Struct odbc_api::Nullable

source · [−]

pub struct Nullable<T> { /* private fields */ }

Expand description

Wraps a type T together with an additional indicator. This way the type gains a Null representation, those memory layout is compatible with ODBC.

Implementations

impl<T> Nullable<T>

pub fn new(value: T) -> Self

pub fn null() -> Self where
T: Default,

pub fn as_opt(&self) -> Option<&T>

pub fn into_opt(self) -> Option<T>

Trait Implementations

impl<T> CData for Nullable<T> where
T: Pod,

fn cdata_type(&self) -> CDataType

The identifier of the C data type of the value buffer. When it is retrieving data from the data source with fetch, the driver converts the data to this type. When it sends data to the source, the driver converts the data from this type. Read more

fn indicator_ptr(&self) -> *const isize

Indicates the length of variable sized types. May be zero for fixed sized types. Used to determine the size or existence of input parameters. Read more

fn value_ptr(&self) -> *const c_void

Pointer to a value corresponding to the one described by cdata_type.

fn buffer_length(&self) -> isize

Maximum length of the type in bytes (not characters). It is required to index values in bound buffers, if more than one parameter is bound. Can be set to zero for types not bound as parameter arrays, i.e. CStr. Read more

impl<T> CDataMut for Nullable<T> where
T: Pod,

fn mut_indicator_ptr(&mut self) -> *mut isize

Indicates the length of variable sized types. May be zero for fixed sized types.

fn mut_value_ptr(&mut self) -> *mut c_void

Pointer to a value corresponding to the one described by cdata_type.

impl<T: Clone> Clone for Nullable<T>

fn clone(&self) -> Nullable<T>

Returns a copy of the value. Read more

1.0.0 · source

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more

impl<T> HasDataType for Nullable<T> where
T: Pod + HasDataType,

fn data_type(&self) -> DataType

The SQL data as which the parameter is bound to ODBC.

impl<T: Copy> Copy for Nullable<T>

impl<T> InputParameter for Nullable<T> where
T: Pod + HasDataType,

impl<T> OutputParameter for Nullable<T> where
T: Pod + HasDataType,

Auto Trait Implementations

impl<T> RefUnwindSafe for Nullable<T> where
T: RefUnwindSafe,

impl<T> Send for Nullable<T> where
T: Send,

impl<T> Sync for Nullable<T> where
T: Sync,

impl<T> Unpin for Nullable<T> where
T: Unpin,

impl<T> UnwindSafe for Nullable<T> where
T: UnwindSafe,

Blanket Implementations

impl<T> Any for T where
T: 'static + ?Sized,

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more

impl<T> Borrow<T> for T where
T: ?Sized,

const: unstable · source

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more

impl<T> BorrowMut<T> for T where
T: ?Sized,

const: unstable · source

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more

impl<T> From<T> for T

const: unstable · source

fn from(t: T) -> T

Returns the argument unchanged.

impl<T, U> Into<U> for T where
U: From<T>,

const: unstable · source

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

impl<T> ToOwned for T where
T: Clone,

type Owned = T

The resulting type after obtaining ownership.

fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more

fn clone_into(&self, target: &mut T)

🔬 This is a nightly-only experimental API. (toowned_clone_into)

Uses borrowed data to replace owned data, usually by cloning. Read more

impl<T, U> TryFrom<U> for T where
U: Into<T>,

type Error = Infallible

The type returned in the event of a conversion error.

const: unstable · source

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.

impl<T, U> TryInto<U> for T where
U: TryFrom<T>,

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.

const: unstable · source

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.