PDAL: readers.pgpointcloud: Unable to fetch pcid with column 'pa' and table 'patches'

[jfjffilk]

when i am trying to run pipeline json file to read from the PostgreSQL database, i get this from readers.pgpointcloud Unable to fetch pcid with column 'pa' and table 'pcpatches'.
if anyone could help me out that would be great. thank you
ps: I am a student and very new pgpointcloud and PDAL

[elemoine]

Could you please provide a test case for this, with an actual pipeline json file and a Pointcloud table example? Please also indicate the versions of PDAL and Pointcloud that you use. Thanks.

[jfjffilk]

I used the following json file to write the data into the database
{
"pipeline": [{
"type": "readers.las",
"filename": "merge.las"
},
{
"type": "filters.chipper",
"capacity": 400
},
{
"type": "writers.pgpointcloud",
"connection": "host='localhost' dbname='postgres' user='postgres',
"table": "patches"
}
]
}

and to read from the database the following file
{
"pipeline":[
{
"type":"readers.pgpointcloud",
"connection":"host='localhost' dbname='postgres' user='postgres',
"table":"patches",
"column":"pa",
},
{
"type":"writers.text",
"filename":"new.txt"
}
]
}

PDAL and pointcloud versions are the latest releases

[trey-stafford]

I am also experiencing this issue. The PDAL's code appears to try to select the pcid value for a patch table in a way similar to how the pointcloud_columns view defines the pcid column (https://github.com/PDAL/PDAL/blob/master/plugins/pgpointcloud/io/PgReader.cpp#L137-L181).

Unfortunately, the pointcloud_columns view also shows no entry for pcid:

valkyrie=# select * from pointcloud_columns;

 schema | table  | column | pcid | srid |  type   
--------+--------+--------+------+------+---------
 public | atm1b  | pa     |      |      | pcpatch
 public | ilvis2 | pa     |      |      | pcpatch

I am using postgresql 9.6.8; pgpointcloud v1.1.0

[trey-stafford]

I have found a solution to this problem: alter the patch colum's data type to include the correct pcid.

For example:

ALTER TABLE atm1b ALTER COLUMN pa SET DATA TYPE PCPATCH({pcid});