Trait odbc_api::Cursor[−][src]

pub trait Cursor: Sized {
    fn describe_col(
        &self, 
        column_number: u16, 
        column_description: &mut ColumnDescription
    ) -> Result<(), Error>;

    fn num_result_cols(&self) -> Result<i16, Error>;

    unsafe fn fetch(&mut self) -> Result<bool, Error>;

    fn unbind_cols(&mut self) -> Result<(), Error>;

    unsafe fn bind_col(
        &mut self, 
        column_number: u16, 
        target: &mut impl CDataMut
    ) -> Result<(), Error>;

    fn is_unsigned_column(&self, column_number: u16) -> Result<bool, Error>;

    fn bind_buffer<B>(
        self, 
        row_set_buffer: B
    ) -> Result<RowSetCursor<Self, B>, Error>
    where
        B: RowSetBuffer;

    fn col_data_type(&self, column_number: u16) -> Result<DataType, Error>;

    fn col_octet_length(&self, column_number: u16) -> Result<isize, Error>;

    fn col_display_size(&self, column_number: u16) -> Result<isize, Error>;

    fn col_precision(&self, column_number: u16) -> Result<isize, Error>;

    fn col_scale(&self, column_number: u16) -> Result<isize, Error>;

    fn col_name(
        &self, 
        column_number: u16, 
        buf: &mut Vec<u16>
    ) -> Result<(), Error>;

    fn column_names(&self) -> Result<ColumnNamesIt<'_, Self>, Error> { ... }
}

Cursors are used to process and iterate the result sets returned by executing queries.

Required methods

fn describe_col(
    &self,
    column_number: u16,
    column_description: &mut ColumnDescription
) -> Result<(), Error>[src]

Fetch a column description using the column index.

Parameters

  • column_number: Column index. 0 is the bookmark column. The other column indices start with 1.
  • column_description: Holds the description of the column after the call. This method does not provide strong exception safety as the value of this argument is undefined in case of an error.

fn num_result_cols(&self) -> Result<i16, Error>[src]

Number of columns in result set.

unsafe fn fetch(&mut self) -> Result<bool, Error>[src]

Returns the next set of rows in the result set.

If any columns are bound, it returns the data in those columns. If the application has specified a pointer to a row status array or a buffer in which to return the number of rows fetched, fetch also returns this information. Calls to fetch can be mixed with calls to fetch_scroll.

Safety

Fetch dereferences bound buffers and is therefore unsafe.

fn unbind_cols(&mut self) -> Result<(), Error>[src]

Release all column buffers bound by bind_col. Except bookmark column.

unsafe fn bind_col(
    &mut self,
    column_number: u16,
    target: &mut impl CDataMut
) -> Result<(), Error>[src]

Binds application data buffers to columns in the result set

  • column_number: 0 is the bookmark column. It is not included in some result sets. All other columns are numbered starting with 1. It is an error to bind a higher-numbered column than there are columns in the result set. This error cannot be detected until the result set has been created, so it is returned by fetch, not bind_col.
  • target_type: 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.
  • target_value: Pointer to the data buffer to bind to the column.
  • target_length: Length of target value in bytes. (Or for a single element in case of bulk aka. block fetching data).
  • indicator: Buffer is going to hold length or indicator values.

Safety

It is the callers responsibility to make sure the bound columns live until they are no longer bound.

fn is_unsigned_column(&self, column_number: u16) -> Result<bool, Error>[src]

true if a given column in a result set is unsigned or not a numeric type, false otherwise.

column_number: Index of the column, starting at 1.

fn bind_buffer<B>(
    self,
    row_set_buffer: B
) -> Result<RowSetCursor<Self, B>, Error> where
    B: RowSetBuffer, [src]

Binds this cursor to a buffer holding a row set.

fn col_data_type(&self, column_number: u16) -> Result<DataType, Error>[src]

Data type of the specified column.

column_number: Index of the column, starting at 1.

fn col_octet_length(&self, column_number: u16) -> Result<isize, Error>[src]

Returns the size in bytes of the columns. For variable sized types the maximum size is returned, excluding a terminating zero.

column_number: Index of the column, starting at 1.

fn col_display_size(&self, column_number: u16) -> Result<isize, Error>[src]

Maximum number of characters required to display data from the column.

column_number: Index of the column, starting at 1.

fn col_precision(&self, column_number: u16) -> Result<isize, Error>[src]

Precision of the column.

Denotes the applicable precision. For data types SQL_TYPE_TIME, SQL_TYPE_TIMESTAMP, and all the interval data types that represent a time interval, its value is the applicable precision of the fractional seconds component.

fn col_scale(&self, column_number: u16) -> Result<isize, Error>[src]

The applicable scale for a numeric data type. For DECIMAL and NUMERIC data types, this is the defined scale. It is undefined for all other data types.

fn col_name(&self, column_number: u16, buf: &mut Vec<u16>) -> Result<(), Error>[src]

The column alias, if it applies. If the column alias does not apply, the column name is returned. If there is no column name or a column alias, an empty string is returned.

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Provided methods

fn column_names(&self) -> Result<ColumnNamesIt<'_, Self>, Error>[src]

Use this if you want to iterate over all column names and allocate a String for each one.

This is a wrapper around col_name introduced for convenience.

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Implementors

impl<'o, S> Cursor for CursorImpl<'o, S> where
    S: BorrowMut<Statement<'o>>, [src]

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