Struct Descriptor

pub struct Descriptor<'stmt> { /* private fields */ }

A descriptor associated with a statement. This wrapper does not wrap explicitly allocated descriptors which have the connection as parent, but usually implicitly allocated ones associated with the statement. It could also represent an explicitly allocated one, but ony in the context there it is associated with a statement and currently borrowed from it.

• IPD Implementation parameter descriptor
• APD Application parameter descriptor
• IRD Implemenation row descriptor
• ARD Application row descriptor

Implementations

impl<'stmt> Descriptor<'stmt>

pub unsafe fn new(handle: HDesc) -> Self

Safety

Call this method only with a valid (successfully allocated) ODBC descriptor handle.

pub fn as_sys(&self) -> HDesc

Directly acces the underlying ODBC handle.

pub fn set_precision( &mut self, rec_number: i16, precision: i16, ) -> SqlResult<()>

Number of digits for an exact numeric type, the number of bits in the mantissa (binary precision) for an approximate numeric type, or the numbers of digits in the fractional seconds component for the SQL_TYPE_TIME, SQL_TYPE_TIMESTAMP, or SQL_INTERVAL_SECOND data type. This field is undefined for all other data types. See: https://learn.microsoft.com/sql/odbc/reference/syntax/sqlsetdescfield-function

pub fn set_scale(&mut self, rec_number: i16, scale: i16) -> SqlResult<()>

The defined scale for decimal and numeric data types. The field is undefined for all other data types.

pub unsafe fn set_type( &mut self, rec_number: i16, c_type: CDataType, ) -> SqlResult<()>

C-Type bound to the data pointer.

Safety

The buffer bound to the data pointer in ARD must match, otherwise calls to fetch might e.g. write beyond the bounds of these types, if e.g. a larger type is bound

pub unsafe fn set_data_ptr( &mut self, rec_number: i16, data_ptr: Pointer, ) -> SqlResult<()>

Data pointer filled with values from the source when fetching data.

Safety

Pointer must be valid and match the description set using set_type.

Trait Implementations

impl<'stmt> AsHandle for Descriptor<'stmt>

fn as_handle(&self) -> Handle

The raw underlying ODBC handle used to talk to the ODBC C API. The handle must be valid.

fn handle_type(&self) -> HandleType

The type of the ODBC handle returned by as_handle. This is a method rather than a constant in order to make the type object safe.