[−][src]Struct odbc_api::handles::Statement

pub struct Statement<'s> { /* fields omitted */ }

Wraps a valid (i.e. successfully allocated) ODBC statement handle.

Implementations

`impl<'s> Statement<'s>`[src]

`pub unsafe fn new(handle: HStmt) -> Self`[src]

Safety

handle must be a valid (successfully allocated) statement handle.

`pub unsafe fn exec_direct( &mut self, statement_text: &U16Str ) -> Result<bool, Error>`[src]

Executes a prepareable statement, using the current values of the parameter marker variables if any parameters exist in the statement. SQLExecDirect is the fastest way to submit an SQL statement for one-time execution.

Safety

While self as always guaranteed to be a valid allocated handle, this function may dereference bound parameters. It is the callers responsibility to ensure these are still valid. One strategy is to reset potentially invalid parameters right before the call using reset_parameters.

Return

Returns true if a cursor is created. If false is returned no cursor has been created ( e.g. the query came back empty). Note that an empty query may also create a cursor with zero rows. If a cursor is created. close_cursor should be called after it is no longer used.

`pub fn prepare(&mut self, statement_text: &U16Str) -> Result<(), Error>`[src]

Send an SQL statement to the data source for preparation. The application can include one or more parameter markers in the SQL statement. To include a parameter marker, the application embeds a question mark (?) into the SQL string at the appropriate position.

`pub fn execute(&mut self) -> Result<(), Error>`[src]

Executes a statement prepared by prepare. After the application processes or discards the results from a call to execute, the application can call SQLExecute again with new parameter values.

Safety

While self as always guaranteed to be a valid allocated handle, this function may dereference bound parameters. It is the callers responsibility to ensure these are still valid. One strategy is to reset potentially invalid parameters right before the call using reset_parameters.

`pub fn close_cursor(&mut self) -> Result<(), Error>`[src]

Close an open cursor.

`pub 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.

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

Number of columns in result set.

`pub unsafe fn set_row_array_size(&mut self, size: u32) -> Result<(), Error>`[src]

Sets the batch size for bulk cursors, if retrieving many rows at once.

Safety

It is the callers responsibility to ensure that buffers bound using bind_col can hold the specified amount of rows.

`pub unsafe fn set_num_rows_fetched( &mut self, num_rows: &mut ULen ) -> Result<(), Error>`[src]

Bind an integer to hold the number of rows retrieved with fetch in the current row set.

Safety

num_rows must not be moved and remain valid, as long as it remains bound to the cursor.

`pub unsafe fn set_row_bind_type(&mut self, row_size: u32) -> Result<(), Error>`[src]

Sets the binding type to columnar binding for batch cursors.

Any Positive number indicates a row wise binding with that row length. 0 indicates a columnar binding.

Safety

It is the callers responsibility to ensure that the bound buffers match the memory layout specified by this function.

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

Returns the next rowset in the result set.

It can be called only while a result set exists: I.e., after a call that creates a result set and before the cursor over that result set is closed. 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.

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

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

`pub unsafe fn bind_col( &mut self, column_number: u16, target_type: CDataType, target_value: Pointer, target_length: Len, indicator: *mut Len ) -> 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.

`pub unsafe fn bind_parameter( &mut self, parameter_number: u16, input_output_type: ParamType, value_type: CDataType, parameter_type: DataType, parameter_value_ptr: Pointer, buffer_length: Len, str_len_or_ind_ptr: *mut Len ) -> Result<(), Error>`[src]

Binds a buffer to a parameter marker in an SQL statement.

See https://docs.microsoft.com/en-us/sql/odbc/reference/syntax/sqlbindparameter-function.

Parameters

...

buffer_length: Used to calculate the position of individual parameters then binding buffers or to truncate binary and character data in case of output. ...

Safety

It is up to the caller to ensure the lifetimes of the bound parameters.
Calling this function may influence other statements that share the APD.