[postgis-users] Aggregate Function Malfunction

[Mark Fenbers]

Yes, it reports the same error with no results.  Other ideas?
Mark

Stephen Woodbridge wrote:

> Mark,
>
> Did you try something like:
>
> SELECT IsValid( MultiIntersection( the_geom )) FROM myTable WHERE 
> IsValid(the_geom);
>
> to see what it reports?
>
> -Steve
>
> Mark Fenbers wrote:
>
>> I have a table populated with geometries (polygons to be exact) that 
>> were created with other PostGIS functions.  They were added to this 
>> table after passing the IsValid() test.  A SELECT query using 
>> IsValid() verifies that all geometries in the table are valid.  But 
>> when I run the query,
>>
>> SELECT Npoints( MultiIntersection( the_geom )) FROM myTable WHERE 
>> IsValid(the_geom);
>>
>> I get an error "parse error - invalid geometry".  I cannot tell which 
>> record is triggering the error because MultiIntersection() is an 
>> *aggregate* function I created to take the cumulative Intersection() 
>> of several polygons in the table (one per row).  It is defined as such:
>>
>> CREATE AGGREGATE MultiIntersection (
>>    BASETYPE = GEOMETRY,
>>    SFUNC = Intersection,
>>    STYPE = GEOMETRY,
>>    INITCOND = ''
>> );
>>
>> I'm going on the assumption that, because this is my first attempt at 
>> my own aggregate function, I am doing something incorrectly.  But I 
>> can figure out what it is I am doing wrong.  Can you help, please?
>> Some of my cluelessness may be in part due to a lack of my 
>> understanding the STYPE, and BASETYPE parameters as well as what the 
>> INITCOND setting should be.  I have not successfully found any 
>> documentation on these other than syntax and examples.
>>
>> Mark
>
>
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