Fieldpine Logo Documentation Home  
Library
» Overview
» eLink API

GDS Predicates Technical Information


GDS uses a consistent way of defining predicates on HTTP GET requests and distributed network queries. While each individual bucket is free to interpret predicates (F9) however it wishes, most implement the format described here. This formats primary aim is to be machine readable first and foremost. It also matches internal grid processing protocols used with GDS.

General Form

The general format of a predicate is

9=fNNN,OPERATER,OP-ARG(s)

NNN is the input field number to match against.

OPERATOR (Test Type) is a code taken from the table below

CodeAlternativesDescriptionOP-ARGSExamples
0=, eqExact Equals. For string values this includes being case sensitive so that abc does not equal ABC. The SQL equivalent is where fNNN=ARGA single value. 9=f150,0,3
9=f150,=,3
Select where f150=3
1<, lt< Less than. 9=f150,1,3
9=f150,lt,3
Select where f150<3
2<=, le<=
3>>
4>=>=
5<>, !=<> (not equal)
7likelike
8like.ignorecaselike ignoring case9=f150,8,ABSelect where f150 is like %ab% or %AB% or %aB% or %Ab%
9=ignorecaseEquals ignoring casef100,=ignorecase,catselect where LOWER(f100) = LOWER(cat)
10NULL management.
11starting.ignorecaseStarting with, where the beginning of the value matches the supplied pattern
16startingStarting with, where the beginning of the value matches the supplied pattern

OP-ARGs are encoded using eLink GDS standardised encoding formats ONLY.

Examples

9=f100,0,23
Restrict to rows where f100 is equal to 23

9=f101,8,ABC
Restrict to rows where f100 contains ABC. In SQL, the format would be "where f101 like '%ABC%' ignore case"