Struct Cursor 

pub struct Cursor { /* private fields */ }

An iterator for result sets from MimerSQL databases.

Implementations

impl Cursor

pub fn set_scroll_option(&mut self, option: ScrollOption)

Sets the scroll option for the cursor. Only avaiable for cursors on statements prepared as (scrollable)CursorMode::Scrollable. Valid options are ScrollOption::NEXT, ScrollOption::PREVIOUS, ScrollOption::FIRST, ScrollOption::LAST, ScrollOption::ABSOLUTE, ScrollOption::RELATIVE.

The options are configured as follows

• ScrollOption::NEXT - Moves the cursor to the next row in the result set.
• ScrollOption::PREVIOUS - Moves the cursor to the previous row in the result set.
• ScrollOption::FIRST - Moves the cursor to the first row in the result set.
• ScrollOption::LAST - Moves the cursor to the last row in the result set.
• ScrollOption::ABSOLUTE - Moves the cursor to the specified row in the result set. The row number is specified as a parameter to the scroll method.
• ScrollOption::RELATIVE - Moves the cursor to the specified row relative to the current row. The row number is specified as a parameter to the scroll method.

pub fn scroll(&mut self, idx: i32) -> Result<Option<&Row>, i32>

Moves cursor to specified row index. Takes into consideration the ScrollOption set for the cursor. The default scroll option is ScrollOption::NEXT. To change the scroll option use set_scroll_option.

Errors

Returns Err when the cursor could not be moved to the specified row, e.g. if the specified index is out of bounds.

Examples

let mut conn = Connection::open(db, ident, pass).unwrap();
let stmnt = conn.prepare("SELECT * FROM test_table", CursorMode::Scrollable).unwrap();

let mut cursor = stmnt.open_cursor().unwrap();
let row = cursor.scroll(2).unwrap().expect("Nothing was found on the specified index");

pub fn next_row(&mut self) -> Result<Option<&Row>, i32>

Moves cursor to the next row in the result set and returns its contents. On success, returns either Some(Row) or None if there is no more data to fetch.

Errors

Returns Err when cursor couldn’t advance.

Examples

let mut conn = Connection::open(db, ident, pass).unwrap();
let stmnt = conn.prepare("SELECT * FROM test_table", CursorMode::Forward).unwrap();

let mut cursor = stmnt.open_cursor().unwrap();
let row = cursor.next_row().unwrap().expect("Nothing was found on this row");

pub fn get_mode(&self) -> CursorMode

Returns the CursorMode of the Cursor.

pub fn check_is_mode(&self, mode: CursorMode) -> bool

Checks if the cursor’s mode matches a given CursorMode.

pub fn current_row(&self) -> Result<i32, i32>

Returns current index

pub fn get_row_size(&self) -> Result<i32, i32>

Returns the maximum number of bytes required to hold one row of data. This method might be used to calculate the maximum number of rows allowed in an array fetching scenario under certain memory restrictions.

Trait Implementations

impl Drop for Cursor

fn drop(&mut self)

Executes the destructor for this type.

impl FallibleStreamingIterator for Cursor

type Error = i32

The error type of iteration.

type Item = Row

The type being iterated over.

fn advance(&mut self) -> Result<(), Self::Error>

Advances the iterator to the next position.

fn get(&self) -> Option<&Self::Item>

Returns the current element.

fn next(&mut self) -> Result<Option<&Self::Item>, Self::Error>

Advances the iterator, returning the next element.

fn size_hint(&self) -> (usize, Option<usize>)

Returns bounds on the number of remaining elements in the iterator.

fn all<F>(&mut self, f: F) -> Result<bool, Self::Error>

where Self: Sized, F: FnMut(&Self::Item) -> bool,

Determines if all elements of the iterator satisfy a predicate.

fn any<F>(&mut self, f: F) -> Result<bool, Self::Error>

where Self: Sized, F: FnMut(&Self::Item) -> bool,

Determines if any elements of the iterator satisfy a predicate.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Borrows an iterator, rather than consuming it.

fn count(self) -> Result<usize, Self::Error>

where Self: Sized,

Returns the number of remaining elements in the iterator.

fn filter<F>(self, f: F) -> Filter<Self, F>

where Self: Sized, F: FnMut(&Self::Item) -> bool,

Returns an iterator which filters elements by a predicate.

fn find<F>(&mut self, f: F) -> Result<Option<&Self::Item>, Self::Error>

where Self: Sized, F: FnMut(&Self::Item) -> bool,

Returns the first element of the iterator which satisfies a predicate.

fn for_each<F>(self, f: F) -> Result<(), Self::Error>

where Self: Sized, F: FnMut(&Self::Item),

Calls a closure on each element of an iterator.

fn fuse(self) -> Fuse<Self>

where Self: Sized,

Returns an iterator which is well-behaved at the beginning and end of iteration.

fn map<F, B>(self, f: F) -> Map<Self, F, B>

where Self: Sized, F: FnMut(&Self::Item) -> B,

Returns an iterator which applies a transform to elements.

fn map_ref<F, B>(self, f: F) -> MapRef<Self, F>

where Self: Sized, F: Fn(&Self::Item) -> &B, B: ?Sized,

Returns an iterator which applies a transform to elements.

fn map_err<F, B>(self, f: F) -> MapErr<Self, F>

where Self: Sized, F: Fn(Self::Error) -> B,

Returns an iterator that applies a transform to errors.

fn nth(&mut self, n: usize) -> Result<Option<&Self::Item>, Self::Error>

Returns the nth element of the iterator.

fn position<F>(&mut self, f: F) -> Result<Option<usize>, Self::Error>

where Self: Sized, F: FnMut(&Self::Item) -> bool,

Returns the position of the first element matching a predicate.

fn skip(self, n: usize) -> Skip<Self>

where Self: Sized,

Returns an iterator which skips the first n elements.

fn skip_while<F>(self, f: F) -> SkipWhile<Self, F>

where Self: Sized, F: FnMut(&Self::Item) -> bool,

Returns an iterator which skips the first sequence of elements matching a predicate.

fn take(self, n: usize) -> Take<Self>

where Self: Sized,

Returns an iterator which only returns the first n elements.

fn take_while<F>(self, f: F) -> TakeWhile<Self, F>

where Self: Sized, F: FnMut(&Self::Item) -> bool,

Returns an iterator which only returns the first sequence of elements matching a predicate.