diesel/sqlite/mod.rs
1//! Provides types and functions related to working with SQLite
2//!
3//! Much of this module is re-exported from database agnostic locations.
4//! However, if you are writing code specifically to extend Diesel on
5//! SQLite, you may need to work with this module directly.
6
7pub(crate) mod backend;
8mod connection;
9pub mod expression;
10
11pub mod query_builder;
12
13mod types;
14
15pub use self::backend::{Sqlite, SqliteType};
16pub use self::connection::SerializedDatabase;
17pub use self::connection::SqliteBindValue;
18pub use self::connection::SqliteConnection;
19pub use self::connection::SqliteValue;
20pub use self::query_builder::SqliteQueryBuilder;
21
22/// Trait for the implementation of a SQLite aggregate function
23///
24/// This trait is to be used in conjunction with the `define_sql_function!`
25/// macro for defining a custom SQLite aggregate function. See
26/// the documentation [there](super::prelude::define_sql_function!) for details.
27pub trait SqliteAggregateFunction<Args>: Default {
28 /// The result type of the SQLite aggregate function
29 type Output;
30
31 /// The `step()` method is called once for every record of the query.
32 ///
33 /// This is called through a C FFI, as such panics do not propagate to the caller. Panics are
34 /// caught and cause a return with an error value. The implementation must still ensure that
35 /// state remains in a valid state (refer to [`std::panic::UnwindSafe`] for a bit more detail).
36 fn step(&mut self, args: Args);
37
38 /// After the last row has been processed, the `finalize()` method is
39 /// called to compute the result of the aggregate function. If no rows
40 /// were processed `aggregator` will be `None` and `finalize()` can be
41 /// used to specify a default result.
42 ///
43 /// This is called through a C FFI, as such panics do not propagate to the caller. Panics are
44 /// caught and cause a return with an error value.
45 fn finalize(aggregator: Option<Self>) -> Self::Output;
46}
47
48/// SQLite specific sql types
49pub mod sql_types {
50 #[doc(inline)]
51 pub use super::types::Timestamptz;
52}