pub trait Statement<'q>: Send + Sync {
type Database: Database;
// Required methods
fn to_owned(&self) -> <Self::Database as HasStatement<'static>>::Statement;
fn sql(&self) -> &str;
fn parameters(
&self
) -> Option<Either<&[<Self::Database as Database>::TypeInfo], usize>>;
fn columns(&self) -> &[<Self::Database as Database>::Column];
fn query(
&self
) -> Query<'_, Self::Database, <Self::Database as HasArguments<'_>>::Arguments>;
fn query_with<'s, A>(&'s self, arguments: A) -> Query<'s, Self::Database, A>
where A: IntoArguments<'s, Self::Database>;
fn query_as<O>(
&self
) -> QueryAs<'_, Self::Database, O, <Self::Database as HasArguments<'_>>::Arguments>
where O: for<'r> FromRow<'r, <Self::Database as Database>::Row>;
fn query_as_with<'s, O, A>(
&'s self,
arguments: A
) -> QueryAs<'s, Self::Database, O, A>
where O: for<'r> FromRow<'r, <Self::Database as Database>::Row>,
A: IntoArguments<'s, Self::Database>;
fn query_scalar<O>(
&self
) -> QueryScalar<'_, Self::Database, O, <Self::Database as HasArguments<'_>>::Arguments>
where (O,): for<'r> FromRow<'r, <Self::Database as Database>::Row>;
fn query_scalar_with<'s, O, A>(
&'s self,
arguments: A
) -> QueryScalar<'s, Self::Database, O, A>
where (O,): for<'r> FromRow<'r, <Self::Database as Database>::Row>,
A: IntoArguments<'s, Self::Database>;
// Provided methods
fn column<I>(&self, index: I) -> &<Self::Database as Database>::Column
where I: ColumnIndex<Self> { ... }
fn try_column<I>(
&self,
index: I
) -> Result<&<Self::Database as Database>::Column, Error>
where I: ColumnIndex<Self> { ... }
}
Expand description
An explicitly prepared statement.
Statements are prepared and cached by default, per connection. This type allows you to look at that cache in-between the statement being prepared and it being executed. This contains the expected columns to be returned and the expected parameter types (if available).
Statements can be re-used with any connection and on first-use it will be re-prepared and cached within the connection.
Required Associated Types§
Required Methods§
sourcefn to_owned(&self) -> <Self::Database as HasStatement<'static>>::Statement
fn to_owned(&self) -> <Self::Database as HasStatement<'static>>::Statement
Creates an owned statement from this statement reference. This copies the original SQL text.
sourcefn parameters(
&self
) -> Option<Either<&[<Self::Database as Database>::TypeInfo], usize>>
fn parameters( &self ) -> Option<Either<&[<Self::Database as Database>::TypeInfo], usize>>
Get the expected parameters for this statement.
The information returned depends on what is available from the driver. SQLite can only tell us the number of parameters. PostgreSQL can give us full type information.
sourcefn columns(&self) -> &[<Self::Database as Database>::Column]
fn columns(&self) -> &[<Self::Database as Database>::Column]
Get the columns expected to be returned by executing this statement.
fn query( &self ) -> Query<'_, Self::Database, <Self::Database as HasArguments<'_>>::Arguments>
fn query_with<'s, A>(&'s self, arguments: A) -> Query<'s, Self::Database, A>where
A: IntoArguments<'s, Self::Database>,
fn query_as<O>( &self ) -> QueryAs<'_, Self::Database, O, <Self::Database as HasArguments<'_>>::Arguments>
fn query_as_with<'s, O, A>( &'s self, arguments: A ) -> QueryAs<'s, Self::Database, O, A>
fn query_scalar<O>( &self ) -> QueryScalar<'_, Self::Database, O, <Self::Database as HasArguments<'_>>::Arguments>
fn query_scalar_with<'s, O, A>( &'s self, arguments: A ) -> QueryScalar<'s, Self::Database, O, A>
Provided Methods§
sourcefn column<I>(&self, index: I) -> &<Self::Database as Database>::Columnwhere
I: ColumnIndex<Self>,
fn column<I>(&self, index: I) -> &<Self::Database as Database>::Columnwhere
I: ColumnIndex<Self>,
Gets the column information at index
.
A string index can be used to access a column by name and a usize
index
can be used to access a column by position.
Panics
Panics if index
is out of bounds.
See try_column
for a non-panicking version.
sourcefn try_column<I>(
&self,
index: I
) -> Result<&<Self::Database as Database>::Column, Error>where
I: ColumnIndex<Self>,
fn try_column<I>(
&self,
index: I
) -> Result<&<Self::Database as Database>::Column, Error>where
I: ColumnIndex<Self>,
Gets the column information at index
or None
if out of bounds.