1) query parameters cannot be used in the same way in syntax v2
This is valid in syntax v1 but gives an error in v2:
[CREATE QUERY HelloWorld2(string vType) FOR GRAPH Entellect syntax v2 { ]
CREATE QUERY HelloWorld2(string vType) FOR GRAPH Entellect {
ListAccum<string> @@test;
start = {vType.*}; // *v2 has an error here: undefined vertex type used as seed*
test = select n from start:s -(Any:e)- :n ;
}
2) some functions don’t work in v2
Assuming there is a vertex type of vtype and a particular vertex has a string property of name that is nullable the following works in syntax v1 but gives an error in syntax v2.
start = {vType.*};
test = select n from start:s -(Any:e)- :n
Accum @@test += coalesce(n.Name, "N/A"); // error no type can be inferred for coalesce(n.name, "N/A"
To your first point, when you use a STRING variable as the vertex set initializer, you do not need the period or star symbols afterward.
For instance, if Topic is a vertex type in my schema:
CREATE QUERY test() FOR GRAPH MyGraph {
start = {Topic.*};
print start;
}
// Gets all Topic vertices
should function the same as
CREATE QUERY test(STRING vType) FOR GRAPH MyGraph {
start = {vType};
print start;
}
// Now, call this query with argument "Topic"
// (note: query installation required, cannot interpret)
(This should work for both syntax v1 and v2)
Hi @Leo_Shestakov , regarding your point for SYNTAX V2, its working fine without .* and installing query but only print or basic functions like start.size() is working. when i use below code, it throws error , what I am doing wrong.
CREATE DISTRIBUTED QUERY z_dynamic_syntax_v2 (STRING vType) //parameterized schema
FOR GRAPH ABC SYNTAX V2
{
SumAccum @@Vertex_CNT = 0;
start = {vType}; //no error after removing period & star symbols.
print vType, start.size(); ///working fine as expected
result = select s from start:s where s.Status==“Active” ACCUM @@Vertex_CNT+=1;
// FROM keyword(highlighted in red) is showing warning as “unsatisfiable FROM pattern, query result always empty” & start(highlighted in yellow) shows error "unsatisfiable pattern start"
PRINT @@Vertex_CNT as Total_Number_of_records;
}
Hi Ankita,
Do all of your vertex types have an attribute called Status? Since the vertex type input is dynamic, the traversal needs to be valid for all possible inputs. If not all of your vertices have a Status attribute, then you can use an IF or CASE statement to ensure you’re only looking for Status on vertices that have a Status attribute.
@Dan_Barkus , Thanks for your response.
I have removed where clause for Status column but still I am getting same warning at START & FROM keywords. is that not supported in SYNTAX V2?
Can you share any sample query where its working, Its very basic query to store count in accumulator & print but not using size() function. we want to achieve it using “select” query.
