Re: Issue with em dash character

[Peter Brawley]

On 2015-06-03 2:55 PM, Robert Voliva wrote:

We're finding that, when working with the em dash character, the LEFT and
LENGTH functions don't work well together.  This query shows trying to
strip off the last character from a string containing an em dash:

mysql> select LEFT('031492349−0002,', LENGTH('031492349−0002,') - 1),
LENGTH('031492349−0002,'), LENGTH('031492349-0002,');
++-+---+
| LEFT('031492349−0002,', LENGTH('031492349−0002,') - 1) |
LENGTH('031492349−0002,')   | LENGTH('031492349-0002,') |
++-+---+
| 031492349−0002,|
  17 |15 |
++-+---+
1 row in set (0.06 sec)

Is this a bug?  If it's a "feature", what could we do instead to get around
this issue?


The last of the four '031...' strings in your query diverges from the 
others at the en-dash. In the earlier strings, the dash is a multibyte 
character whose hex value is E2, whereas the dash in the later string is 
the ASCII dash value 2D.


Since the earlier dashes are 3-byte chars, octet_length() returns 17 
instead of 15.


PB

-


Thanks,
Robert Voliva




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Re: Issue with em dash character

[Rik Wasmus]

LENGTH() measures bytes, CHAR_LENGTH() measures characters. There's
little use for LENGTH() for anything else then raw bytes.

On Wed, Jun 3, 2015 at 10:29 PM, Robert Voliva  wrote:
> information_schema.columns reports a character_set_name of 'utf8' and a
> collation_name of 'utf8_general_ci'
>
> On Wed, Jun 3, 2015 at 3:14 PM, Emil Oppeln-Bronikowski 
> wrote:
>
>>
>>  Is this a bug?  If it's a "feature", what could we do instead to get
>>> around
>>> this issue?
>>>
>>
>> Is your column set to unicode?

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Re: Issue with em dash character

[Robert Voliva]

information_schema.columns reports a character_set_name of 'utf8' and a
collation_name of 'utf8_general_ci'

On Wed, Jun 3, 2015 at 3:14 PM, Emil Oppeln-Bronikowski 
wrote:

>
>  Is this a bug?  If it's a "feature", what could we do instead to get
>> around
>> this issue?
>>
>
> Is your column set to unicode?
>
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> For list archives: http://lists.mysql.com/mysql
> To unsubscribe:http://lists.mysql.com/mysql
>
>

Re: Issue with em dash character

[Emil Oppeln-Bronikowski]

Is this a bug?  If it's a "feature", what could we do instead to get around
this issue?


Is your column set to unicode?

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Issue with em dash character

[Robert Voliva]

We're finding that, when working with the em dash character, the LEFT and
LENGTH functions don't work well together.  This query shows trying to
strip off the last character from a string containing an em dash:

mysql> select LEFT('031492349−0002,', LENGTH('031492349−0002,') - 1),
LENGTH('031492349−0002,'), LENGTH('031492349-0002,');
++-+---+
| LEFT('031492349−0002,', LENGTH('031492349−0002,') - 1) |
LENGTH('031492349−0002,')   | LENGTH('031492349-0002,') |
++-+---+
| 031492349−0002,|
 17 |15 |
++-+---+
1 row in set (0.06 sec)

Is this a bug?  If it's a "feature", what could we do instead to get around
this issue?

Thanks,
Robert Voliva