기본 스트림을 사용하여 복잡한 데이터를 테이블에 추가하는 방법을 보여줍니다.
코드 샘플
Go
이 샘플을 사용해 보기 전에 BigQuery 빠른 시작: 클라이언트 라이브러리 사용의 Go 설정 안내를 따르세요. 자세한 내용은 BigQuery Go API 참고 문서를 확인하세요.
BigQuery에 인증하려면 애플리케이션 기본 사용자 인증 정보를 설정합니다. 자세한 내용은 클라이언트 라이브러리의 인증 설정을 참조하세요.
import (
"context"
"fmt"
"io"
"math/rand"
"time"
"cloud.google.com/go/bigquery/storage/managedwriter"
"cloud.google.com/go/bigquery/storage/managedwriter/adapt"
"github.com/GoogleCloudPlatform/golang-samples/bigquery/snippets/managedwriter/exampleproto"
"google.golang.org/protobuf/proto"
)
// generateExampleMessages generates a slice of serialized protobuf messages using a statically defined
// and compiled protocol buffer file, and returns the binary serialized representation.
func generateExampleDefaultMessages(numMessages int) ([][]byte, error) {
msgs := make([][]byte, numMessages)
for i := 0; i < numMessages; i++ {
// instantiate a new random source.
random := rand.New(
rand.NewSource(time.Now().UnixNano()),
)
// Our example data embeds an array of structs, so we'll construct that first.
sl := make([]*exampleproto.SampleStruct, 5)
for i := 0; i < int(random.Int63n(5)+1); i++ {
sl[i] = &exampleproto.SampleStruct{
SubIntCol: proto.Int64(random.Int63()),
}
}
m := &exampleproto.SampleData{
BoolCol: proto.Bool(true),
BytesCol: []byte("some bytes"),
Float64Col: proto.Float64(3.14),
Int64Col: proto.Int64(123),
StringCol: proto.String("example string value"),
// These types require special encoding/formatting to transmit.
// DATE values are number of days since the Unix epoch.
DateCol: proto.Int32(int32(time.Now().UnixNano() / 86400000000000)),
// DATETIME uses the literal format.
DatetimeCol: proto.String("2022-01-01 12:13:14.000000"),
// GEOGRAPHY uses Well-Known-Text (WKT) format.
GeographyCol: proto.String("POINT(-122.350220 47.649154)"),
// NUMERIC and BIGNUMERIC can be passed as string, or more efficiently
// using a packed byte representation.
NumericCol: proto.String("99999999999999999999999999999.999999999"),
BignumericCol: proto.String("578960446186580977117854925043439539266.34992332820282019728792003956564819967"),
// TIME also uses literal format.
TimeCol: proto.String("12:13:14.000000"),
// TIMESTAMP uses microseconds since Unix epoch.
TimestampCol: proto.Int64(time.Now().UnixNano() / 1000),
// Int64List is an array of INT64 types.
Int64List: []int64{2, 4, 6, 8},
// This is a required field in the schema, and thus must be present.
RowNum: proto.Int64(23),
// StructCol is a single nested message.
StructCol: &exampleproto.SampleStruct{
SubIntCol: proto.Int64(random.Int63()),
},
// StructList is a repeated array of a nested message.
StructList: sl,
}
b, err := proto.Marshal(m)
if err != nil {
return nil, fmt.Errorf("error generating message %d: %w", i, err)
}
msgs[i] = b
}
return msgs, nil
}
// appendToDefaultStream demonstrates using the managedwriter package to write some example data
// to a default stream.
func appendToDefaultStream(w io.Writer, projectID, datasetID, tableID string) error {
// projectID := "myproject"
// datasetID := "mydataset"
// tableID := "mytable"
ctx := context.Background()
// Instantiate a managedwriter client to handle interactions with the service.
client, err := managedwriter.NewClient(ctx, projectID,
managedwriter.WithMultiplexing(), // Enables connection sharing.
)
if err != nil {
return fmt.Errorf("managedwriter.NewClient: %w", err)
}
// Close the client when we exit the function.
defer client.Close()
// We need to communicate the descriptor of the protocol buffer message we're using, which
// is analagous to the "schema" for the message. Both SampleData and SampleStruct are
// two distinct messages in the compiled proto file, so we'll use adapt.NormalizeDescriptor
// to unify them into a single self-contained descriptor representation.
var m *exampleproto.SampleData
descriptorProto, err := adapt.NormalizeDescriptor(m.ProtoReflect().Descriptor())
if err != nil {
return fmt.Errorf("NormalizeDescriptor: %w", err)
}
// Build the formatted reference to the destination table.
tableReference := managedwriter.TableParentFromParts(projectID, datasetID, tableID)
// Instantiate a ManagedStream, which manages low level details like connection state and provides
// additional features like a future-like callback for appends, etc. Default streams are provided by
// the system, so there's no need to create them.
managedStream, err := client.NewManagedStream(ctx,
managedwriter.WithType(managedwriter.DefaultStream),
managedwriter.WithDestinationTable(tableReference),
managedwriter.WithSchemaDescriptor(descriptorProto),
)
if err != nil {
return fmt.Errorf("NewManagedStream: %w", err)
}
// Automatically close the writer when we're done.
defer managedStream.Close()
// First, we'll append a single row.
rows, err := generateExampleDefaultMessages(1)
if err != nil {
return fmt.Errorf("generateExampleMessages: %w", err)
}
// We can append data asyncronously, so we'll check our appends at the end.
var results []*managedwriter.AppendResult
result, err := managedStream.AppendRows(ctx, rows)
if err != nil {
return fmt.Errorf("AppendRows first call error: %w", err)
}
results = append(results, result)
// This time, we'll append three more rows in a single request.
rows, err = generateExampleMessages(3)
if err != nil {
return fmt.Errorf("generateExampleMessages: %w", err)
}
result, err = managedStream.AppendRows(ctx, rows)
if err != nil {
return fmt.Errorf("AppendRows second call error: %w", err)
}
results = append(results, result)
// Finally, we'll append two more rows.
rows, err = generateExampleMessages(2)
if err != nil {
return fmt.Errorf("generateExampleMessages: %w", err)
}
result, err = managedStream.AppendRows(ctx, rows)
if err != nil {
return fmt.Errorf("AppendRows third call error: %w", err)
}
results = append(results, result)
// We've been collecting references to our status callbacks to allow us to append in a faster
// asynchronous fashion. Normally you could do this in another goroutine or similar, but for
// this example we'll now iterate through those results and verify they were all successful.
for k, v := range results {
// GetResult blocks until we receive a response from the API.
recvOffset, err := v.GetResult(ctx)
if err != nil {
return fmt.Errorf("append %d returned error: %w", k, err)
}
fmt.Fprintf(w, "Successfully appended data at offset %d.\n", recvOffset)
}
// This stream is a default stream, which means it doesn't require any form of finalization
// or commit. The rows were automatically committed to the table.
return nil
}
다음 단계
다른 Google Cloud 제품의 코드 샘플을 검색하고 필터링하려면 Google Cloud 샘플 브라우저를 참조하세요.