query

README

Query

Control Flow

• Grouping with ( and )
• Chaining with and and or
  • NO mixing! Be explicit and use grouping.
• Negation with not
  • in front of expression for group: not (...)
  • inside expression for clause: name not matches "^King "

Selectors

Supported by all feeders:

• root level field: field
• sub level field: field.sub
• array/slice/map access: map.0
• array/slice/map length: map.#

Please note that some feeders may have other special characters. It is advised to only use alphanumeric characters for keys.

Operators

Name	Textual	Req. Type	Internal Type	Compared with
Equals	==	int	int64	==
GreaterThan	>	int	int64	>
GreaterThanOrEqual	>=	int	int64	>=
LessThan	<	int	int64	<
LessThanOrEqual	<=	int	int64	<=
FloatEquals	f==	float	float64	==
FloatGreaterThan	f>	float	float64	>
FloatGreaterThanOrEqual	f>=	float	float64	>=
FloatLessThan	f<	float	float64	<
FloatLessThanOrEqual	f<=	float	float64	<=
SameAs	sameas, s==	string	string	==
Contains	contains, co	string	string	strings.Contains()
StartsWith	startswith, sw	string	string	strings.HasPrefix()
EndsWith	endswith, ew	string	string	strings.HasSuffix()
In	in	string	string	for loop with ==
Matches	matches, re	string	string	regexp.Regexp.Matches()
Is	is	bool*	bool	==
Exists	exists, ex	any	n/a	n/a

*accepts strings: 1, t, T, true, True, TRUE, 0, f, F, false, False, FALSE

Escaping

If you need to use a control character within a value (ie. not for controlling), escape it with \. It is recommended to wrap a word into parenthesis instead of escaping control characters, when possible.

Location	Characters to be escaped
Within parenthesis (")	", \
Everywhere else	(, ), ", \, \t, \r, \n, (space)

Documentation

Index

• Constants
• type Condition
  • func And(conditions ...Condition) Condition
  • func Not(c Condition) Condition
  • func Or(conditions ...Condition) Condition
  • func Where(key string, operator uint8, value interface{}) Condition
• type Query
  • func New(prefix string) *Query
  • func ParseQuery(query string) (*Query, error)
  • func (q *Query) Check() (*Query, error)
  • func (q *Query) DatabaseKeyPrefix() string
  • func (q *Query) DatabaseName() string
  • func (q *Query) IsChecked() bool
  • func (q *Query) Limit(limit int) *Query
  • func (q *Query) Matches(r record.Record) bool
  • func (q *Query) MatchesAccessor(acc accessor.Accessor) bool
  • func (q *Query) MatchesKey(dbKey string) bool
  • func (q *Query) MatchesRecord(r record.Record) bool
  • func (q *Query) MustBeValid() *Query
  • func (q *Query) Offset(offset int) *Query
  • func (q *Query) OrderBy(key string) *Query
  • func (q *Query) Print() string
  • func (q *Query) Where(condition Condition) *Query

Constants

const (
	Equals                  uint8 = iota // int
	GreaterThan                          // int
	GreaterThanOrEqual                   // int
	LessThan                             // int
	LessThanOrEqual                      // int
	FloatEquals                          // float
	FloatGreaterThan                     // float
	FloatGreaterThanOrEqual              // float
	FloatLessThan                        // float
	FloatLessThanOrEqual                 // float
	SameAs                               // string
	Contains                             // string
	StartsWith                           // string
	EndsWith                             // string
	In                                   // stringSlice
	Matches                              // regex
	Is                                   // bool: accepts 1, t, T, TRUE, true, True, 0, f, F, FALSE
	Exists                               // any

)

Operators.

Types

type Condition

type Condition interface {
	// contains filtered or unexported methods
}

Condition is an interface to provide a common api to all condition types.

func And

func And(conditions ...Condition) Condition

And combines multiple conditions with a logical _AND_ operator.

func Not

func Not(c Condition) Condition

Not negates the supplied condition.

func Or

func Or(conditions ...Condition) Condition

Or combines multiple conditions with a logical _OR_ operator.

func Where

func Where(key string, operator uint8, value interface{}) Condition

Where returns a condition to add to a query.

type Query

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

Query contains a compiled query.

func New

func New(prefix string) *Query

New creates a new query with the supplied prefix.

func ParseQuery

func ParseQuery(query string) (*Query, error)

ParseQuery parses a plaintext query. Special characters (that must be escaped with a '\') are: `\()` and any whitespaces.

func (*Query) Check

func (q *Query) Check() (*Query, error)

Check checks for errors in the query.

func (*Query) DatabaseKeyPrefix

func (q *Query) DatabaseKeyPrefix() string

DatabaseKeyPrefix returns the key prefix for the database.

func (*Query) DatabaseName

func (q *Query) DatabaseName() string

DatabaseName returns the name of the database.

func (*Query) IsChecked

func (q *Query) IsChecked() bool

IsChecked returns whether they query was checked.

func (*Query) Limit

func (q *Query) Limit(limit int) *Query

Limit limits the number of returned results.

func (*Query) Matches

func (q *Query) Matches(r record.Record) bool

Matches checks whether the query matches the supplied database record.

func (*Query) MatchesAccessor

func (q *Query) MatchesAccessor(acc accessor.Accessor) bool

MatchesAccessor checks whether the query matches the supplied accessor (value only).

func (*Query) MatchesKey

func (q *Query) MatchesKey(dbKey string) bool

MatchesKey checks whether the query matches the supplied database key (key without database prefix).

func (*Query) MatchesRecord

func (q *Query) MatchesRecord(r record.Record) bool

MatchesRecord checks whether the query matches the supplied database record (value only).

func (*Query) MustBeValid

func (q *Query) MustBeValid() *Query

MustBeValid checks for errors in the query and panics if there is an error.

func (*Query) Offset

func (q *Query) Offset(offset int) *Query

Offset sets the query offset.

func (*Query) OrderBy

func (q *Query) OrderBy(key string) *Query

OrderBy orders the results by the given key.

func (*Query) Print

func (q *Query) Print() string

Print returns the string representation of the query.

func (*Query) Where

func (q *Query) Where(condition Condition) *Query

Where adds filtering.