I am still lost... I tried this:
UPDATE `grid` SET poly = PolygonFromText(CONCAT('POLYGON(',n,' ',e,', ',s,'
',e,', ',s,' ',w,', ',n,' ',w,', ',n,' ',e,')'));
I had my delimiters mixed up and I know my CONCAT worked:
mysql> select CONCAT('POLYGON(',n,' ',e,', ',s,' ',e,', ',s,' ',w,', ',n,'
',w,', ',n,' ',e,')') from grid limit 3;
+-------------------------------------------------------------------------------------------------------------------------------------------+
| CONCAT('POLYGON(',n,' ',e,', ',s,' ',e,', ',s,' ',w,', ',n,' ',w,', ',n,'
',e,')') |
+-------------------------------------------------------------------------------------------------------------------------------------------+
| POLYGON(49.07756615 101.36211395, 49.07390213 101.36211395, 49.07390213
101.36764145, 49.07756615 101.36764145, 49.07756615 101.36211395) |
| POLYGON(49.08123016 101.36211395, 49.07756615 101.36211395, 49.07756615
101.36764145, 49.08123016 101.36764145, 49.08123016 101.36211395) |
| POLYGON(49.08489418 101.36211395, 49.08123016 101.36211395, 49.08123016
101.36764145, 49.08489418 101.36764145, 49.08489418 101.36211395) |
+-------------------------------------------------------------------------------------------------------------------------------------------+
But after my UPDATE my poly column is still full of NULL values.
Dan
On Sun, 2 May 2010 13:34:14 -0400, Baron Schwartz <ba...@xaprb.com> wrote:
> Dan,
>
> I think you are trying to create a polygon based on the values in
> other columns in the same row. I think these other columns are named
> `n` and so on.
>
> Your mistake is that you are creating a text string, "POLYGON(......)"
> and embedding column names inside it. That won't work. Those column
> names are just part of a string. They are not literal values that the
> POLYGON() function can interpret. You will need to use CONCAT() or
> similar to build a string that POLYGON() can interpret.
>
> On Sun, May 2, 2010 at 11:15 AM, dan <d...@tappin.ca> wrote:
>>
>> I have seen that but I am stuck at just populating my POLYGON column
>> (poly). I have tried this:
>>
>> UPDATE `grid` SET poly = PolygonFromText('POLYGON(`n` `e`, `s` `e`, `s`
>> `w`, `n` `w`, `n` `e`)');
>>
>> but my poly column just reports back NULL.
>>
>> the n, e, s & w columns are decimal lat / long data.
>>
>> Dan
>>
>> On Sun, 2 May 2010 06:43:13 -0700, Ted Yu <yuzhih...@gmail.com> wrote:
>>> I think you may have seen this:
>>> http://dev.mysql.com/doc/refman/5.0/en/relations-on-geometry-mbr.html
>>>
>>> On Sat, May 1, 2010 at 11:12 PM, dan <d...@tappin.ca> wrote:
>>>
>>>>
>>>> Can any one help me with understanding the mysql spatial functions?
I
>>>> can
>>>> only seem to find bits and pieces of how-to's etc.
>>>>
>>>> I have an existing table of lat / long data representing unique
>>>> boundaries
>>>> i.e. rectangles and I want to search the table to find the rectangle
>> that
>>>> bounds a specific point.
>>>>
>>>> Dan
>>>>
>>>> --
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>>>> To unsubscribe:
>> http://lists.mysql.com/mysql?unsub=yuzhih...@gmail.com
>>>>
>>>>
>>
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>>
>
>
>
> --
> Baron Schwartz
> Percona Inc <http://www.percona.com/>
> Consulting, Training, Support & Services for MySQL
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