TOC

  1. Intro
  2. TagModel
  3. Structure
  4. TimeZones
  5. Units
  6. Grids
  7. Filters
    1. Overview
    2. Usage
    3. Grammar
  8. Zinc
  9. Json
  10. Trio
  11. Csv
  12. Rest
  13. Ops
  14. Auth
  15. VFDs
  16. Networks
  17. Energy
  18. Zones
  19. AHUs
  20. VAVs
  21. UnitaryEquips
  22. Chillers
  23. Boilers
  24. Tanks
  25. ElecPanels
  26. Lighting
  27. Builds
  28. Bacnet
  29. ChangeLog
  30. License
◄Grids Zinc►

Filters

Overview

Filters are a simple query language used to construct predicates for matching entities. Filters are used by the Rest read op to perform ad hoc queries against a server.

Usage

The simple usage is just a tag name which matches any record which contains a tag (regardless of its value):

site  // query any record with the "site" tag

To match a tag value you can use any of the equality or comparison operators:

geoPostalCode == "23220"   // equal to
geoPostalCode != "23220"   // not equal to
curVal < 75                // less than
curVal <= 75               // less than or equal to
curVal > 75                // greater than
curVal >= 75               // greater than or equal to

The scalars to compare against are encoded using Zinc encoding (with couple exceptions noted below).

You can combine filters using and, or, or not:

site or equip             // has site or equip tag
equip and hvac            // has equip and hvac tag
equip and not ahu         // has equip tag, but not the ahu tag

You use the -> to dereference a tag which has a Ref value. For example if your equip rec has a siteRef tag that references the site, you can query for equip in a given city such as:

equip and siteRef->geoCity == "Chicago"

The way to read the above expression is match an entity if:

Grammar

The formal grammar of the filter langauge:

<filter>     :=  <condOr>
<condOr>     :=  <condAnd> ("or" <condAnd>)*
<condAnd>    :=  <term> ("and" <term>)*
<term>       :=  <parens> | <has> | <missing> | <cmp>
<parens>     :=  "(" <filter> ")"
<has>        :=  <path>
<missing>    :=  "not" <path>
<cmp>        :=  <path> <cmpOp> <val>
<cmpOp>      :=  "=" | "!=" | "<" | "<=" | ">" | ">="
<path>       :=  <name> ("->" <name>)*

<val>        :=  <bool> | <ref> | <str> | <uri> |
                 <number> | <date> | <time>
<bool>       := "true" or "false"
<number>     := same as Zinc (keywords not supported INF, -INF, NaN)
<ref>        := same as Zinc
<str>        := same as Zinc
<uri>        := same as Zinc
<date>       := same as Zinc
<time>       := same as Zinc

See Zinc grammar for productions reused from Zinc. Note that Marker, Bin, and DateTime scalars are not supported. Bools are encoded as "true" or "false" (Zinc encodes as "T" or "F").

◄Grids Zinc►