Hi!
Trying to map a data source column via Impala within a virtual graph, I fail to see how I can replace this perfectly working query part into Stardog SMS2:
SUBSTR(location_id, INSTR(location_id, line_number)+4, 4) AS station_number
SUBSTR -> SUBSTRING (that one I figured)
INSTR -> ?
1 Like
STRLEN(STRBEFORE(location_id, line_number))+1 is equivalent to INSTR
If the error you're getting looks something like:
No match found for function signature instr(<CHARACTER>, <CHARACTER>)
... then the error is happening because Stardog's SQL parser doesn't know about the INSTR
function. You can work around this by adding the following to your virtual graph options:
sql.functions=instr:varchar
-Paul
My apologies. I just noticed I made an error. The element after the colon is the return type, so the option should be:
sql.functions=instr:integer
Having the wrong return type can appear to work for simple queries, which is why my test passed.
-Paul