import (
"context"
"fmt"
"io"
"regexp"
database "cloud.google.com/go/spanner/admin/database/apiv1"
adminpb "google.golang.org/genproto/googleapis/spanner/admin/database/v1"
)
func createDatabaseWithPropertyGraph(ctx context.Context, w io.Writer, dbId string) error {
// dbId is of the form:
// projects/YOUR_PROJECT_ID/instances/YOUR_INSTANCE_ID/databases/YOUR_DATABASE_NAME
matches := regexp.MustCompile("^(.*)/databases/(.*)$").FindStringSubmatch(dbId)
if matches == nil || len(matches) != 3 {
return fmt.Errorf("Invalid database id %s", dbId)
}
adminClient, err := database.NewDatabaseAdminClient(ctx)
if err != nil {
return err
}
defer adminClient.Close()
var instance = matches[1]
var dbName = matches[2]
// The schema defintion for a database with a property graph comprises table
// definitions one or more `CREATE PROPERTY GRAPH` statements to define the
// property graph(s).
//
// Here, tables are created for 'Person's and 'Account's. The property graph
// definition says that these entities form nodes in the graph. Similarly,
// there are 'PersonOwnAccount' and 'AccountTransferAccount' relationship
// tables defined. The property graph definition maps these to edges in the graph.
var schema_statements = []string{
`CREATE TABLE Person (
id INT64 NOT NULL,
name STRING(MAX),
birthday TIMESTAMP,
country STRING(MAX),
city STRING(MAX),
) PRIMARY KEY (id)`,
`CREATE TABLE Account (
id INT64 NOT NULL,
create_time TIMESTAMP,
is_blocked BOOL,
nick_name STRING(MAX),
) PRIMARY KEY (id)`,
`CREATE TABLE PersonOwnAccount (
id INT64 NOT NULL,
account_id INT64 NOT NULL,
create_time TIMESTAMP,
FOREIGN KEY (account_id)
REFERENCES Account (id)
) PRIMARY KEY (id, account_id),
INTERLEAVE IN PARENT Person ON DELETE CASCADE`,
`CREATE TABLE AccountTransferAccount (
id INT64 NOT NULL,
to_id INT64 NOT NULL,
amount FLOAT64,
create_time TIMESTAMP NOT NULL,
order_number STRING(MAX),
FOREIGN KEY (to_id) REFERENCES Account (id)
) PRIMARY KEY (id, to_id, create_time),
INTERLEAVE IN PARENT Account ON DELETE CASCADE`,
`CREATE OR REPLACE PROPERTY GRAPH FinGraph
NODE TABLES (Account, Person)
EDGE TABLES (
PersonOwnAccount
SOURCE KEY(id) REFERENCES Person(id)
DESTINATION KEY(account_id) REFERENCES Account(id)
LABEL Owns,
AccountTransferAccount
SOURCE KEY(id) REFERENCES Account(id)
DESTINATION KEY(to_id) REFERENCES Account(id)
LABEL Transfers)`,
}
op, err := adminClient.CreateDatabase(ctx, &adminpb.CreateDatabaseRequest{
Parent: instance,
CreateStatement: "CREATE DATABASE `" + dbName + "`",
ExtraStatements: schema_statements,
})
if err != nil {
return err
}
if _, err := op.Wait(ctx); err != nil {
return err
}
fmt.Fprintf(w, "Created database [%s]\n", dbId)
return nil
}
