yscan

Documentation

Overview

Package `ydbscan` allows scanning data into Go structs and other composite types, when working with `ydb` library native interface.

Essentially, `ydbscan` is a wrapper around github.com/georgysavva/scany/v2/dbscan package. ydbscan connects github.com/ydb-platform/ydb-go-sdk native interface with dbscan functionality. It contains adapters that are meant to work with result.BaseResult and proxy all calls to dbscan. ydbscan provides all capabilities available in dbscan.

Querying rows

`ydbscan` can query rows and work with table.TransactionActor, table.Session directly. To support this it has two high-level functions Select & Get.

`ydbscan` only works with `github.com/ydb-platform/ydb-go-sdk/v3`. So the import path of your ydb must be: "github.com/ydb-platform/ydb-go-sdk/v3".

Index

• Variables
• func NewDBScanAPI(opts ...dbscan.APIOption) (*dbscan.API, error)
• func ScanRow(dst any, result result.Result) error
• type API
  • func NewAPI(dbscanAPI *dbscan.API) (*API, error)
  • func (a *API) Get(ctx context.Context, tx *table.TransactionControl, db SessionQuerier, dst any, ...) (table.Transaction, error)
  • func (a *API) GetTx(ctx context.Context, db TransactionQuerier, dst any, query string, ...) error
  • func (a *API) NewRowScanner(rows result.BaseResult) *RowScanner
  • func (a *API) ScanAll(dst any, result result.BaseResult) error
  • func (a *API) ScanOne(dst any, result result.BaseResult) error
  • func (a *API) ScanRow(dst any, rows result.BaseResult) error
  • func (a *API) Select(ctx context.Context, tx *table.TransactionControl, db SessionQuerier, dst any, ...) (table.Transaction, error)
  • func (a *API) SelectTx(ctx context.Context, db TransactionQuerier, dst any, query string, ...) error
• type RowScanner
  • func NewRowScanner(result result.Result) *RowScanner
• type RowsAdapter
  • func NewRowsAdapter(result result.BaseResult) *RowsAdapter
  • func (ra RowsAdapter) Close() error
  • func (ra RowsAdapter) Columns() ([]string, error)
  • func (ra RowsAdapter) Err() error
  • func (ra RowsAdapter) Next() bool
  • func (ra RowsAdapter) Scan(dest ...any) error
• type SessionQuerier
• type TransactionQuerier

Variables

var DefaultAPI = mustNewAPI(mustNewDBScanAPI())

DefaultAPI is the default instance of API with all configuration settings set to default.

var (
	// ErrNoRows occurs when rows are expected but none are returned.
	ErrNoRows = errors.New("no rows in result set")
)

Functions

func NewDBScanAPI

func NewDBScanAPI(opts ...dbscan.APIOption) (*dbscan.API, error)

NewDBScanAPI creates a new dbscan API object with default configuration settings for pgxscan.

func ScanRow

func ScanRow(dst any, result result.Result) error

ScanRow is a package-level helper function that uses the DefaultAPI object. See API.ScanRow for details.

Types

type API

type API struct {
	// contains filtered or unexported fields
}

API is a wrapper around the dbscan.API type. See dbscan.API for details.

func NewAPI

func NewAPI(dbscanAPI *dbscan.API) (*API, error)

NewAPI creates new API instance from dbscan.API instance.

func (*API) Get

func (a *API) Get(ctx context.Context, tx *table.TransactionControl, db SessionQuerier, dst any, query string, params *table.QueryParameters) (table.Transaction, error)

Get is a high-level function that queries rows from Querier and calls the ScanOne function. See ScanOne for details.

func (*API) GetTx

func (a *API) GetTx(ctx context.Context, db TransactionQuerier, dst any, query string, params *table.QueryParameters) error

GetTx is a high-level function that queries rows from Querier and calls the ScanOne function. See ScanOne for details.

func (*API) NewRowScanner

func (a *API) NewRowScanner(rows result.BaseResult) *RowScanner

NewRowScanner returns a new RowScanner instance.

func (*API) ScanAll

func (a *API) ScanAll(dst any, result result.BaseResult) error

ScanAll is a wrapper around the dbscan.ScanAll function. See dbscan.ScanAll for details.

func (*API) ScanOne

func (a *API) ScanOne(dst any, result result.BaseResult) error

ScanOne is a wrapper around the dbscan.ScanOne function. See dbscan.ScanOne for details. If no rows are found it returns a pgx.ErrNoRows error.

func (*API) ScanRow

func (a *API) ScanRow(dst any, rows result.BaseResult) error

ScanRow is a wrapper around the dbscan.ScanRow function. See dbscan.ScanRow for details.

func (*API) Select

func (a *API) Select(ctx context.Context, tx *table.TransactionControl, db SessionQuerier, dst any, query string, params *table.QueryParameters) (table.Transaction, error)

Select is a high-level function that queries rows from Querier and calls the ScanAll function. See ScanAll for details.

func (*API) SelectTx

func (a *API) SelectTx(ctx context.Context, db TransactionQuerier, dst any, query string, params *table.QueryParameters) error

SelectTx is a high-level function that queries rows from Querier and calls the ScanAll function. See ScanAll for details.

type RowScanner

type RowScanner struct {
	*dbscan.RowScanner
}

RowScanner is a wrapper around the dbscan.RowScanner type. See dbscan.RowScanner for details.

func NewRowScanner

func NewRowScanner(result result.Result) *RowScanner

NewRowScanner is a package-level helper function that uses the DefaultAPI object. See API.NewRowScanner for details.

type RowsAdapter

type RowsAdapter struct {
	// contains filtered or unexported fields
}

RowsAdapter makes pgx.Rows compliant with the dbscan.Rows interface. See dbscan.Rows for details.

func NewRowsAdapter

func NewRowsAdapter(result result.BaseResult) *RowsAdapter

NewRowsAdapter returns a new RowsAdapter instance.

func (RowsAdapter) Close

func (ra RowsAdapter) Close() error

Close implements the dbscan.Rows.Close method.

func (RowsAdapter) Columns

func (ra RowsAdapter) Columns() ([]string, error)

Columns implements the dbscan.Rows.Columns method.

func (RowsAdapter) Err

func (ra RowsAdapter) Err() error

Err return scanner error To handle errors, do not need to check after scanning each row It is enough to check after reading all Set

func (RowsAdapter) Next

func (ra RowsAdapter) Next() bool

Next selects row in the current result set. It returns false if there are no more rows in the result set.

func (RowsAdapter) Scan

func (ra RowsAdapter) Scan(dest ...any) error

Scan scans row with column names defined in namedValues

type SessionQuerier

type SessionQuerier interface {
	Execute(
		ctx context.Context,
		tx *table.TransactionControl,
		query string,
		params *table.QueryParameters,
		opts ...options.ExecuteDataQueryOption,
	) (table.Transaction, result.Result, error)
}

SessionQuerier is an interface that is implemented by table.Session.

type TransactionQuerier

type TransactionQuerier interface {
	Execute(
		ctx context.Context,
		query string,
		params *table.QueryParameters,
		opts ...options.ExecuteDataQueryOption,
	) (result.Result, error)
}

TransactionQuerier is an interface that is implemented by table.TransactionActor.