E> = super::functions::json_valid<SqlTypeOf<E>, Integer>; | |
| pub type json_valid<E> = super::functions::json_valid<SqlTypeOf<E>, E>; |
That needs to be just E and not Integer as the helper type accepts one generic argument for the SQL type (the SqlTypeOf<E> part) and one generic argument for the expression itself (the E))
(That also means removing the use crate::sql_types::Integer; line again)
Related to #4366
also I couldn't test the functionality fully, and I've asked a question related to testing in #4463