bigquery/table.go - gocloud - Git at Google

 // Copyright 2015 Google Inc. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //      http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 package bigquery

 import (
 	"fmt"
 	"time"

 	"golang.org/x/net/context"

 	"cloud.google.com/go/internal/optional"
 	bq "google.golang.org/api/bigquery/v2"
 )

 // A Table is a reference to a BigQuery table.
 type Table struct {
 	// ProjectID, DatasetID and TableID may be omitted if the Table is the destination for a query.
 	// In this case the result will be stored in an ephemeral table.
 	ProjectID string
 	DatasetID string
 	// TableID must contain only letters (a-z, A-Z), numbers (0-9), or underscores (_).
 	// The maximum length is 1,024 characters.
 	TableID string

 	c *Client
 }

 // TableMetadata contains information about a BigQuery table.
 type TableMetadata struct {
 	// The following fields can be set when creating a table.

 	// The user-friendly name for the table.
 	Name string

 	// The user-friendly description of the table.
 	Description string

 	// The table schema. If provided on create, ViewQuery must be empty.
 	Schema Schema

 	// The query to use for a view. If provided on create, Schema must be nil.
 	ViewQuery string

 	// Use Legacy SQL for the view query.
 	// At most one of UseLegacySQL and UseStandardSQL can be true.
 	UseLegacySQL bool

 	// Use Legacy SQL for the view query. The default.
 	// At most one of UseLegacySQL and UseStandardSQL can be true.
 	UseStandardSQL bool

 	// If non-nil, the table is partitioned by time.
 	TimePartitioning *TimePartitioning

 	// The time when this table expires. If not set, the table will persist
 	// indefinitely. Expired tables will be deleted and their storage reclaimed.
 	ExpirationTime time.Time

 	// All the fields below are read-only.

 	FullID           string // An opaque ID uniquely identifying the table.
 	Type             TableType
 	CreationTime     time.Time
 	LastModifiedTime time.Time

 	// The size of the table in bytes.
 	// This does not include data that is being buffered during a streaming insert.
 	NumBytes int64

 	// The number of rows of data in this table.
 	// This does not include data that is being buffered during a streaming insert.
 	NumRows uint64

 	// Contains information regarding this table's streaming buffer, if one is
 	// present. This field will be nil if the table is not being streamed to or if
 	// there is no data in the streaming buffer.
 	StreamingBuffer *StreamingBuffer

 	// ETag is the ETag obtained when reading metadata. Pass it to Table.Update to
 	// ensure that the metadata hasn't changed since it was read.
 	ETag string
 }

 // TableCreateDisposition specifies the circumstances under which destination table will be created.
 // Default is CreateIfNeeded.
 type TableCreateDisposition string

 const (
 	// CreateIfNeeded will create the table if it does not already exist.
 	// Tables are created atomically on successful completion of a job.
 	CreateIfNeeded TableCreateDisposition = "CREATE_IF_NEEDED"

 	// CreateNever ensures the table must already exist and will not be
 	// automatically created.
 	CreateNever TableCreateDisposition = "CREATE_NEVER"
 )

 // TableWriteDisposition specifies how existing data in a destination table is treated.
 // Default is WriteAppend.
 type TableWriteDisposition string

 const (
 	// WriteAppend will append to any existing data in the destination table.
 	// Data is appended atomically on successful completion of a job.
 	WriteAppend TableWriteDisposition = "WRITE_APPEND"

 	// WriteTruncate overrides the existing data in the destination table.
 	// Data is overwritten atomically on successful completion of a job.
 	WriteTruncate TableWriteDisposition = "WRITE_TRUNCATE"

 	// WriteEmpty fails writes if the destination table already contains data.
 	WriteEmpty TableWriteDisposition = "WRITE_EMPTY"
 )

 // TableType is the type of table.
 type TableType string

 const (
 	RegularTable  TableType = "TABLE"
 	ViewTable     TableType = "VIEW"
 	ExternalTable TableType = "EXTERNAL"
 )

 // TimePartitioning describes the time-based date partitioning on a table.
 // For more information see: https://cloud.google.com/bigquery/docs/creating-partitioned-tables.
 type TimePartitioning struct {
 	// The amount of time to keep the storage for a partition.
 	// If the duration is empty (0), the data in the partitions do not expire.
 	Expiration time.Duration
 }

 // StreamingBuffer holds information about the streaming buffer.
 type StreamingBuffer struct {
 	// A lower-bound estimate of the number of bytes currently in the streaming
 	// buffer.
 	EstimatedBytes uint64

 	// A lower-bound estimate of the number of rows currently in the streaming
 	// buffer.
 	EstimatedRows uint64

 	// The time of the oldest entry in the streaming buffer.
 	OldestEntryTime time.Time
 }

 func (t *Table) tableRefProto() *bq.TableReference {
 	return &bq.TableReference{
 		ProjectId: t.ProjectID,
 		DatasetId: t.DatasetID,
 		TableId:   t.TableID,
 	}
 }

 // FullyQualifiedName returns the ID of the table in projectID:datasetID.tableID format.
 func (t *Table) FullyQualifiedName() string {
 	return fmt.Sprintf("%s:%s.%s", t.ProjectID, t.DatasetID, t.TableID)
 }

 // implicitTable reports whether Table is an empty placeholder, which signifies that a new table should be created with an auto-generated Table ID.
 func (t *Table) implicitTable() bool {
 	return t.ProjectID == "" && t.DatasetID == "" && t.TableID == ""
 }

 // Create creates a table in the BigQuery service.
 // Pass in a TableMetadata value to configure the dataset.
 func (t *Table) Create(ctx context.Context, tm *TableMetadata) error {
 	return t.c.service.createTable(ctx, t.ProjectID, t.DatasetID, t.TableID, tm)
 }

 // Metadata fetches the metadata for the table.
 func (t *Table) Metadata(ctx context.Context) (*TableMetadata, error) {
 	return t.c.service.getTableMetadata(ctx, t.ProjectID, t.DatasetID, t.TableID)
 }

 // Delete deletes the table.
 func (t *Table) Delete(ctx context.Context) error {
 	return t.c.service.deleteTable(ctx, t.ProjectID, t.DatasetID, t.TableID)
 }

 // Read fetches the contents of the table.
 func (t *Table) Read(ctx context.Context) *RowIterator {
 	return newRowIterator(ctx, t.c.service, &readTableConf{
 		projectID: t.ProjectID,
 		datasetID: t.DatasetID,
 		tableID:   t.TableID,
 	})
 }

 // Update modifies specific Table metadata fields.
 func (t *Table) Update(ctx context.Context, tm TableMetadataToUpdate, etag string) (*TableMetadata, error) {
 	var conf patchTableConf
 	if tm.Description != nil {
 		s := optional.ToString(tm.Description)
 		conf.Description = &s
 	}
 	if tm.Name != nil {
 		s := optional.ToString(tm.Name)
 		conf.Name = &s
 	}
 	conf.Schema = tm.Schema
 	conf.ExpirationTime = tm.ExpirationTime
 	return t.c.service.patchTable(ctx, t.ProjectID, t.DatasetID, t.TableID, &conf, etag)
 }

 // TableMetadataToUpdate is used when updating a table's metadata.
 // Only non-nil fields will be updated.
 type TableMetadataToUpdate struct {
 	// Description is the user-friendly description of this table.
 	Description optional.String

 	// Name is the user-friendly name for this table.
 	Name optional.String

 	// Schema is the table's schema.
 	// When updating a schema, you can add columns but not remove them.
 	Schema Schema
 	// TODO(jba): support updating the view

 	// ExpirationTime is the time when this table expires.
 	ExpirationTime time.Time
 }
	// Copyright 2015 Google Inc. All Rights Reserved.
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	package bigquery

	import (
	"fmt"
	"time"

	"golang.org/x/net/context"

	"cloud.google.com/go/internal/optional"
	bq "google.golang.org/api/bigquery/v2"
	)

	// A Table is a reference to a BigQuery table.
	type Table struct {
	// ProjectID, DatasetID and TableID may be omitted if the Table is the destination for a query.
	// In this case the result will be stored in an ephemeral table.
	ProjectID string
	DatasetID string
	// TableID must contain only letters (a-z, A-Z), numbers (0-9), or underscores (_).
	// The maximum length is 1,024 characters.
	TableID string

	c *Client
	}

	// TableMetadata contains information about a BigQuery table.
	type TableMetadata struct {
	// The following fields can be set when creating a table.

	// The user-friendly name for the table.
	Name string

	// The user-friendly description of the table.
	Description string

	// The table schema. If provided on create, ViewQuery must be empty.
	Schema Schema

	// The query to use for a view. If provided on create, Schema must be nil.
	ViewQuery string

	// Use Legacy SQL for the view query.
	// At most one of UseLegacySQL and UseStandardSQL can be true.
	UseLegacySQL bool

	// Use Legacy SQL for the view query. The default.
	// At most one of UseLegacySQL and UseStandardSQL can be true.
	UseStandardSQL bool

	// If non-nil, the table is partitioned by time.
	TimePartitioning *TimePartitioning

	// The time when this table expires. If not set, the table will persist
	// indefinitely. Expired tables will be deleted and their storage reclaimed.
	ExpirationTime time.Time

	// All the fields below are read-only.

	FullID string // An opaque ID uniquely identifying the table.
	Type TableType
	CreationTime time.Time
	LastModifiedTime time.Time

	// The size of the table in bytes.
	// This does not include data that is being buffered during a streaming insert.
	NumBytes int64

	// The number of rows of data in this table.
	// This does not include data that is being buffered during a streaming insert.
	NumRows uint64

	// Contains information regarding this table's streaming buffer, if one is
	// present. This field will be nil if the table is not being streamed to or if
	// there is no data in the streaming buffer.
	StreamingBuffer *StreamingBuffer

	// ETag is the ETag obtained when reading metadata. Pass it to Table.Update to
	// ensure that the metadata hasn't changed since it was read.
	ETag string
	}

	// TableCreateDisposition specifies the circumstances under which destination table will be created.
	// Default is CreateIfNeeded.
	type TableCreateDisposition string

	const (
	// CreateIfNeeded will create the table if it does not already exist.
	// Tables are created atomically on successful completion of a job.
	CreateIfNeeded TableCreateDisposition = "CREATE_IF_NEEDED"

	// CreateNever ensures the table must already exist and will not be
	// automatically created.
	CreateNever TableCreateDisposition = "CREATE_NEVER"
	)

	// TableWriteDisposition specifies how existing data in a destination table is treated.
	// Default is WriteAppend.
	type TableWriteDisposition string

	const (
	// WriteAppend will append to any existing data in the destination table.
	// Data is appended atomically on successful completion of a job.
	WriteAppend TableWriteDisposition = "WRITE_APPEND"

	// WriteTruncate overrides the existing data in the destination table.
	// Data is overwritten atomically on successful completion of a job.
	WriteTruncate TableWriteDisposition = "WRITE_TRUNCATE"

	// WriteEmpty fails writes if the destination table already contains data.
	WriteEmpty TableWriteDisposition = "WRITE_EMPTY"
	)

	// TableType is the type of table.
	type TableType string

	const (
	RegularTable TableType = "TABLE"
	ViewTable TableType = "VIEW"
	ExternalTable TableType = "EXTERNAL"
	)

	// TimePartitioning describes the time-based date partitioning on a table.
	// For more information see: https://cloud.google.com/bigquery/docs/creating-partitioned-tables.
	type TimePartitioning struct {
	// The amount of time to keep the storage for a partition.
	// If the duration is empty (0), the data in the partitions do not expire.
	Expiration time.Duration
	}

	// StreamingBuffer holds information about the streaming buffer.
	type StreamingBuffer struct {
	// A lower-bound estimate of the number of bytes currently in the streaming
	// buffer.
	EstimatedBytes uint64

	// A lower-bound estimate of the number of rows currently in the streaming
	// buffer.
	EstimatedRows uint64

	// The time of the oldest entry in the streaming buffer.
	OldestEntryTime time.Time
	}

	func (t Table) tableRefProto() bq.TableReference {
	return &bq.TableReference{
	ProjectId: t.ProjectID,
	DatasetId: t.DatasetID,
	TableId: t.TableID,
	}
	}

	// FullyQualifiedName returns the ID of the table in projectID:datasetID.tableID format.
	func (t *Table) FullyQualifiedName() string {
	return fmt.Sprintf("%s:%s.%s", t.ProjectID, t.DatasetID, t.TableID)
	}

	// implicitTable reports whether Table is an empty placeholder, which signifies that a new table should be created with an auto-generated Table ID.
	func (t *Table) implicitTable() bool {
	return t.ProjectID == "" && t.DatasetID == "" && t.TableID == ""
	}

	// Create creates a table in the BigQuery service.
	// Pass in a TableMetadata value to configure the dataset.
	func (t Table) Create(ctx context.Context, tm TableMetadata) error {
	return t.c.service.createTable(ctx, t.ProjectID, t.DatasetID, t.TableID, tm)
	}

	// Metadata fetches the metadata for the table.
	func (t Table) Metadata(ctx context.Context) (TableMetadata, error) {
	return t.c.service.getTableMetadata(ctx, t.ProjectID, t.DatasetID, t.TableID)
	}

	// Delete deletes the table.
	func (t *Table) Delete(ctx context.Context) error {
	return t.c.service.deleteTable(ctx, t.ProjectID, t.DatasetID, t.TableID)
	}

	// Read fetches the contents of the table.
	func (t Table) Read(ctx context.Context) RowIterator {
	return newRowIterator(ctx, t.c.service, &readTableConf{
	projectID: t.ProjectID,
	datasetID: t.DatasetID,
	tableID: t.TableID,
	})
	}

	// Update modifies specific Table metadata fields.
	func (t Table) Update(ctx context.Context, tm TableMetadataToUpdate, etag string) (TableMetadata, error) {
	var conf patchTableConf
	if tm.Description != nil {
	s := optional.ToString(tm.Description)
	conf.Description = &s
	}
	if tm.Name != nil {
	s := optional.ToString(tm.Name)
	conf.Name = &s
	}
	conf.Schema = tm.Schema
	conf.ExpirationTime = tm.ExpirationTime
	return t.c.service.patchTable(ctx, t.ProjectID, t.DatasetID, t.TableID, &conf, etag)
	}

	// TableMetadataToUpdate is used when updating a table's metadata.
	// Only non-nil fields will be updated.
	type TableMetadataToUpdate struct {
	// Description is the user-friendly description of this table.
	Description optional.String

	// Name is the user-friendly name for this table.
	Name optional.String

	// Schema is the table's schema.
	// When updating a schema, you can add columns but not remove them.
	Schema Schema
	// TODO(jba): support updating the view

	// ExpirationTime is the time when this table expires.
	ExpirationTime time.Time
	}