Query data in a graph

voidQueryData(google::cloud::spanner::Clientclient){
namespacespanner=::google::cloud::spanner;
spanner::SqlStatementselect(R"""(
 Graph FinGraph
 MATCH (a:Person)-[o:Owns]->()-[t:Transfers]->()<-[p:Owns]-(b:Person)
 RETURN a.name AS sender,
 b.name AS receiver,
 t.amount,
 t.create_time AS transfer_at
)""");
usingRowType=
std::tuple<std::string,std::string,double,spanner::Timestamp>;
autorows=client.ExecuteQuery(std::move(select));
for(auto&row:spanner::StreamOf<RowType>(rows)){
if(!row)throwstd::move(row).status();
std::cout << "sender: " << std::get<0>(*row) << "\t";
std::cout << "receiver: " << std::get<1>(*row) << "\t";
std::cout << "amount: " << std::get<2>(*row) << "\t";
std::cout << "transfer_at: " << std::get<3>(*row) << "\n";
}
std::cout << "Query completed for [spanner_query_graph_data]\n";
}

import(
"context"
"fmt"
"io"
"time"
"cloud.google.com/go/spanner"
"google.golang.org/api/iterator"
)
funcqueryGraphData(wio.Writer,dbstring)error{
ctx:=context.Background()
client,err:=spanner.NewClient(ctx,db)
iferr!=nil{
returnerr
}
deferclient.Close()
// Execute a Spanner query statement comprising a graph query. Graph queries
// are characterized by 'MATCH' statements describing node and edge
// patterns.
//
// This statement finds entities ('Account's) owned by all 'Person's 'b' to
// which transfers have been made by entities ('Account's) owned by any
// 'Person' 'a' in the graph called 'FinGraph'. It then returns the names of
// all such 'Person's 'a' and 'b', and the amount and time of the transfer.
stmt:=spanner.Statement {SQL:`Graph FinGraph 
		 MATCH (a:Person)-[o:Owns]->()-[t:Transfers]->()<-[p:Owns]-(b:Person)
		 RETURN a.name AS sender, b.name AS receiver, t.amount, t.create_time AS transfer_at`}
iter:=client.Single ().Query(ctx,stmt)
deferiter.Stop()
// The results are returned in tabular form. Iterate over the
// result rows and print them.
for{
row,err:=iter.Next()
iferr==iterator.Done{
returnnil
}
iferr!=nil{
returnerr
}
varsender,receiverstring
varamountfloat64
vartransfer_attime.Time
iferr:=row.Columns (&sender,&receiver,&amount,&transfer_at);err!=nil{
returnerr
}
fmt.Fprintf(w,"%s %s %f %s\n",sender,receiver,amount,transfer_at.Format(time.RFC3339))
}
}

staticvoidquery(DatabaseClientdbClient){
try(ResultSetresultSet=
dbClient
.singleUse()// Execute a single query against Cloud Spanner.
.executeQuery(
Statement.of(
"Graph FinGraph MATCH"
+" (a:Person)-[o:Owns]->()-[t:Transfers]->()<-[p:Owns]-(b:Person)RETURN"
+" a.name AS sender, b.name AS receiver, t.amount, t.create_time AS"
+" transfer_at"))){
while(resultSet.next()){
System.out.printf(
"%s %s %f %s\n",
resultSet.getString(0),
resultSet.getString(1),
resultSet.getDouble(2),
resultSet.getTimestamp(3));
}
}
}

defquery_data(instance_id, database_id):
"""Queries sample data from the database using GQL."""
 spanner_client = spanner.Client()
 instance = spanner_client.instance(instance_id)
 database = instance.database(database_id)
 with database.snapshot() as snapshot:
 results = snapshot.execute_sql(
"""Graph FinGraph
 MATCH (a:Person)-[o:Owns]->()-[t:Transfers]->()<-[p:Owns]-(b:Person)
 RETURN a.name AS sender, b.name AS receiver, t.amount, t.create_time AS transfer_at"""
 )
 for row in results:
 print("sender: {}, receiver: {}, amount: {}, transfer_at: {}".format(*row))