> ## Documentation Index
> Fetch the complete documentation index at: https://gql.ch/llms.txt
> Use this file to discover all available pages before exploring further.
# CALL
CALL statement in GQL invokes a Procedure
## For each node find the number of incoming edges
Suppose we are interested in the number of highways flowing into each of the Highway:
```mermaid theme={null}
%%{init: {'theme':'base', 'themeVariables': {'lineColor':'#F1FA8C','secondaryColor':'#F1FA8C','background':'#282A36'}}}%%
graph TB
highway1(:freeway 🛣️
name: Highway 1)
highway2(:freeway 🛣️
name: Highway 2)
highway3(:freeway 🛣️
name: Highway 3)
highway4(:freeway 🛣️
name: Highway 4)
highway5(:freeway 🛣️
name: Highway 5)
highway6(:freeway 🛣️
name: Highway 6)
highway7(:freeway 🛣️
name: Highway 7)
highway8(:freeway 🛣️
name: Highway 8)
highway9(:freeway 🛣️
name: Highway 9)
highway10(:freeway 🛣️
name: Highway 10)
highway11(:freeway 🛣️
name: Highway 11)
highway12(:freeway 🛣️
name: Highway 12)
highway13(:freeway 🛣️
name: Highway 13)
highway1 -->|:links_to| highway3
highway2 -->|:links_to| highway3
highway3 -->|:links_to| highway4
highway3 -->|:links_to| highway6
highway4 -->|:links_to| highway5
highway6 -->|:links_to| highway7
highway5 -->|:links_to| highway8
highway7 -->|:links_to| highway8
highway9 -->|:links_to| highway10
highway11 -->|:links_to| highway12
highway8 -->|:links_to| highway12
highway10 -->|:links_to| highway12
highway12 -->|:links_to| highway13
classDef nodes fill:#BD93F9,stroke-width:0px
class highway1,highway2,highway3,highway4,highway5,highway6,highway7,highway8,highway9,highway10,highway11,highway12,highway13 nodes
```
We can use the CALL statement to invoke and inline procedure as follows:
```gql theme={null}
MATCH nodes = (b)
CALL {
MATCH path = (a)-[e1:flows_to]->(b)
return path
, count(distinct e1) as incoming_nodes_count
, COLLECT_LIST(distinct a.name) as incoming_nodes
}
return table(b.name, incoming_nodes_count, incoming_nodes)
order by incoming_nodes_count desc;
```
## For each node list paths to all other nodes
We are interested in getting all paths from each to all other nodes:
```mermaid theme={null}
%%{init: {'theme':'base', 'themeVariables': {'lineColor':'#F1FA8C','secondaryColor':'#F1FA8C','background':'#282A36'}}}%%
graph TB
highway1(:freeway 🛣️
name: Highway 1)
highway2(:freeway 🛣️
name: Highway 2)
highway3(:freeway 🛣️
name: Highway 3)
highway4(:freeway 🛣️
name: Highway 4)
highway5(:freeway 🛣️
name: Highway 5)
highway6(:freeway 🛣️
name: Highway 6)
highway7(:freeway 🛣️
name: Highway 7)
highway8(:freeway 🛣️
name: Highway 8)
highway9(:freeway 🛣️
name: Highway 9)
highway10(:freeway 🛣️
name: Highway 10)
highway11(:freeway 🛣️
name: Highway 11)
highway12(:freeway 🛣️
name: Highway 12)
highway13(:freeway 🛣️
name: Highway 13)
highway1 -->|:links_to| highway3
highway2 -->|:links_to| highway3
highway3 -->|:links_to| highway4
highway3 -->|:links_to| highway6
highway4 -->|:links_to| highway5
highway6 -->|:links_to| highway7
highway5 -->|:links_to| highway8
highway7 -->|:links_to| highway8
highway9 -->|:links_to| highway10
highway11 -->|:links_to| highway12
highway8 -->|:links_to| highway12
highway10 -->|:links_to| highway12
highway12 -->|:links_to| highway13
classDef nodes fill:#BD93F9,stroke-width:0px
class highway1,highway2,highway3,highway4,highway5,highway6,highway7,highway8,highway9,highway10,highway11,highway12,highway13 nodes
```
```gql theme={null}
MATCH nodes = (a)
CALL {
MATCH path = (a)-[edges:flows_to]->{0,}(b)
return reduce(path = a._id, edge in edges | path || '->' || edge._to) as route
, b
}
return table(a.name as starting, b.name as ending, route)
```
## Movie recommendations based on what the 1 degree connection and 2nd degree connection have watched
```mermaid theme={null}
%%{init: {'theme':'base', 'themeVariables': {'lineColor':'#F1FA8C','secondaryColor':'#F1FA8C','background':'#282A36'}}}%%
graph TB
subgraph row1[" "]
Maryam(:account 🧕
name: Maryam)
Sara(:account 🧕
name: Sara)
Uroosa(:account 🧕
name: Uroosa)
Fatima(:account 🧕
name: Fatima)
Zainab(:account 🧕
name: Zainab)
Hannah(:account 🧕
name: Hannah)
end
subgraph row2[" "]
despicable_me(:movie 🎬
name: Despicable Me)
penguins_of_madagascar(:movie 🎬
name: Penguins of Madagascar)
time_hoppers(:movie 🎬
name: Time Hoppers)
zootopia(:movie 🎬
name: Zootopia)
end
Sara <-->|:friend| Uroosa
Uroosa <-->|:friend| Maryam
Maryam <-->|:friend| Fatima
Zainab <-->|:friend| Hannah
Sara -->|:watched 👀| zootopia
Uroosa -->|:watched 👀| penguins_of_madagascar
Maryam -->|:watched 👀| time_hoppers
Fatima -->|:watched 👀| time_hoppers
Zainab -->|:watched 👀| time_hoppers
Fatima -->|:watched 👀| despicable_me
Hannah -->|:watched 👀| despicable_me
classDef nodes fill:#BD93F9,stroke-width:0px
class Maryam,Sara,Uroosa,Fatima,Hannah,Zainab,highway7,highway8,highway9,highway10,highway11,highway12,highway13 nodes
classDef subgraphStyle fill:#282A36, stroke-width:0px
class row1,row2,row3 subgraphStyle
```
Recommend movies based on what account 1st and 2nd degree connection have watched:
```gql theme={null}
MATCH friends = ALL (account_a)-[:friends]->{0,2}(account_b)
CALL {
MATCH path = (account_a)-[:watched]->(movie_a)
, (account_b)-[:watched]->(movie_b)
FILTER account_a <> account_b and movie_a <> movie_b
return path
, COLLECT_LIST(distinct movie_a.title) as recommended_movies
}
FILTER account_a <> account_b
return table(account_a.name, account_b.name, recommended_movies);
```