Struct odbc_api::Prepared

pub struct Prepared<'open_connection> { /* fields omitted */ }

A prepared query. Prepared queries are useful if the similar queries should executed more than once.

Implementations

impl<'o> Prepared<'o>

pub fn execute(
    &mut self,
    params: impl ParameterCollection
) -> Result<Option<CursorImpl<&mut StatementImpl<'o>>>, Error>

Execute the prepared statement.

• params: Used to bind these parameters before executing the statement. You can use () to represent no parameters. In regards to binding arrays of parameters: Should params specify a parameter set size of 0, nothing is executed, and Ok(None) is returned. See the crate::parameter module level documentation for more information on how to pass parameters.

pub fn describe_param(
    &self,
    parameter_number: u16
) -> Result<ParameterDescription, Error>

Describes parameter marker associated with a prepared SQL statement.

Parameters

• parameter_number: Parameter marker number ordered sequentially in increasing parameter order, starting at 1.

Trait Implementations

impl<'o> ResultSetMetadata for Prepared<'o>

type Statement = StatementImpl<'o>

Statement type of the cursor. This is always an instantiation of crate::handles::Statement with a generic parameter indicating the lifetime of the associated connection.

fn stmt_ref(&self) -> &Self::Statement

Get a shared reference to the underlying statement handle. This method is used to implement other more high level methods like Self::describe_col on top of it. It is usually not intended to be called by users of this library directly, but may serve as an escape hatch for low level usecases.

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

Fetch a column description using the column index.

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

Number of columns in result set. Can also be used to see wether execting a prepared Statement (crate::Prepared) would yield a result set, as this would return 0 if it does not.

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

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

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

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

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

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

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

Precision of the column.

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

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>

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.

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

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

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

Data type of the specified column.