Crate odbc_api

About

odbc-api enables you to write applications which utilize ODBC (Open Database Connectivity) standard to access databases. See the guide for more information and code examples.

Re-exports

pub use self::handles::ColumnDescription;

pub use self::handles::DataType;

pub use self::handles::Nullability;

pub use self::parameter::InOut;

pub use self::parameter::Out;

pub use self::parameter::OutputParameter;

pub use odbc_sys as sys;

Modules

buffers

Using buffers to fetch results

guide

Introduction to odbc-api (documentation only)

handles

Provides basic abstraction over valid (i.e. allocated ODBC handles).

parameter

Passing parameters to statement

Structs

Bit

New type wrapping u8 and binding as SQL_BIT.

BlockCursor

In order to save on network overhead, it is recommended to use block cursors instead of fetching values individually. This can greatly reduce the time applications need to fetch data. You can create a block cursor by binding preallocated memory to a cursor using Cursor::bind_buffer. A block cursor saves on a lot of IO overhead by fetching an entire set of rows (called rowset) at once into the buffer bound to it. Reusing the same buffer for each rowset also saves on allocations. A challange with using block cursors might be database schemas with columns there individual fields can be very large. In these cases developers can choose to:

BlockCursorPolling

Asynchronously iterates in blocks (called row sets) over a result set, filling a buffers with a lot of rows at once, instead of iterating the result set row by row. This is usually much faster. Asynchronous sibiling of self::BlockCursor.

ColumnarBulkInserter

Can be used to execute a statement with bulk array paramters. Contrary to its name any statement with parameters can be executed, not only INSERT however inserting large amounts of data in batches is the primary intended use case.

ConcurrentBlockCursor

A wrapper around block cursors which fetches data in a dedicated system thread. Intended to fetch data batch by batch while the application processes the batch last fetched. Works best with a double buffer strategy using two fetch buffers.

Connection

The connection handle references storage of all information about the connection to the data source, including status, transaction state, and error information.

ConnectionOptions

Options to be passed then opening a connection to a datasource.

CursorImpl

Cursors are used to process and iterate the result sets returned by executing queries. Created by either a prepared query or direct execution. Usually utilized through the crate::Cursor trait.

CursorPolling

The asynchronous sibiling of CursorImpl. Use this to fetch results in asynchronous code.

CursorRow

An individual row of an result set. See crate::Cursor::next_row.

DataSourceInfo

Holds name and description of a datasource

DriverInfo

Struct holding information available on a driver. Can be obtained via Environment::drivers.

Environment

An ODBC 3.8 environment.

Narrow

Newtype wrapper intend to be used around Strings or str slices to bind them always as narrow text independent of wether the narrow feature is set or not.

Nullable

Wraps a type T together with an additional indicator. This way the type gains a Null representation, those memory layout is compatible with ODBC.

Preallocated

A preallocated SQL statement handle intended for sequential execution of different queries. See crate::Connection::preallocate.

PreallocatedPolling

Asynchronous sibling of Preallocated using polling mode for execution. Can be obtained using Preallocated::into_polling.

Prepared

A prepared query. Prepared queries are useful if the similar queries should executed more than once. See crate::Connection::prepare.

StatementConnection

Statement handle which also takes ownership of Connection

TooLargeBufferSize

Error indicating a failed allocation for a column buffer

TruncationInfo

Returned by RowSetBuffer::find_truncation. Contains information about the truncation found.

U16Str

16-bit wide string slice with undefined encoding.

U16String

An owned, mutable 16-bit wide string with undefined encoding.

Enums

DriverCompleteOption

Specifies how the driver and driver manager complete the incoming connection string. See crate::Environment::driver_connect.

Error

Error type used to indicate a low level ODBC call returned with SQL_ERROR.

Traits

BoundInputSlice

You can obtain a mutable slice of a column buffer which allows you to change its contents.

Cursor

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

IntoParameter

An instance can be consumed and to create a parameter which can be bound to a statement during execution.

ParameterCollection

Implementers of this trait can be bound to a statement through a self::ParameterCollectionRef.

ParameterCollectionRef

SQL Parameters used to execute a query.

ParameterTupleElement

Implementers of this trait can be used as individual parameters of in a tuple of parameter references. This includes input parameters, output or in/out parameters.

ResultSetMetadata

Provides Metadata of the resulting the result set. Implemented by Cursor types and prepared queries. Fetching metadata from a prepared query might be expensive (driver dependent), so your application should fetch the Metadata it requires from the Cursor if possible.

RowSetBuffer

A Row set buffer binds row, or column wise buffers to a cursor in order to fill them with row sets with each call to fetch.

Sleep

Governs the behaviour of of polling in async functions.

Functions

decimal_text_to_i128

Convert the text representation of a decimal into an integer representation. The integer representation is not truncating the fraction, but is instead the value of the decimal times 10 to the power of scale. E.g. 123.45 of a Decimal with scale 3 is thought of as 123.450 and represented as 123450. This method will regard any non digit character as a radix character with the exception of a + or - at the beginning of the string.

environment

An ODBC Environment with static lifetime. This function always returns a reference to the same instance. The environment is constructed then the function is called for the first time. Every time after the initial construction this function must succeed.

escape_attribute_value

You can use this method to escape a password so it is suitable to be appended to an ODBC connection string as the value for the PWD attribute. This method is only of interest for application in need to create their own connection strings.