==================
Teradata Functions
==================

These functions provide compatibility with Teradata SQL.

String Functions
----------------

.. function:: char2hexint(string) -> varchar

    Returns the hexadecimal representation of the UTF-16BE encoding of the string.

.. function:: index(string, substring) -> bigint

    Alias for :func:`!strpos` function.

.. function:: substring(string, start) -> varchar

    Alias for :func:`!substr` function.

.. function:: substring(string, start, length) -> varchar

    Alias for :func:`!substr` function.

Date Functions
--------------

The functions in this section use a format string that is compatible with
the Teradata datetime functions. The following table, based on the
Teradata reference manual, describes the supported format specifiers:

=============== ===========
Specifier       Description
=============== ===========
``- / , . ; :`` Punctuation characters are ignored
``dd``          Day of month (1-31)
``hh``          Hour of day (1-12)
``hh24``        Hour of the day (0-23)
``mi``          Minute (0-59)
``mm``          Month (01-12)
``ss``          Second (0-59)
``yyyy``        4-digit year
``yy``          2-digit year
=============== ===========

.. warning:: Case insensitivity is not currently supported. All specifiers must be lowercase.

.. function:: to_char(timestamp, format) -> varchar

    Formats ``timestamp`` as a string using ``format``.

.. function:: to_timestamp(string, format) -> timestamp

    Parses ``string`` into a ``TIMESTAMP`` using ``format``.

.. function:: to_date(string, format) -> date

    Parses ``string`` into a ``DATE`` using ``format``.
