Struct rusqlite::functions::Context

pub struct Context<'a> { /* private fields */ }

Available on crate feature functions only.

Context is a wrapper for the SQLite function evaluation context.

Implementations

impl Context<'_>

pub fn len(&self) -> usize

Returns the number of arguments to the function.

pub fn is_empty(&self) -> bool

Returns true when there is no argument.

pub fn get<T: FromSql>(&self, idx: usize) -> Result<T>

Returns the idxth argument as a T.

Failure

Will panic if idx is greater than or equal to self.len().

Will return Err if the underlying SQLite type cannot be converted to a T.

pub fn get_raw(&self, idx: usize) -> ValueRef<'_>

Returns the idxth argument as a ValueRef.

Failure

Will panic if idx is greater than or equal to self.len().

pub fn get_arg(&self, idx: usize) -> SqlFnArg

Returns the idxth argument as a SqlFnArg. To be used when the SQL function result is one of its arguments.

pub fn get_subtype(&self, idx: usize) -> c_uint

Returns the subtype of idxth argument.

Failure

Will panic if idx is greater than or equal to self.len().

pub fn get_or_create_aux<T, E, F>(&self, arg: c_int, func: F) -> Result<Arc<T>>

where T: Send + Sync + 'static, E: Into<Box<dyn Error + Send + Sync + 'static>>, F: FnOnce(ValueRef<'_>) -> Result<T, E>,

Fetch or insert the auxiliary data associated with a particular parameter. This is intended to be an easier-to-use way of fetching it compared to calling get_aux and set_aux separately.

See https://www.sqlite.org/c3ref/get_auxdata.html for a discussion of this feature, or the unit tests of this module for an example.

pub fn set_aux<T: Send + Sync + 'static>( &self, arg: c_int, value: T ) -> Result<Arc<T>>

Sets the auxiliary data associated with a particular parameter. See https://www.sqlite.org/c3ref/get_auxdata.html for a discussion of this feature, or the unit tests of this module for an example.

pub fn get_aux<T: Send + Sync + 'static>( &self, arg: c_int ) -> Result<Option<Arc<T>>>

Gets the auxiliary data that was associated with a given parameter via set_aux. Returns Ok(None) if no data has been associated, and Ok(Some(v)) if it has. Returns an error if the requested type does not match.

pub unsafe fn get_connection(&self) -> Result<ConnectionRef<'_>>

Get the db connection handle via sqlite3_context_db_handle

Safety

This function is marked unsafe because there is a potential for other references to the connection to be sent across threads, see this comment.