db2

Documentation

Overview

Package db2 is the replacement for db. It provides low level db connection and query capabilities.

Index

• Constants
• Variables
• type PageQuery
  • func MustPageQuery(cursor string, order string, limit uint64) PageQuery
  • func NewPageQuery(cursor string, order string, limit uint64) (result PageQuery, err error)
  • func (p PageQuery) ApplyTo(sql sq.SelectBuilder, col string) (sq.SelectBuilder, error)
  • func (p PageQuery) ApplyToUsingCursor(sql sq.SelectBuilder, col string, cursor interface{}) (sq.SelectBuilder, error)
  • func (p PageQuery) CursorInt64() (int64, error)
  • func (p PageQuery) CursorInt64Pair(sep string) (l int64, r int64, err error)
  • func (p PageQuery) GetContinuations(records interface{}) (next PageQuery, prev PageQuery, err error)
  • func (p PageQuery) Invert() PageQuery
• type Pageable

Constants

const (
	// DefaultPageSize is the default page size for db queries
	DefaultPageSize = 10
	// MaxPageSize is the max page size for db queries
	MaxPageSize = 200

	// OrderAscending is used to indicate an ascending order in request params
	OrderAscending = "asc"

	// OrderDescending is used to indicate an descending order in request params
	OrderDescending = "desc"

	// DefaultPairSep is the default separator used to separate two numbers for CursorInt64Pair
	DefaultPairSep = "-"
)

Variables

var (
	// ErrInvalidOrder is an error that occurs when a user-provided order string
	// is invalid
	ErrInvalidOrder = errors.New("Invalid order")
	// ErrInvalidLimit is an error that occurs when a user-provided limit num
	// is invalid
	ErrInvalidLimit = errors.New("Invalid limit")
	// ErrInvalidCursor is an error that occurs when a user-provided cursor string
	// is invalid
	ErrInvalidCursor = errors.New("Invalid cursor")
	// ErrNotPageable is an error that occurs when the records provided to
	// PageQuery.GetContinuations cannot be cast to Pageable
	ErrNotPageable = errors.New("Records provided are not Pageable")
)

Types

type PageQuery

type PageQuery struct {
	Cursor string
	Order  string
	Limit  uint64
}

PageQuery represents a portion of a Query struct concerned with paging through a large dataset.

func MustPageQuery

func MustPageQuery(cursor string, order string, limit uint64) PageQuery

MustPageQuery behaves as NewPageQuery, but panics upon error

func NewPageQuery

func NewPageQuery(
	cursor string,
	order string,
	limit uint64,
) (result PageQuery, err error)

NewPageQuery creates a new PageQuery struct, ensuring the order, limit, and cursor are set to the appropriate defaults and are valid.

func (PageQuery) ApplyTo

func (p PageQuery) ApplyTo(
	sql sq.SelectBuilder,
	col string,
) (sq.SelectBuilder, error)

ApplyTo returns a new SelectBuilder after applying the paging effects of `p` to `sql`. This method provides the default case for paging: int64 cursor-based paging by an id column.

func (PageQuery) ApplyToUsingCursor

func (p PageQuery) ApplyToUsingCursor(
	sql sq.SelectBuilder,
	col string,
	cursor interface{},
) (sq.SelectBuilder, error)

ApplyToUsingCursor returns a new SelectBuilder after applying the paging effects of `p` to `sql`. This method allows any type of cursor by a single column

func (PageQuery) CursorInt64

func (p PageQuery) CursorInt64() (int64, error)

CursorInt64 parses this query's Cursor string as an int64

func (PageQuery) CursorInt64Pair

func (p PageQuery) CursorInt64Pair(sep string) (l int64, r int64, err error)

CursorInt64Pair parses this query's Cursor string as two int64s, separated by the provided separator

func (PageQuery) GetContinuations

func (p PageQuery) GetContinuations(records interface{}) (next PageQuery, prev PageQuery, err error)

GetContinuations returns two new PageQuery structs, a next and previous query.

func (PageQuery) Invert

func (p PageQuery) Invert() PageQuery

Invert returns a new PageQuery whose order is reversed

type Pageable

type Pageable interface {
	PagingToken() string
}

Pageable records have a defined order, and the place withing that order is determined by the paging token