CALL subqueries for cheat sheet (includes ON ERROR RETRY) (neo4j#1226)

Author: JPryce-Aklundh

modules/ROOT/pages/subqueries/call-subquery.adoc

@@ -50,6 +50,7 @@ The variables returned in a subquery are available to the outer scope of the enc
 In this example, the `CALL` subquery executes three times, one for each row that the xref:clauses/unwind.adoc[`UNWIND`] clause outputs.
 
 .Query
+// tag::subqueries_call_subquery_basic_example[]
 [source, cypher]
 ----
 UNWIND [0, 1, 2] AS x
@@ -58,6 +59,8 @@ CALL () {
 }
 RETURN innerReturn
 ----
+// end::subqueries_call_subquery_basic_example[]
+
 
 .Result
 [role="queryresult",options="header,footer",cols="m"]
@@ -117,6 +120,7 @@ As a result, `CALL` subqueries can help maintain optimal performance and scalabi
 In this example, a `CALL` subquery is used to xref:functions/aggregating.adoc#functions-collect[`collect`] a `LIST` containing all players who play for a particular team.
 
 .Collect a list of all players playing for a particular team
+// tag::subqueries_call_subquery_variable_scope[]
 [source, cypher]
 ----
 MATCH (t:Team)
@@ -126,6 +130,8 @@ CALL (t) {
 }
 RETURN t AS team, players
 ----
+// end::subqueries_call_subquery_variable_scope[]
+
 
 .Result
 [source, role="queryresult",options="header,footer",cols="m,2m"]
@@ -455,6 +461,7 @@ RETURN p.name AS playerName, team.name AS team
 Note that no results are returned for `Player C`, since they are not connected to any `Team` with a `PLAYS_FOR` relationship.
 
 .Query using regular `OPTIONAL CALL`
+// tag::subqueries_call_subquery_optional_call[]
 [source, cypher]
 ----
 MATCH (p:Player)
@@ -464,6 +471,7 @@ OPTIONAL CALL (p) {
 }
 RETURN p.name AS playerName, team.name AS team
 ----
+// end::subqueries_call_subquery_optional_call[]
 
 Now all `Player` nodes, regardless of whether they have any `PLAYS_FOR` relationships connected to a `Team`, are returned.
 
@@ -617,6 +625,7 @@ Call subqueries can be used to further process the results of a xref:queries/com
 This example query finds the youngest and the oldest `Player` in the graph.
 
 .Find the oldest and youngest players
+// tag::subqueries_call_subquery_optional_union[]
 [source, cypher]
 ----
 CALL () {
@@ -632,6 +641,7 @@ UNION
 }
 RETURN p.name AS playerName, p.age AS age
 ----
+// end::subqueries_call_subquery_optional_union[]
 
 .Result
 [role="queryresult",options="header,footer",cols="2*<m"]

modules/ROOT/pages/subqueries/subqueries-in-transactions.adoc

@@ -46,13 +46,16 @@ It creates nodes in separate transactions using `CALL { ... } IN TRANSACTIONS`:
 ----
 
 .Query
+// tag::subqueries_in_transactions_basic_example[]
 [source, cypher]
 ----
 LOAD CSV FROM 'file:///friends.csv' AS line
 CALL (line) {
   CREATE (:Person {name: line[1], age: toInteger(line[2])})
 } IN TRANSACTIONS
 ----
+// end::subqueries_in_transactions_basic_example[]
+
 
 .Result
 [role="queryresult",options="footer",cols="1*<m"]
@@ -154,13 +157,15 @@ This example loads a CSV file with one transaction for every `2` input rows:
 ----
 
 .Query
+// tag::subqueries_in_transactions_batching[]
 [source, cypher]
 ----
 LOAD CSV FROM 'file:///friends.csv' AS line
 CALL (line) {
   CREATE (:Person {name: line[1], age: toInteger(line[2])})
 } IN TRANSACTIONS OF 2 ROWS
 ----
+// end::subqueries_in_transactions_batching[]
 
 .Result
 [role="queryresult",options="footer",cols="1*<m"]
@@ -370,6 +375,7 @@ RETURN e.num
 In the following example, `ON ERROR CONTINUE` is used after a failed inner transaction to execute the remaining inner transactions and not fail the outer transaction:
 
 .Transactions batched in 1 row with `ON ERROR CONTINUE`
+// tag::subqueries_in_transactions_error_behavior[]
 [source, cypher]
 ----
 UNWIND [1, 0, 2, 4] AS i
@@ -381,6 +387,8 @@ CALL (i) {
   ON ERROR CONTINUE
 RETURN n.num
 ----
+// end::subqueries_in_transactions_error_behavior[]
+
 
 .Result
 [role="queryresult",options="header,footer",cols="1*<m"]
@@ -788,6 +796,8 @@ If a negative number is specified (which can only be done through a parameter),
 `CALL { ... } IN CONCURRENT TRANSACTIONS` is particularly suitable for importing data without dependencies.
 This example creates `Person` nodes from a unique `tmdbId` value assigned to each person row in the CSV file (444 in total) in 3 concurrent transactions.
 
+.`CALL` subquery run in `CONCURRENT TRANSACTIONS`
+// tag::subqueries_in_transactions_concurrent_transactions[]
 [source, cypher]
 ----
 LOAD CSV WITH HEADERS FROM 'https://data.neo4j.com/importing-cypher/persons.csv' AS row
@@ -797,6 +807,7 @@ CALL (row) {
 } IN 3 CONCURRENT TRANSACTIONS OF 10 ROWS
 RETURN count(*) AS personNodes
 ----
+// end::subqueries_in_transactions_concurrent_transactions[]
 
 .Result
 [role="queryresult",options="header,footer",cols="m"]
@@ -936,6 +947,7 @@ To retry the any failed inner transactions, use the error option `ON ERROR RETRY
 The following query uses `ON ERROR RETRY ... THEN CONTINUE` to retry the above query for a maximum of `3` seconds and then continue the execution of subsequent inner transactions by ignoring any recoverable errors.
 
 .Query using `ON ERROR RETRY ... THEN CONTINUE` to retry deadlocked inner transactions and complete outer transaction
+// tag::subqueries_in_transactions_deadlock_example[]
 [source, cypher]
 ----
 LOAD CSV WITH HEADERS FROM 'https://data.neo4j.com/importing-cypher/movies.csv' AS row
@@ -946,6 +958,7 @@ CALL (row) {
 } IN 2 CONCURRENT TRANSACTIONS OF 10 ROWS ON ERROR RETRY FOR 3 SECONDS THEN CONTINUE REPORT STATUS AS status
 RETURN status.transactionID as transaction, status.committed AS successfulTransaction
 ----
+// end::subqueries_in_transactions_deadlock_example[]
 
 The result shows that all transactions are now successful: