optional match query error A result was returned when none was expected.;

[VinACE]

[FAIL] DataAccessException->StatementCallback; SQL [ OPTIONAL MATCH (m : mat )-[ r1 : B_BY ]->(p : plant) return m, r1, p limit 10 ;]; A result was returned when none was expected.; nested exception is org.postgresql.util.PSQLException: A result was returned when none was expected., SQL Code->0100E

But the above query works without the optional keyword MATCH (m : mat )-[ r1 : B_BY ]->(p : plant) return m, r1, p limit 10

[bylee5]

Could you explain the execution environment? Does it occur in AgensBrowser?

[VinACE]

~> agens b_c agens (AgensGraph 1.4devel, based on PostgreSQL 10.3) Is this what you are asking for, Also Iam running the queries in agens browser -- this one gave the below error again A result was returned when none was expected.; nested exception is org.postgresql.util.PSQLException: A result was returned when none was expected., SQL Code->0100E

but the same query worked in the terminal..

[bylee5]

It appears to be an AgensBrowser bug rather than an AgensGraph.

[watery]

I'm getting the same, in the browser, where a simple:

optional match (a)-[r]-() return *;

gives the above mentioned error, while the command line client returns:

postgres=# optional match (a)-[r]-() return *;
                             a                             |              r
-----------------------------------------------------------+-----------------------------
 source_type[10.1]{"name": "clients-list"}                 | type[14.1][13.1,10.1]{}
 source_type[10.1]{"name": "clients-list"}                 | depends[12.1][10.5,10.1]{}
 ...
 source_type[10.2]{"name": "products-list"}                | depends[12.9][10.6,10.2]{}
 source_type[10.2]{"name": "products-list"}                | depends[12.11][10.3,10.2]{}
 ...
 source_type[10.3]{"name": "product-details"}              | type[14.4][13.5,10.3]{}
 source_type[10.3]{"name": "product-details"}              | depends[12.12][10.3,10.5]{}
 ...
(28 rows)

Moreover, if I remove the optional keyword from the query on the CLI client, I get the exact same rows in result and the browser is able to draw the corresponding graph. Hence I expect the latter to be able to show the graph when the query has the optional keyword too.

AgensGraph 2.1.3 AgensBrowser 1.0

[watery]

I don't know if this is related, but I get the same error running (in the browser):

match(a) return a;

while everything is fine for (notice the missing space between the match keyword and the opening parenthesis):

match (a) return a;

Of course they both give the same result when run from the command line.

So maybe there's an issue handling the keywords optional and match during query parsing?