Struct odbc_api::parameter::VarChar

pub struct VarChar<'a> { /* fields omitted */ }

Binds a byte array as a VarChar input parameter.

While a byte array can provide us with a pointer to the start of the array and the length of the array itself, it can not provide us with a pointer to the length of the buffer. So to bind strings which are not zero terminated we need to store the length in a separate value.

This type is created if into_parameter of the IntoParameter trait is called on a &str.

Example

use odbc_api::{Environment, IntoParameter};

let env = unsafe {
    Environment::new()?
};

let mut conn = env.connect("YourDatabase", "SA", "<YourStrong@Passw0rd>")?;
if let Some(cursor) = conn.execute(
    "SELECT year FROM Birthdays WHERE name=?;",
    "Bernd".into_parameter())?
{
    // Use cursor to process query results.
};

Implementations

impl<'a> VarChar<'a>

pub fn new(value: &'a [u8]) -> Self

Constructs a new VarChar containing the text in the specified buffer.

pub fn null() -> Self

Constructs a new VarChar representing the NULL value.

Trait Implementations

impl<'_> CData for VarChar<'_>

pub 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.

pub fn indicator_ptr(&self) -> *const isize

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

pub fn value_ptr(&self) -> *const c_void

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

pub fn buffer_length(&self) -> isize

Maximum length of the type. 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.

impl<'_> Input for VarChar<'_>

pub fn data_type(&self) -> DataType

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

impl<'_> Parameter for VarChar<'_>