~drizzle-trunk/drizzle/development

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
Length and Size Functions
=========================

.. _char-length-function:

CHAR_LENGTH
-----------
The CHAR_LENGTH(str) function returns string length measured in characters. 

A multi-byte character counts as single character such as a string contains 5 two-byte characters, then LENGTH() function returns 10, but the CHAR_LENGTH() returns 5. ::

	CHARACTER_LENGTH(str)

This function is same as CHAR_LENGTH().

.. _character-length-function:

CHARACTER_LENGTH
----------------

Synonym for CHAR_LENGTH.

.. _length-function:

LENGTH
------

The LENGTH function returns the length of the string argument in bytes. A multi-byte character counts as multiple bytes. This means that for a string containing a three-byte character, LENGTH() returns 3, whereas CHAR_LENGTH() returns 1. For example:

.. code-block:: mysql

	select length('€');

Returns 3

The is because the Euro sign is encoded as 0xE282AC in UTF-8 and thereby occupies 3 bytes.

.. _octet-length-function:

OCTET_LENGTH
-------------

A synonym for LENGTH().