AS keyword error

[chrisdusovic]

According to the BQL overview document, the "as" keyword should be able to be used to return a different name for variables. However, the keyword causes an error when running the program. The keyword only works when used with an aggregation.

When running this program:

# Create a graph.
CREATE GRAPH ?family;

# Insert some data into the graph.
INSERT DATA INTO ?family {
  /u<joe> "parent_of"@[] /u<mary> .
  /u<joe> "parent_of"@[] /u<peter> .
  /u<peter> "parent_of"@[] /u<john> .
  /u<peter> "parent_of"@[] /u<eve>
};

# Find all Joe's offspring names.
# Works fine without "as" keyword.
SELECT ?name
FROM ?family
WHERE {
  /u<joe> "parent_of"@[] ?offspring ID ?name
};

# Find all Joe's offspring names.
# Fails with "as" keyword.
SELECT ?name as ?n
FROM ?family
WHERE {
  /u<joe> "parent_of"@[] ?offspring ID ?name
};

# Count offspring.
# Works with "as" keyword.
SELECT ?parent_name, count(?name) as ?n
FROM ?family
WHERE {
  ?parent ID ?parent_name "parent_of"@[] ?offspring ID ?name
}
GROUP BY ?parent_name;

# Drop the graph.
DROP GRAPH ?family;

The output is:

Processing file bug.bql

Processing statement (1/6):
CREATE GRAPH ?family;

Result:
OK

Processing statement (2/6):
INSERT DATA INTO ?family { /u<joe> "parent_of"@[] /u<mary> . /u<joe> "parent_of"@[] /u<peter> . /u<peter> "parent_of"@[] /u<john> . /u<peter> "parent_of"@[] /u<eve> };

Result:
OK

Processing statement (3/6):
SELECT ?name FROM ?family WHERE { /u<joe> "parent_of"@[] ?offspring ID ?name };

Result:
?name
mary
peter

OK

Processing statement (4/6):
SELECT ?name as ?n FROM ?family WHERE { /u<joe> "parent_of"@[] ?offspring ID ?name };

[FAIL] [ERROR] Failed to execute BQL statement with error cannot project against unknow binding ?n; known bindinds are [?offspring ?name]

Processing statement (5/6):
SELECT ?parent_name, count(?name) as ?n FROM ?family WHERE { ?parent ID ?parent_name "parent_of"@[] ?offspring ID ?name } GROUP BY ?parent_name;

Result:
?parent_name    ?n
joe "2"^^type:int64
peter   "2"^^type:int64

OK

Processing statement (6/6):
DROP GRAPH ?family;

Result:
OK

[xllora]

Bug was fixed via pull request #49